Sericitic and Advanced Argillic Mineral Assemblages and Their Relationship
to Copper Mineralization, Resolution Porphyry Cu-(Mo) Deposit, Superior
District, Pinal County, Arizona
by
Alexander Raine Winant
A Prepublication Manuscript Submitted to the Faculty of the
DEPARTMENT OF GEOSCIENCES
In Partial Fulfillment of the Requirements
for the Degree of
MASTER OF SCIENCE
In the Graduate College
THE UNIVERSITY OF ARIZONA
2010
1
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accepted as fulfilling the research requirement for the degree of Master of Science.
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2
Sericitic and Advanced Argillic Mineral Assemblages and
Their Relationship to Copper Mineralization,
Resolution Porphyry Cu-(Mo) Deposit, Superior District,
Pinal County, Arizona
Alexander R. Winant and Eric Seedorff
Lowell Institute for Mineral Resources, Department of Geosciences, University of Arizona
1040 East Fourth Street, Tucson, Arizona 85721-0077
Hamish R. Martin
Resolution Copper Company, 47206 N. Magma Shaft #9 Road, Superior, Arizona
85273
Frank K. Mazdab and Mark D. Barton
Lowell Institute for Mineral Resources, Department of Geosciences, University of Arizona
1040 East Fourth Street, Tucson, Arizona 85721-0077
3
Abstract
The Resolution deposit is a giant, deep, high-grade deposit in the Laramide porphyry
copper province of Arizona that is currently being developed. This study focuses on the features
at Resolution that formed from acidic hydrothermal fluids (including sericitic and advanced
argillic alteration types) that are well developed in the upper part of the system. The distribution
of alteration-mineralization features are illustrated along two, roughly perpendicular fences of
drill holes that were logged with concurrent mineral identifications made with a PIMA™
infrared spectrometer and ultraviolet light and supplemented with subsequent reflected and
transmitted light petrographic observations. Hydrothermal minerals formed during intense
hydrolytic alteration at Resolution commonly are related to multiple superimposed, crosscutting
events. Though showing some degree of stratigraphic control, particularly at deep levels, the
distribution of hydrothermal minerals and mineral assemblages shows only weak degrees of
structural control at the deposit scale.
The intermediate sulfidation opaque assemblages containing chalcopyrite
characterize
the many hydrothermal mineral assemblages that formed potassic alteration of igneous rocks,
skarn, and calc-silicate hornfels, which are best developed outside the region of this study.
Earlier sericitically altered rocks contain pyrite ± chalcopyrite, but later sericitic and advanced
argillic assemblages contain higher sulfidation state opaque assemblages, such as pyrite + bornite
± chalcocite with kaolinite, dickite, and topaz, with lesser alunite, pyrophyllite, and zunyite.
4
Veins with assemblages characteristic of advanced argillic alteration consistently offset veins
associated with sericitic alteration. Most of the advanced argillic assemblages at Resolution
formed at relatively low temperatures, stable with kaolinite and dickite.
Resolution contains fairly high levels of fluorine. The most important fluorine-bearing
minerals are biotite (~3-4 wt% F), topaz (~11-12 wt% F), fluorite (~49 wt% F), and sericite (~1
wt% F), although other fluorine-bearing phases also are locally present (e.g., zunyite, 6-7 wt% F).
Topaz formed at Resolution during advanced argillic alteration and the mineral has a relatively
fluorine-poor composition (XF-tpz ~0.6), as is topaz from other base-metal lode deposits such as
Butte, in contrast to topaz in those porphyry deposits in which a more fluorine-rich topaz occurs
in sericitic and potassic assemblages.
Resolution is a relatively arsenic-poor system, in strong contrast to the nearby Magma
vein system. The deeper part of the ore body, where potassic alteration dominates, is nearly
arsenic-free, whereas the upper part of the copper ore body is arsenic-bearing. Although enargite
has been observed petrographically, arsenic occurring in solid solution in other sulfides (e.g.,
arsenic-bearing pyrite) may be responsible for many of the local spikes in arsenic content at
Resolution.
Introduction
Intense hydrolytic alteration of the sericitic and advanced argillic types, though known
also from other types of hydrothermal ore deposits, occurs commonly in three related types of
5
magmatic-hydrothermal ore deposits, porphyry deposits, base-metal lode deposits, and
acid-sulfate or high-sulfidation epithermal deposits (Meyer and Hemley, 1967; Hemley et al.,
1980; Einaudi, 1982; Arribas, 1995; Seedorff et al., 2005a). Intense hydrolytic alteration,
regardless of deposit type, can be pervasive or can be confined to structures or stratigraphic units;
rocks exhibiting intense hydrolytic alteration can be barren to highly mineralized. Where
mineralized, high- to very-high sulfidation state opaque minerals commonly are associated with
advanced argillic alteration of silicate minerals (Meyer and Hemley, 1967; Einaudi, 1982;
Einaudi et al., 2003).
Intense hydrolytic alteration is characteristic of shallower levels of certain porphyry
systems (e.g., Red Mountain, Arizona; Resolution, Arizona; El Salvador, Chile; Central deposit,
Oyu Tolgoi, Mongolia) and base-metal lode deposits (e.g., Bisbee, Arizona), though sericitic and
advanced argillic alteration can persist to deep levels, as at Butte, Montana (Bryant, 1968; Meyer
et al., 1968; Corn, 1975; Gustafson and Hunt, 1975; Bodnar and Beane, 1980; Hedenquist and
Lowenstern, 1994; Reed and Meyer, 1999; Watanabe and Hedenquist, 2001; Manske and Paul,
2002; Khashgerel et al., 2009). For the high-sulfidation epithermal deposits, links to porphyry
systems are well established in certain cases (e.g., Lepanto- Far Southeast in the Philippines) but
to date are lacking in many other districts (e.g., Goldfield, Nevada, and Yanacocha, Peru)
(Einaudi, 1982; Arribas et al., 1995; Harvey et al., 1999; Sillitoe and Hedenquist, 2003).
Likewise, it is not necessarily clear whether fluids that formed intense hydrolytic alteration
represent evolution of fluids that produced potassic alteration at earlier stages or whether they
6
represent a temporally distinct hydrothermal system (e.g., Meyer et al., 1968; Brimhall and
Ghiorso, 1983).
Rocks exhibiting intense hydrolytic alteration commonly represent a special challenge in
identifying mineral assemblages, defined as a group of minerals that appear to be stable together
at the mesoscopic scale and to have formed contemporaneously (e.g., Seedorff et al., 2005a). In
many cases, the hydrothermal minerals clearly are related to multiple superimposed, crosscutting
events, yet the identity of the products of each event may be difficult to determine at the hand
specimen scale. Moreover, the silicate minerals commonly are light colored, fine-grained, and
difficult to identify with the naked eye or hand lens and in some cases petrographically, such as
distinguishing between sericite and pyrophyllite. Even where the minerals can be determined by
with aid of infrared spectrometers and X-ray diffraction, the textural relationships generally are
lost at the spatial scales of such determinations, i.e., the minerals identified may have formed in
multiple events, so the nature of the mineral assemblage remains uncertain. For these reasons,
the identification of mineral assemblages within areas of intense hydrolytic alteration commonly
is avoided or not deemed possible (e.g., Khashgerel et al., 2006), thereby limiting the types of
geochemical or genetic conclusions that might be drawn.
This study was conducted at the Resolution deposit in Arizona. The study focuses on the
upper part of the Resolution system where sericitic and advanced argillic assemblages are
prevalent, building on work by Manske and Paul (2002), Ballantyne et al. (2003), Schwarz
(2007), and the geologic staff at Resolution, especially on previous work by Troutman (2001)
7
and Harrison (2007) on sericitic and advanced argillic alteration. The purposes of this study are
to document the distribution, abundance, and compositions of associated hydrothermal minerals,
to attempt to define the mineral assemblages that constitute sericitic and advanced argillic
alteration, to determine the lateral and vertical changes in abundance of sericitic and advanced
argillic alteration,, and to document the relative ages of associated veins. We show that acidic
hydrothermal fluids at Resolution formed a variety of vein types and mineral assemblages,
though some uncertainty remains in defining assemblages. Most assemblages at Resolution are
of the sericitic and advanced argillic types, but they include some assemblages that are
transitional between those two types. Most of the advanced argillic assemblages formed at
relatively low temperatures, stable with kaolinite and dickite. The Resolution deposit contains
fairly high levels of fluorine (Schwarz, 2007), and we document that fluorine occurs mainly in
topaz, sheet silicate minerals, and fluorite and that the onset of topaz deposition occurred during
advanced argillic alteration. Resolution is a relatively arsenic-poor system (e.g., Fig. 15 of
Manske and Paul, 2002), in strong contrast to the nearby Magma vein system, and we show that
local spikes in arsenic content at Resolution probably occur mostly where arsenic occurs as a
minor component in other sulfides (e.g., arsenic-bearing pyrite), rather than as occurrences of
discrete arsenic minerals, such as tennantite or enargite.
After reviewing the geologic setting of the district, this paper will illustrate the
distribution of key metals and hydrothermal minerals, document the advanced argillic and
sericitic assemblages and their relative ages as documented during core logging of two,
8
approximately orthogonal fences of drill holes, with concurrent use of a PIMA™ infrared
spectrometer and ultraviolet light and subsequent reflected and transmitted light petrographic
observations to aid mineral identification. Elemental distributions and mineral compositions that
were determined by electron microprobe and the scanning electron microscope, especially of
arsenic- and fluorine-bearing minerals, further constrain the geochemical environment of
hydrothermal fluids. The silicate components of the assemblages are classified into alteration
types using activity ratio diagrams, and the sulfide-oxide component of the assemblages are
classified by sulfidation state, to assess the degree of correlation between advanced argillic
alteration and high-sulfidation state mineral assemblages. The geochemical stabilities of
successive mineral assemblages are used to define the possible evolutionary paths of fluids. The
results have potential applications to exploration, production planning, milling, and smelting.
Geologic Setting
The Resolution deposit is located in the Superior (Pioneer) district, Pinal County, Arizona,
north of Tucson and east of Phoenix (Fig. 1). Porphyry-related deposits in the Superior district
formed within the Late Cretaceous to early Tertiary Laramide arc, which has been variably
dismembered and tilted by mid- to late Tertiary normal faulting (Titley, 1982; Wilkins and
Heidrick, 1995; Lang and Titley, 1998; Maher, 2008; Seedorff et al., 2008; Stavast et al., 2008).
The geology of the Superior district has been mapped and described by Peterson (1969),
Hammer and Peterson (1968), and Manske and Paul (2002), and is summarized here. The
9
Proterozoic Pinal Schist forms the local basement of the district and adjacent areas and is
overlain by Proterozoic strata of the Apache Group, which consists in ascending order of the
Pioneer Formation, the Dripping Spring Quartzite, the Mescal Limestone, and locally by basaltic
lava flows. The Apache Group was intruded at 1.1 Ga by a series of diabase sills, which also
intrude the underlying Pinal Schist as sheets of similar orientation. The Apache Group is capped
by the Proterozoic Troy Quartzite. The Proterozoic strata are overlain disconformably by >800 m
of Paleozoic carbonate and clastic rocks that now dip east at 35˚ to 40˚. The Paleozoic
stratigraphic section includes the Cambrian Bolsa Quartzite, Devonian Martin Formation,
Mississippian Escabrosa Limestone, and Pennsylvanian-Permian Naco Group. Mesozoic
sedimentary and intermediate volcanic and volcaniclastic rocks, correlated regionally with
quartzites of the Pinkard Formation and with the Williamson Canyon Volcanics, respectively, are
preserved inside a down-faulted structural block that includes the Resolution deposit. The
Mesozoic, Paleozoic, and Proterozoic rocks are intruded by felsic porphyry dikes and sills,
perhaps soon after periods of thrust, normal, and strike-slip faulting (Manske and Paul, 2002).
Laramide rocks have proven to be a geochronologic challenge to date accurately, but the
Resolution center probably includes rocks formed at ~63 Ma, and other porphyries in the district
may be as old as ~69 Ma (Ballantyne et al., 2003; Seedorff et al., 2005b).
Pre-Tertiary rocks are unconformably overlain by the Whitetail Conglomerate, an
east-dipping growth sequence deposited in a half-graben that constituted the Whitetail
sedimentary basin. The basal unconformity and the lowest beds exposed in this sequence dip at
10
least 25° to the east, with strata higher in the sequence dipping less steeply. The 25° dip likely
represent the minimum amount of post-ore eastward tilting of the deposit, although the actual
amount of tilting is uncertain. The Whitetail Conglomerate is overlain by the Apache Leap Tuff,
which is a welded ash-flow tuff dated at 18.6 Ma that can exceed 400 m in thickness and dips 10˚
to 15˚ to the east (Peterson, 1969, 1979; Ferguson et al., 1998; McIntosh and Ferguson, 1998).
Until the last decade, the Superior district was known primarily for production from the
Magma vein and from related mantos that replace selected beds in the Paleozoic carbonate
sequence (Short et al., 1943; Gustafson, 1961; Hammer and Peterson, 1968; Paul and Knight,
1995; Friehauf, 1998; Pareja, 1998), and the Magma vein and mantos have similarities to other
base-metal lode deposits, such as the Butte, Montana, and Cerro de Pasco, Peru (Einaudi, 1982).
The Magma vein and mantos occur north of the town of Superior and extend eastward under the
Apache Leap Tuff toward the #9 Shaft. The Resolution deposit occurs beneath the Apache Leap
Tuff, largely south and east of the Magma vein (Manske and Paul, 2002; Ballantyne et al., 2003;
Schwarz, 2007; Fig. 1). Manske and Paul (2002), among others, have argued that the Magma
vein and Resolution deposit are distinct magmatic-hydrothermal systems, but the relationship
between the two centers, Magma and Resolution, remains controversial.
The Resolution Deposit
The Resolution deposit is a major porphyry copper deposit first discovered in the
mid-1990s (Manske and Paul, 2002; Paul and Manske, 2005). The known extent of the deposit
11
and its development toward becoming a mine have been enhanced more recently by Resolution
Copper Mining LLC (Ballantyne et al, 2003; Schwarz, 2007; Anonymous, 2010), a joint venture
between Resolution Copper Company (55%), a subsidiary of Rio Tinto plc, and BHP Copper, Inc.
(45%), a subsidiary of BHP Billiton Ltd. The top of the ore body is ~1.5 km below the surface,
and Resolution Copper Mining LLC plans to use a panel cave method to mine the deposit
beginning in the year 2020. At this time, the deposit is known only from drill core obtained from
holes that are primarily greater than 2 km in length, steeply plunging, and irregularly spaced (e.g.,
Anonymous, 2008). Resolution Copper Mining LLC reported in March 2010 that the deposit has
an Inferred Mineral Resource of 1.624 billion tonnes at a grade of 1.47 per cent copper and 0.037
per cent molybdenum (Anonymous, 2010).
The Resolution deposit is geologically distinctive for several reasons (Manske and Paul,
2002; Schwarz, 2007), including: (1) High hypogene copper grades occur in a variety of
environments, principally as chalcopyrite in diabase, calc-silicate rocks, and intermediate
volcanic rocks, which tend to occur at relatively deep (pre-tilt) levels, but also as bornite ±
digenite in rocks that tend to occur at shallower levels. (2) Large volumes of rock are affected by
moderate to intense hydrolytic alteration of the sericitic and advanced argillic types. (3) Bornite,
rather than chalcopyrite, is abundant in intense sericitic alteration. (4) Enargite is rare to absent in
advanced argillic alteration, as is tennantite in sericitic alteration, in marked contrast to the
nearby Magma vein.
12
Methods
At the project site, the senior author relogged >2,500 m of core from eight drill holes to
supplement existing drill logs and multi-element assays, with a focus on attempting to identify
the hydrothermal mineral assemblages (i.e., silicate, sulfides, and other minerals) in vein fillings
and alteration envelopes and the crosscutting relationships between partially superimposed
events. The holes selected for logging are oriented along two crossing sections, with data
projected onto sections oriented at azimuths of approximately 100 and 180 (Fig. 1), which are
referred to as nominally east-west and north-south sections, respectively.
Geologic logging included using a hand lens to observe and record sulfide and silicate
volume percent estimates, to estimate abundances of alteration minerals, and to measure veins
(angle to core axis, abundances, widths). Data simultaneously were collected with the PIMA™
(Portable Infrared Mineral Analyzer) short-wave infrared spectrometer during every logging
interval, and samples of drill core frequently also were observed under ultraviolet (UV)
illumination to check for the presence of hydrothermal topaz, which strongly fluoresces
blue-white under short-wave UV (Marsh, 2002). Although the PIMA™ spectrometer
occasionally gives spurious information (e.g., indicating presence of stilbite where none is
present), previous work by Troutman (2001) at Resolution that linked visual core logging and
PIMA™ spectrometer analysis in the field with petrography and X-ray diffraction analysis in the
laboratory demonstrated the overall utility of using the PIMA™ spectrometer to aid in
identifying the fine-grained minerals that are typical of sericitic and advanced argillic alteration
13
at this deposit. In this study, 355 samples were analyzed using the PIMA™ and short-wave UV.
The various geologic and geochemical observations and measurements subsequently were
plotted on the two cross sections using Microsoft Excel, using color-coded data points to portray
intensity or grade, with the purpose of examining spatial distributions and correlations. The most
instructive features were imported into a drafting program, where they were manually contoured,
as described further in a later section.
In laboratories at the University of Arizona, transmitted and reflected light petrography
was carried out on 70 polished thin sections, and these data were added to the cross sections and
incorporated into tables. A Scanning Electron Microscope (SEM) and an electron microprobe
were used to confirm the identities of minerals, as well as to confirm presence of and/or to
quantity the abundance of certain elements, such as arsenic and fluorine. A CAMECA SX 50
electron microprobe was used to obtain quantitative compositions of biotite, sericite, topaz, and
clay minerals using routine methods and standards.
Distribution of Rock Types, Alteration, and Selected Elements
Geologic cross sections and assays from the Resolution project provide the geologic and
geochemical framework of the deposit and a basis for interpreting data collected in this study.
The distribution of rock types and alteration zones are taken directly from the block model that
was developed by Resolution geologists, which is based on drill holes throughout the deposit,
rectified in three dimensions. The understanding of the geology continues to be improved by
14
continued study and analysis and by drilling additional holes (e.g., Anonymous, 2008, 2010),
The present understanding of the distribution of rock types within the deposit generally follows
that of Ballantyne et al. (2003), but the structural history of the district remains uncertain. There
are both pre-ore and post-ore faults in the district with large displacement, but the faults present
within the cross sections have relatively modest offsets and are thought to be largely pre-ore in
age.
Multi-element geochemical data from drill holes in the two selected cross sections were
contoured by hand, attempting to be consistent with existing geologic observations (e.g., degree
of lithologic control of mineralization). Nonetheless, these contours are non-unique
interpretations and are subject to considerable uncertainty, given the current spacing and
orientation of drill holes.
Two cross sections are shown here (Fig. 1). The deposit is elongate in an east-west
direction, and the east-west cross section illustrates at least some of the effects of eastward,
post-ore tilting of the deposit. Additional holes drilled farther east and to greater depths may be
required to describe the full geometry and size of the system. The north-south section, in contrast,
is a slice through the system that largely obscures the effects of tilting by movement on normal
faults and seemingly displays the full north-south extent of the Resolution system.
Distribution of rock types
Figure 2 shows the distribution of rock types at Resolution in both cross sections.
Beginning from the bottom of the cross sections, the first ~ 600 m consists mostly of schist
15
overlain by stratified sedimentary rocks, consisting mostly of Proterozoic Pinal Schist, quartzite,
and limestone (mostly converted to skarn), with sills and sheets of diabase, Paleozoic quartzite
and limestone, and Cretaceous quartzite (Fig. 2). A 600- to 700-meter thick Cretaceous
volcaniclastic unit that dips to the northeast overlies this sequence of units. Two main types of
porphyry stocks and dikes intrude the Cretaceous volcaniclastic unit and older rocks, including a
porphyry stock on the eastern side of the east-west section (Fig. 2). The pre-Tertiary units, none
of which is post-ore in age, are overlain by Tertiary post-ore units, the Whitetail Conglomerate
and overlying Apache Leap Tuff (Fig. 2).
Distribution of alteration zones
The Resolution block model includes a field for the dominant alteration type or zone (Fig.
3). The model describes six alteration zones, the first five of which are hypogene in origin:
chlorite ± epidote ± calcite ± adularia (referred to as propylitic), quartz + sericite + pyrite
(sericitic), biotite ± K-feldspar ± chlorite ± anhydrite (potassic), quartz + sericite + pyrite
overprinting biotite ± K-feldspar (sericitic/potassic), dickite ± pyrophyllite ± alunite ± zunyite ±
andalusite (advanced argillic), and the supergene hematitic leached cap (Fig. 3). In this
simplified view, the alteration in sedimentary rocks is assigned the same type as those of nearby
igneous rocks.
The base of the cross sections is composed of potassically altered rocks or potassically
altered rocks with a sericitic overprint (Fig. 3); these are confined mainly to Proterozoic schist,
diabase, and lesser Mescal Limestone. Rocks altered to sericitic and advanced argillic alteration
16
occupy a large fraction of the model (Fig. 3), affecting large volumes of porphyry and extending
out into Cretaceous volcaniclastic rocks and other lithologies, including quartzites and locally
limestones and diabase. Aside from the potassic alteration that dominates the deeper parts of the
system, the two types of hydrolytic alteration in the block model generally show a central core of
advanced argillic alteration, giving way upward and outward to sericitic alteration (Fig. 3). The
Tertiary unconformity clips the top of the core of advanced argillic alteration in certain sections;
there, advanced argillic alteration may have extended further upward, perhaps as a pipe or an
upward-expanding funnel (see also Fig. 15 of Manske and Paul, 2002). In the north-south section,
sericitic alteration in turn is zoned upward and outward in both directions to propylitic alteration.
On the east-west section, the zoning pattern is incomplete on the eastern side of the section
where sericitic alteration pervades a porphyry stock, because of an absence of drilling further to
the east where the Tertiary overburden continues to thicken (Fig. 3). The block model locally
shows “fingers” of advanced argillic alteration extending downward directly into potassic
alteration, although sericitic alteration also may underlie advanced argillic alteration (Fig. 3). The
hematitic leached cap was formed in Cretaceous volcaniclastic rocks and is overlain by the
Whitetail Conglomerate.
Distributions of copper, arsenic, iron, and sulfur
Assays of selected elements in the Resolution database are useful for addressing aspects
of the distribution of alteration-mineralization assemblages and possible linkages between
silicate and sulfide mineral assemblages (e.g., Meyer and Hemley, 1967). Data are presented here
17
for copper, arsenic, iron, and sulfur.
Copper: Copper grades exhibit a strong control by host rock lithology (Anonymous,
2008). The highest copper grades (>3 wt%) flare out from the upper volumes of porphyry into
Cretaceous volcaniclastic rocks and in beds of Proterozoic Mescal Limestone and sheets of
diabase (Fig. 4). Copper grades of 1 to 3 wt% can occur in most lithologies with the exception of
Proterozoic Pinal Schist. The highest copper grades are observed mostly in advanced argillic
altered rocks, although there are significant volumes of rock interpreted as sericitic,
sericitic/potassic, and potassic alteration in the RCC alteration block model. Cretaceous and
Proterozoic quartzites generally have lower copper grades than adjacent rock units.
Arsenic: As noted by previous workers (e.g., Fig. 15 of Manske and Paul, 2002; Schwarz,
2007), Resolution is a relatively arsenic-poor system. Troutman (2001), Manske and Paul (2002),
and Harrison (2007) did not report observing either enargite or tennantite. These minerals also
were not observed in this study, although petrographers for Resolution have identified enargite in
thin section. Manske and Paul (2002) note that it is uncommon for arsenic levels to exceed 100
ppm, even in areas with abundant chalcocite/digenite with copper grades >1 percent, and fewer
than 2% of the intervals in the present Resolution assay database exceed 300 ppm As. Arsenic
assays, nonetheless, do display a systematic spatial distribution. In this study, arsenic assays from
drill holes in the two cross sections considered herein are contoured. The upper part of the copper
ore body is arsenic-bearing in both cross sections (cf. Fig. 5 and Fig. 4), whereas the deeper part
of the ore body, where potassic alteration dominates (Fig. 4), is nearly arsenic-free (Fig. 5).
18
Representative samples from intervals with elevated arsenic levels that were logged in
this study subsequently were examined in reflected light and with a Scanning Electron
Microscope (SEM) to assess the mineralogic host of arsenic. Neither enargite nor tennantite was
detected; rather, rocks with high arsenic levels showed a relatively uniform distribution of the
element in other sulfide minerals, such that arsenic-bearing pyrite is probably the source of most
local spikes in arsenic abundance [Fig. 6].
Iron: Iron contents can reflect both primary iron contents (e.g., high in diabase and low in
quartzite) and hydrothermal modifications, especially by metasomatic addition of iron during
hydrothermal alteration-mineralization, mostly as iron and copper-iron sulfide minerals.
Nonetheless, the highest contents of iron (Fig. 7) largely coincide with regions of advanced
argillic and sericitic alteration, extending downward into the underlying area of potassic
alteration (Fig. 3). Iron is enriched, however, on the northern part of the north-south section (Fig.
7B), where advanced argillic alteration is better developed (Fig. 3B). The distribution of iron is
even more asymmetric on the east-west section (Fig. 7A, where the highest iron contents also
occur within advanced argillic alteration, and the contours of iron abundance either truncate
upward and eastward against the tilted Tertiary erosion surface and/or iron contents diminish
eastward into a body of relatively silicic porphyry. The highest iron contents (>10wt%) occur
almost exclusively in Cretaceous volcaniclastic rocks and Mescal Limestone For comparison,
relatively fresh diabase contains ~6-10 wt% Fe, as 8-11 wt% FeO and 1-3 wt% Fe2O3 (e.g.,
Wrucke, 1989).
19
Sulfur: Sulfur contents almost entirely reflect metasomatic additions of sulfur as sulfate
(mostly in hydrothermal anhydrite) or as various sulfide minerals. As in the case of iron, sulfur is
most concentrated in the northern and western regions of the cross sections (Fig. 8). Highest
sulfur contents (>10 wt% S) are in Cretaceous volcaniclastic rocks, Mescal Limestone, diabase,
and porphyry. Sulfur contents of >10 wt% S also correspond mostly to regions of advanced
argillically altered rocks and, to a lesser extent, sericitically altered rocks.
Key hydrothermal minerals: Distribution and compositions
The distribution and abundance of key hydrothermal minerals are presented in Figures 9
to 15, with supporting petrographic observations in Figure 16, which will lead subsequently to an
interpretation of the hydrothermal mineral assemblages. Representative mineral compositions
from a reconnaissance electron microprobe study are presented in Tables 1 and 2, and complete
results are present in an appendix of Winant (2010). The descriptions are grouped as follows:
(kaolinitic) clay, sericite, other minerals commonly associated with, though not necessarily
characteristic of, advanced argillic alteration in porphyry copper systems (topaz, pyrophyllite,
zunyite, alunite, and APS minerals) are followed by other silicate and non-sulfide minerals, and
finally various sulfide minerals.
The distributions are based principally on visual estimates made during drill logging, but
in some cases other types of information also were available, including PIMA™ spectrometer
measurements and petrographic observations (e.g., eight types of data were consulted to derive
contours of intensity of advanced argillic and sericitic alteration). The data were manually
20
contoured, with qualitative to semi-quantitative contour intervals chosen based on the resolution
of the data. Contours are shown with solid lines where interpolated between the senior author’s
observations in logged portions of drill holes; dashed lines represent inferred extensions of those
contours based on data other than those drill logs.
Clay: The term clay here refers only to the aluminum silicates kaolinite, dickite, and
halloysite, identified principally with the PIMA™ spectrometer. Although montmorillonite
(smectite) is also a clay mineral, it is discussed separately below.
Although kaolinite occurs within the leached cap and there is probably all or in part of
supergene origin (e.g., Troutman, 2001), most of the kaolin group minerals logged at Resolution
occur with pyrite and other sulfides, where the clay minerals are interpreted to be of hypogene
origin (Fig. 16D). The occurrence of kaolin group minerals at Resolution includes white kaolinite
in strongly silicified zones containing bornite ± chalcocite and massive translucent pale green
dickite with pyrite, bornite, and chalcocite (Troutman, 2001; Manske and Paul, 2002). The kaolin
group minerals are present mostly in two general areas: (1) extending out from porphyry through
Cretaceous volcaniclastic rocks, and (2) stratabound occurrences within certain sedimentary
units in the lower part of the cross sections (Figs. 2 and 9). The regions with the most abundant
kaolin group minerals coincide with regions of the RCC block model that are assigned to the
advanced argillic alteration zone but extending into the sericitic zone, whereas moderate
abundances of clay extend downward into the potassic zone and outward into the propylitic zone
(Figs. 3 and 9). Microprobe analyses of 11 kaolin group minerals contain ~0.2 to 1.1 wt% F;
21
representative analyses are shown in Table 1.
Sericite: PIMA™ measurements identified 170 samples containing muscovite and 104
samples containing illite (out of a total 253 measurements), supported by petrographic
observations (Fig. 16D,E). These minerals were grouped together for the purposes of describing
sericitically altered rock. High sericite values are observed across the two cross sections (Fig. 10);
rocks containing such values include Cretaceous volcaniclastic rocks, Cretaceous quartzites,
diabase, Mescal limestone, Pinal Schist, and quartzite (Fig. 2). High sericite values are contoured
primarily in areas that the RCC block model assigns to the advanced argillic, sericitic, and
sericitic/potassic alteration zones (Fig. 3).
The electron microprobe was used to analyze 16 grains of sericite, and representative
analyses are reported in Table 1. The compositions vary widely between 2.9 and 9.4 wt% K2O
with negligible Na2O, and none of the analyzed grains is a dioctahedral mica. The mean K2O
content of 6.2 wt%, which corresponds to a mean occupancy of the A site of only ~60%,
implying that the grains have non-muscovite components such as illite (e.g., Bailey, 1984;
Brigatti and Guggenheim, 2002). The major-element compositions of sericite from Resolution
are thus distinct from those of sericite analyzed from some other porphyry systems, in which the
A site generally is almost fully occupied (e.g., Koloula, Guadalcanal, Chivas, 1978; San
Manuel-Kalamazoo, Arizona, Guilbert and Schafer, 1979; Santa Rita, New Mexico, Parry et al.,
1984; Henderson, Colorado, Seedorff and Einaudi, 2004a). The analyzed sericite grains also
contain ~0.5 to 1.7 wt. percent F, which overlaps with but extends to higher levels than observed
22
for clay.
Topaz: Topaz occurs widely across certain parts of the deposit (Fig. 11), and suspected
occurrences can be easily confirmed with the assistance of short-wave UV light, with the
PIMA™ spectrometer, and petrographically (Fig. 16G). As noted by Marsh (2002), topaz occurs
most commonly in alteration envelopes on pyrite veins. Topaz is in equilibrium with bornite and
chalcocite and has not been observed in equilibrium with chalcopyrite.
High and moderate topaz values are observed in Cretaceous volcaniclastic rocks,
porphyry, Cretaceous quartzite, and Proterozoic limestone, quartzite and diabase (Figs. 2 and 11).
About half of the topaz identified in this study occurs in rocks assigned to the advanced argillic
zone in the RCC block model, and the remainder occurs in the sericitic zone (Fig. 3).
Six topaz grains from Resolution were analyzed by electron microprobe; representative
analyses are shown in Table 2. Topaz is uniformly relatively fluorine-poor, containing 11-12 wt
percent F. This is equivalent to a mole fraction of fluor-topaz in topaz solid solution (XF-Topaz) of
0.58 – 0.64. As discussed further in a later section, the fluorine content of topaz helps to
constrain the geochemical environment of its formation (e.g., Barton, 1982; Seedorff, 1986;
Seedorff and Einaudi, 2004b), and XF-Topaz) of ~0.6 is indicative of forming in an advanced
argillic alteration environment.
Pyrophyllite and andalusite: In this study, only three occurrences of pyrophyllite,
confirmed by PIMA™ spectrometer, were documented on the two cross sections that were
studied (Fig. 12). All occurrences of pyrophyllite occur as intergrowths with alunite, chalcocite,
23
and bornite and are present in the same region (Fig. 12) where topaz is present in moderate or
high levels (Fig. 11). Three isolated occurrences of pyrophyllite, with alunite, topaz, and
kaolinite, also were detected in a large-scale infrared spectral reflectance study commissioned by
RCC that used the HyLogger technique in two drill holes (Huntington and Yang, 2009). The
relative paucity of pyrophyllite (Fig. 12) compared to clay (Fig. 9) at Resolution that was
observed in this study is consistent with the earlier observations (Troutman, 2001; Manske and
Paul, 2002; Harrison, 2007).
Andalusite has not been documented at Resolution by earlier workers (Troutman, 2001;
Manske and Paul, 2002; Harrison, 2007; Schwarz, 2007). Andalusite was not observed in core
logging or petrographic examinations made in this study, but several samples submitted by
Resolution geologists for petrographic description have reported local occurrences of andalusite.
Phases indicative of quartz-undersaturated conditions, such as diaspore and corundum (Hemley
et al., 1980), also were not observed.
Alunite: High alunite values occur in the Cretaceous volcaniclastic rocks, although there
are also rare occurrences in Cretaceous quartzites, porphyry, and Proterozoic Mescal Limestone,
diabase, and quartzite (Figs. 2, 12, 16F). High alunite values occur in rocks assigned to both the
advanced argillic and sericitic zone of the RCC block model (Figs. 3 and 12), but RCC has
observed alunite at deep levels of the deposit (e.g., the bottom of hole RES-2A) in rocks assigned
to the zone with sericitic alteration superimposed on potassic alteration. Harrison (2007)
observed several instances of alunite nucleating around cores of APS minerals (see below).
24
APS minerals: Although not observed in this study, aluminum-phosphate-sulfate (APS)
minerals were identified in felsic protoliths by Harrison (2007) using the scanning electron
microscope. Harrison (2007) observed that the minerals occur either with an “irregular, ragged”
texture in kaolinite, form cores of alunite, or occur as “dendritic rapidly cooled masses and zoned
fragments in alunite vein matrix” that may be pseudomorphs of precursor apatite. Electron
microprobe analyses by Harrison (2007) revealed APS compositions intermediate between the
end-members hinsdalite, woodhouseite, and svanbergite, with no evidence for the weilerite
component, as arsenic occurred below the detection limit.
Zunyite: Seven occurrence of zunyite were recorded in this study at the locations plotted
on Figure 12, coinciding with areas of the cross sections that contain moderate and high levels of
topaz. Zunyite also is reported by Troutman (2001) and Manske and Paul (2002). Two electron
microprobe analyses of zunyite, shown in Table 2, contain 6 to 7 wt percent F and more than 2
wt percent Cl.
Biotite, chlorite, and fluorite: In this study, core generally was not logged in areas with
well-developed potassic or propylitic alteration, where biotite and chlorite are abundant.
Nonetheless, several potassically altered specimens were collected, and hydrothermal biotite was
analyzed by electron microprobe (Table 1). The analyzed biotite grains are phlogopitic and
contain 3 to 4 wt. percent F. Though it was not observed in rocks with advanced argillic
alteration, fluorite (~49 wt% F) is also a common gangue mineral in the Resolution deposit
(Schwarz, 2007).
25
Montmorillonite: The PIMA™ spectrometer identified the presence of montmorillonite
as frequently as the other clay minerals and sericite, including in feldspar sites that were soft but
not necessarily pyrite-bearing. Abundances of montmorillonite were not compiled in this study
given the lack of evidence for association with advanced argillic or sericitic alteration. Although
it is possible that this PIMA™ determination is spurious, an alternative is that montmorillonite
was formed as a late, weak hydrolytic overprint at low temperatures, postdating deposition of all
or most sulfides.
Pyrite: Abundances of sulfide minerals were estimated visually during logging of core
and are summarized in terms of relative abundances (Fig. 13). Large volumes of rock contain
high pyrite abundances, which are observed within rocks with advanced argillic alteration and, to
a lesser degree, with sericitically altered rocks (Figs. 3 and 13).
Where pyrite occurs with other sulfides, petrographic observations of sulfide textures
suggest that pyrite was deposited earliest relative to other sulfides (Fig. 16A-C). Pyrite is
commonly observed as angular, brecciated grains and as rounded grains cemented in
bornite-chalcocite-digenite or chalcopyrite-bornite.
Bornite and chalcocite: Supergene chalcocite occurs only locally within the leached cap
(Manske and Paul, 2002). Hypogene examples of both chalcocite and digenite are well
documented at Resolution (e.g., Manske and Paul, 2002, p. 212). Chalcocite and digenite
commonly are intergrown with one another and with bornite (Fig. 16B,C); in addition, there are
uncommon occurrences of hypogene covellite (Harrison, 2007), which was not logged in this
26
study. Indeed, electron microprobe analyses by Harrison (2007) reveal the presence of a variety
of Cu-S phases of various stoichiometries, as well as various compositions of bornite. As noted
by earlier workers (Troutman, 2001; Manske and Paul, 2002; Harrison, 2007), petrographic
evidence suggests that bornite commonly was precipitated around earlier grains of pyrite and
fills cracks in and locally partially replaces pyrite (Fig. 16A-C). Chalcocite appears to be stable
with pyrite, though not necessarily coprecipitated with it (Fig. 16B,C).
In this study, the term chalcocite may be used for any of the Cu-S phases. Given the
common intimate intergrowth of bornite and chalcocite, visual estimates of abundance were
recorded for the sum of bornite and chalcocite (Fig. 14). The highest bornite + chalcocite values
are observed within advanced argillic altered regions and to a lesser extent in rocks assigned to
the sericitic and potassic/sericitic zones in the RCC alteration block model. Resolution geologists
have observed that the highest concentrations of bornite occur at a fairly distinct level at an
elevation of ~ -500m, which is near the base of sericitic alteration with 7-14 vol% pyrite but
outside the highest zone of pyrite. In contrast, the most abundant chalcocite tends to occur at or
slightly above the region of most abundant bornite in the most pyritic rocks.
Chalcopyrite: As shown in Figure 15, high values of chalcopyrite are observed in
advanced argillic, sericitic, and potassic/sericitic altered zones of the RCC alteration block model.
The highest chalcopyrite values are observed consistently in Proterozoic diabase and Mescal
Limestone and more locally in Cretaceous volcaniclastic rocks and porphyry, generally where
altered to potassic assemblages and skarn, which were not the focus of this study. Most of the
27
other occurrences of chalcopyrite are associated with pyritic veins with sericitic alteration
envelopes. No occurrences of chalcopyrite were observed that are unambiguously associated
with advanced argillic assemblages.
Veins and crosscutting relationships
Mineralogy of veins: Many types of hypogene veins were observed and logged, and
photographs of key examples are illustrated in Figure 17. In some cases, the vein filling and the
alteration envelope are distinct; in other cases, they are not, especially where the outer edges of
the envelopes cannot be determined because of a high density of superimposed veins. Similar
veins were grouped into a smaller number of types (Table 3).
Crosscutting relationships: Crosscutting relationships between veins were recorded and
documented during logging, with attempts to avoid potentially deceiving exposures. Figure 18
shows photographs of representative observed crosscutting relationships between veins, and the
petrographic relationships also provide paragenetic constraints (Fig. 16). Table 3 provides a
matrix tabulation of all observations from this study, which focused on a part of the deposit with
abundant sericitic and advanced argillic alteration and thus lacks exposures of many higher
temperature or earlier veins. The table shows that the general paragenesis of veins in the deposit
from older to younger is quartz - molybdenite veins (which may lack alteration envelopes but
generally occur in areas of potassic alteration), through veins related to sericitic alteration,
transitional sericitic-advanced argillic assemblages (e.g., Fig. 16H), and uncommon pyrophylliteand alunite-bearing assemblages, and finally kaolinitic clay-bearing advanced argillic
28
assemblages (Fig. 16D). The data are consistent with the observations of Marsh (2002) that
topaz-bearing veins probably formed broadly contemporaneous with pyrophyllite and kaolinite.
There are a few observations to the lower left of the diagonal of the matrix in Table 3, which is
the field of possible reversals in the vein paragenesis. (See Seedorff and Einaudi, 2004a, for
explanation of terminology regarding reversals and normal and anomalous types of crosscutting
relationships.) Because the detailed paragenesis of veins is only partially constrained by the
relatively limited number of observations in Table 3, the apparent reversals that involve different
veins within the same silicate alteration type (e.g., those advanced argillic veins in the lower
right part of the matrix) probably are not significant. The other apparent reversals are isolated
observations that could represent spurious observations because of cryptic, unrecognized
deceiving exposures or may represent local reversals. In any case, no definitive evidence has
been provided to date for multiple mineralizing events or major reversals in the sequence of
crosscutting veins (Troutman, 2001; Harrison, 2007; A. Schwarz, oral comm., 2007).
Orientations of veins: A variety of data exist regarding vein orientations at Resolution.
The staff geologists collect extensive data on vein orientation based on measurements on
oriented core their correlation with down hole data. One such tool, Wellcad, is a core orientation
program that collects both bore hole televiewer and acoustic resonance imaging data. The
program collects copious amounts of information regarding vein fracture and fault orientations.
An RCC internal technical report (Trout, 2009) that summarizes the vein database reports an
overall vein trend of N30E; the earliest, quartz – molybdenum veins and veins within the
29
porphyry are reported to have a northwesterly strike; chalcopyrite veins strike west; and
chalcocite- and bornite-bearing veins follow a N30E trend. In an earlier study, Troutman (2001)
notes a dominant strike of N55E with southeasterly dips in the northern part of the deposit and
northwesterly dips in the southern part of the deposit for veins associated with sericitic and
advanced argillic alteration.
In this study, vein orientations to core axis were measured (Table 4). Because the portions
of the holes logged in this study are nearly vertical, 90 minus the angle to core axis is the
approximate dip of the vein. These data show that the dips on sericitic veins vary widely,
whereas for veins associated with advanced argillic alteration the orientations are more
systematic, with the angle to core axis generally varying from 0 to 30 degrees, i.e., the present
dip of the veins (i.e., after tilting associated with normal faulting) is steep at ~60-90°. The data of
Troutman (2001) and the Wellcad database suggest that these veins have northeasterly strikes.
Interpretations
Characterization and classification of assemblages into silicate alteration types
As in many deposits where advanced argillic alteration is developed, the assignment of
alteration products at Resolution to hydrothermal mineral assemblages is complicated by the
widespread evidence for superposition of events, the difficulty in some cases of relating
alteration features to particular veins or fluid channels, and the fine-grained nature of many of
the products of hydrolytic alteration. In spite of hundreds of PIMA and UV light determinations,
30
supplemented by petrography and electron microprobe analyses, the ability to identify
hydrothermal mineral assemblages with certainty continuously down a given drill hole remains
impossible’ nonetheless, it is possible to do this discontinuously in many drill holes. The
information gathered from such intervals, as illustrated in Figure 19, can be synthesized to
construct a list of the various mineral assemblages produced by acidic fluids at Resolution (Table
5), even if the assignments are less certain than they might be in other deposits or other parts of
the Resolution deposit, and to assign them to silicate alteration types using the criteria of
Seedorff et al. (2005a). Interpretations rely heavily on the most definitive cases, such as
compelling cases for coprecipitated minerals filling veins (Fig. 17) and petrographic textural
evidence observed here (Fig. 16) and documented in other works (e.g., Troutman, 2001; Harrison,
2007). Given the difficulty of this effort, Table 5 also offers guidance as to the confidence in each
proposed assemblage and an interpretation of the relative abundance of each assemblage. Most
of the assemblages observed (Table 5) either (1) are of the sericitic type (Figs. 16E, 19D,G), (2)
are transitional from sericitic to advanced argillic types (Figs. 16H,19E), or (3) are of the
advanced argillic type (Figs. 16F,G, 19A-C,H).
The intensity of advanced argillic alteration at Resolution is largely governed by the
abundance of kaolinite and dickite (Fig. 9), given the relative lack of pyrophyllite (Fig. 12) and
rarity of andalusite. Among other aluminous minerals, such as topaz (Fig. 11), alunite (Fig. 12),
and zunyite (Fig. 12), that can be present in advanced argillic alteration, only topaz is fairly
abundant at Resolution. The geochemical stabilities of these minerals do not require that the
31
former three minerals form only under advanced argillic conditions (e.g., Barton, 1982; Seedorff,
1986; Seedorff et al., 2005a), and some of these minerals clearly have formed in other deposits in
the sericitic or potassic environments (e.g., Seedorff and Einaudi, 2004a, b). At Resolution, hand
specimen and petrographic observations indicate that topaz in many cases clearly formed in
equilibrium with kaolinite but not with K-feldspar or sericite, although certain quartz-topaz
occurrences are not diagnostic. Nonetheless, the fluorine-poor nature of all topaz grains analyzed
(XF-Topaz of ~0.6) coupled with phase relations (e.g., Barton, 1982; Seedorff and Einaudi 2004b)
indicate that topaz at Resolution probably formed mostly in the advanced argillic environment.
The close association of alunite with pyrophyllite at Resolution also indicates that the few alunite
occurrences known from Resolution also formed in the advanced argillic environment.
Relationship between silicate alteration assemblages and opaque assemblages
At Resolution, the deeper part of the ore body characterized by potassic alteration (e.g.,
Manske and Paul, 2002) contains opaque assemblages of chalcopyrite, chalcopyrite + magnetite,
and chalcopyrite + pyrite, i.e. intermediate sulfidation state assemblages (Einaudi et al., 2003).
As shown in Table 5, a sericitic assemblage with relatively low abundance is characterized by the
intermediate sulfidation state opaque assemblage of chalcopyrite + pyrite. The most abundant
sericitic assemblages, however, are high-sulfidation state assemblages with pyrite, bornite, and
chalcocite (Fig. 19D,G), confirming earlier conclusions of Troutman (2001) and Manske and
Paul (2002) regarding Resolution but differing from observations in many other porphyry
systems (e.g., Einaudi, 1982). High-sulfidation state assemblages persist through transitional
32
advanced argillic-sericitic and advanced argillic assemblages (Table 5). Indeed, three polished
thin sections in this study (e.g., Fig. 19D) contain bornite–chalcocite with sericite but lack
kaolinite, topaz, and/or alunite; nonetheless, the majority of polished thin sections contain
bornite-chalcocite stable with clay and/or topaz. The highest copper grades (>3%) coincide
generally with high abundances of bornite-chalcocite-associated exclusively with zones of
intense advanced argillic alteration and high pyrite content (Figs. 4, 7, 9, 11, 13, 14). As noted
above, enargite is uncommon in high-sulfidation mineral assemblages, as local spikes in arsenic
content correspond primarily with occurrences of arsenic-rich pyrite (Fig. 6). The very-high
sulfidation state assemblage covellite + pyrite, also associated with advanced argillic alteration,
has been reported locally at Resolution (e.g., Harrison, 2007) but was not observed in this study.
Evolutionary paths of fluids
The succession of mineral assemblages (Table 5) with time as documented by
crosscutting relationships (Fig. 18, Table 3), supplemented by petrographic observations (Fig.
16), can be used to deduce evolutionary paths of hydrothermal fluids that can be displayed as
paths across phase diagrams. Although some portions of a path may represent progressive
evolution of a single batch of hydrothermal fluid as it reacts with wall rock, new inputs of fluid,
perhaps varying compositions, may also occur with time.
The sequence of opaque assemblages (Table 5) documented above constitutes an
evolutionary path of increasing sulfidation state with time in the region of the Resolution deposit
examined in this study. This path probably corresponds to a segment of the gently
33
upward-inclined arc of the looping path on a T-fS2 diagram commonly observed in
porphyry-related systems that attain high and very high sulfidation states (e.g., Einaudi et al.,
2003).
Changes in the acidity of the fluid with decreasing temperature are illustrated
schematically in Figure 20. Without better constraints on temperature (e.g., from fluid inclusion
data), a precise path cannot be shown, but the sequence of silicate phases is nonetheless
indicative of a general trajectory based on relative ages of assemblages. The sequence of veins
and mineral assemblages (Tables 3 and 5) indicate that earlier, presumably hotter, fluids were
stable with K-feldspar and/or biotite, producing potassic alteration. Through time, probably
associated with a decline in temperature, the fluid became stable with sericite, although the
potassium-poor compositions of sericite at Resolution (Table 1) suggest that much of this sericite
was produced at fairly low temperatures, approaching or within the nominal stability of illite (Fig.
20). The abundance of kaolinite-dickite and the rarity of pyrophyllite suggest that the path may
have left the sericite field and entered the field of aluminosilicate minerals at fairly low
temperatures (~300ºC) in the vicinity of the pyrophyllite-kaolinite boundary (Fig. 20), coinciding
with the transition from sericitic to advanced argillic alteration. The absence of observations of
diaspore and corundum and the silicification commonly associated with kaolinite (e.g., Troutman,
2001) indicate that the fluid probably was quartz-saturated during advanced argillic alteration at
Resolution (see also Hemley et al., 1980). If the PIMA™ identifications of montmorillonite and
the suggestion that they might represent a late sulfide-absent alteration product are valid (see
34
above), then the fluid, after producing abundant kaolinite, may finally have become less acid at
very late stages (Fig. 20). The path can be compared with other possible paths that might produce
advanced argillic alteration somewhere during their evolution (e.g., Fig. 12 of Seedorff et al,
2005a).
The presence of topaz and its composition offers further insight into the geochemical
evolution of the fluid, as displayed on diagrams involving temperature and activities of K+ and F(Figs. 21, 22). Topaz is commonly observed in association with kaolinite/dickite (Table 5); hence,
the general path of the fluid on these diagrams interpreted to have traversed from the sericite or
muscovite field (without topaz) to a position straddling the topaz-kaolinite boundary while topaz
was deposited. The fluorine-poor compositions of topaz solid solution (Table 2) are consistent
with formation of topaz during advanced argillic alteration at relatively low temperatures of
~300ºC (Figs. 21, 22). The suggestion that at least some of the kaolinite and dickite postdate
topaz (with kaolinite) indicates that the path then headed into the kaolinite-only field (Fig. 22),
perhaps then veering toward higher values of K+/H+ at late stages (if montmorillonite formed
late, see above; Fig. 22). The paths of Figures 21 and 22 are markedly different than those that
produced topaz during potassic and sericitic alteration at Henderson (e.g., Figs. 9, 10, 12 of
Seedorff and Einaudi, 2004b).
35
Discussion
Geometry and characterization of sericitic and advanced alteration
The distribution of sericitic and advanced argillic alteration in porphyry deposits is
variable (e.g., Fig. 10 of Seedorff et al., 2005). In some deposits, advanced argillic alteration
largely is barren (e.g., the lithocap of Sillitoe, 2010), whereas in many systems it can be well
mineralized (e.g., Einaudi et al., 2003; Seedorff et al., 2005). Likewise, there also can be a
general vertical progression from high to low temperature advanced argillic alteration from
deeper to shallow levels, i.e., andalusite to pyrophyllite to kaolinite (e.g., Gustafson and Hunt,
1975; Watanabe and Hedenquist, 2001).
Rocks exhibiting sericitic alteration and advanced argillic alteration at Resolution
generally are mineralized and commonly exhibit high grades and thus do not constitute a barren
lithocap at the preserved levels. Although some uncertainty remains because the top of the
Resolution system has been eroded, the preserved and drilled portion of the pattern suggests that
advanced argillic alteration is commonly enveloped in three dimensions by a thick rind of
sericitic alteration, although in places advanced argillic alteration extended downward into
potassic alteration and may have extended as a pipe or funnel locally upward through the
sericitic rind at levels above the Tertiary erosion surface (Figs. 3, 9, 10). One could regard the
preserved part of Resolution to be the “root” of a zone of advanced argillic alteration, to the
extent that some rocks affected by advanced argillic alteration have been eroded, yet it is notable
that the preserved “root” is overwhelming dominated by kaolinite and dickite, rather than either
36
pyrophyllite or andalusite. Moreover, the relatively potassium-poor compositions of sericite at
Resolution (Table 1) indicates that the uneroded part of the Resolution system that was the
subject of this study also is not the root of sericitic alteration, but rather probably its uppermost
branches. Hence, it seems unlikely that much of the top of the system has been eroded.
Resolution represents an interesting variant on many possible geometries of hydrolytic
alteration in porphyry systems.
The sericitic to advanced argillic transition
Although the identities, distributions, and relative ages of mineral assemblages is crucial
to understanding the geochemical environment of alteration-mineralization and the dynamics of
hydrothermal systems (e.g., Seedorff et al., 2005a), rocks exhibiting hydrolytic alteration
commonly represent a special challenge in identifying mineral assemblages and in many cases is
been regarded as virtually impossible (e.g., Khashgerel et al., 2006). The difficulty is that the
silicate minerals commonly are fine-grained and light colored and difficult to identify with the
naked eye, hand lens, or in some cases even petrographically, such as distinguishing between
sericite and pyrophyllite. Other techniques, such as infrared spectrometers and X-ray diffraction,
aid in mineral identification, but the scale resolution of such determinations commonly results in
the loss of the textural relationships necessary to establish that the minerals formed
contemporaneously in apparent equilibrium.
This study represents one of the few attempts to determine mineral assemblages in areas
of intense hydrolytic alteration and their relative ages (cf., Lipske and Dilles, 2000; Khashgerel
37
et al., 2009). At Resolution, numerous advanced argillic assemblages are present (Table 5),
though most contain kaolinite or dickite, and topaz is abundant. The predominance of kaolinite
contrasts with deposits such as Butte and El Salvador, where andalusite and pyrophyllite are
much more common (e.g., Meyer et al., 1968; Howard, 1972; Brimhall, 1977; Gustafson and
Hunt, 1975; Watanabe and Hedenquist, 2001; Field et al, 2005; Rusk et al., 2008).
Presence of topaz and other fluorine-bearing minerals
Topaz forms in a wide range of geochemical environments (e.g., Barton, 1982). In certain
porphyry molybdenum and tungsten systems, it forms during potassic and sericitic alteration, but
in porphyry copper deposits it forms almost exclusively during advanced argillic alteration
(Seedorff, 1986; Seedorff and Einaudi, 2004b).
Metallurgical tests indicate that Resolution is a relatively fluorine-rich deposit (Schwarz,
2007), although the spatial distribution of fluorine at Resolution is not well known because
fluorine is not routinely assayed. Microprobe analyses conducted in this study (Table 2) indicate
that the most important fluorine-bearing minerals throughout the deposit likely are biotite (~3-4
wt% F), topaz (~11-12 wt% F), fluorite (~49 wt% F), and sericite (~1 wt% F), and other
fluorine-bearing phases also are locally present (e.g., zunyite, 6-7 wt% F). As in other porphyry
copper systems, topaz at Resolution formed during advanced argillic alteration but at relatively
low temperatures with kaolinite, consistent with its relatively fluorine-poor composition (XF-Topaz
= 0.58 – 0.64).
The location and mineralogic host of fluorine in porphyry systems has potential practical
38
implications in processing and environmental storage (e.g., Pangum et al., 1997; Sutter, 2002).
Arsenic abundance and mineralogy in porphyry-related systems
For those porphyry systems that contain considerable arsenic, arsenic is generally present
in intermediate sulfidation state assemblages as tennantite and in high-sulfidation state
assemblages as enargite and luzonite, which tend to be associated with advanced argillic
alteration (e.g., Meyer et al., 1968; Einaudi, 1982; Einaudi et al., 2003).
Even though the nearby Magma vein, containing both tennantite and enargite (Gustafson,
1961; Hammer and Peterson, 1968), is notably rich in arsenic, Resolution is relatively
arsenic-poor in spite of widespread, intense advanced argillic alteration (e.g., Manske and Paul,
2002), a distinction shared with Oyu Tolgoi (Khashgerel et al., 2008, 2009). The upper part of
the Resolution ore body is arsenic-bearing, but arsenic occurs most in solid solution in other
sulfides (e.g., arsenic-bearing pyrite) rather than as enargite.
The low arsenic contents of ores have metallurgical and environmental benefits to the
project, but geochemical controls on arsenic content and mineralogy are not well understood. An
elevated oxidation state of the fluid has been suggested as one possible cause (R. Beane, quoted
in Manske and Paul, 2002).
Relationship between silicate alteration types and sulfidation state of sulfides
Coexisting minerals, mainly the opaque sulfide and oxide minerals, can be used to
constrain the sulfidation state in which they formed (e.g., Barton, 1970; Barton and Skinner,
1967, 1979; Einaudi et al., 2003), and there is a long-recognized tendency for mineral
39
assemblages containing silicate minerals characteristic of advanced argillic alteration to contain
sulfide minerals characteristic of high and very high sulfidation states, because reactions
involving sulfur species that lead to higher sulfidation states also generate acid (e.g., Meyer and
Hemley, 1967; Einaudi, 1982).
At the Resolution deposit, most of the sericitic assemblages and all of the advanced
argillic assemblages contain high sulfidation state opaque assemblage (Table 5). There is no a
priori reason why coupled reactions involving sulfur species should cause the transition from
sericitic to advanced argillic to coincide precisely with the transition from intermediate to high
sulfidation states.
Resolution is thus an exception to the general “rule” that high sulfidation-state minerals
are deposited only during advanced argillic alteration, for which Chuquicamata is another
possible example. Advanced argillic alteration is not present (or at least not yet reported) at
exposed and drilled levels of Chuquicamata, in spite of the fact that high-sulfidation state sulfide
minerals, including enargite, are widespread and vertically extensive, seemingly cogenetic with
sericitic alteration (Ossandón et al., 2001).
Source of high copper grades
The search for genetic understanding of controls on metal grades are an enduring theme
of economic geology, and Resolution is distinctive for having high hypogene copper grades in a
variety of alteration types (Manske and Paul, 2002; Schwarz, 2007). Telescoping of
alteration-mineralization events is also offered as one possible explanation for porphyry deposits
40
with higher hypogene grades (e.g., Sillitoe, 2010). The compositions of certain host rocks, such
as carbonate rocks and diabase, also may have locally enhanced metal deposition (Fig. 4), but
many porphyry deposits in the region are hosted by identical units yet have half the grade of
Resolution, as noted by Manske and Paul (2002).
Although some of the highest grades in the Resolution deposit occur in areas of advanced
argillic alteration with abundant digenite (Figs. 4, 14) and superposition of later high-sulfidation
on earlier intermediate sulfidation assemblages locally increased copper grades and probably
added to the size of the ore body, the fact remains that areas of the deposit containing only
intermediate sulfidation assemblages also exhibit high hypogene grades (Figs. 4, 15). These
observations suggest that the principal control on high hypogene grades at Resolution may be
high fluxes of copper-bearing hydrothermal fluid, which would have been dictated by conditions
in the underlying magma chamber, rather than by conditions at the site of metal deposition.
Resolution offers considerable opportunity for future work to yield a better understanding
of whether or how hydrolytic alteration redistributed or added copper to the ore body.
Conclusions
Resolution is a geologically and economically significant example of porphyry copper
mineralization with extensive development of both advanced argillic alteration and
high-sulfidation state opaque assemblages. This study represents one of the few attempts to
determine mineral assemblages in areas of intense hydrolytic alteration and their relative ages.
41
The deposit is an exception to the general “rule” that high sulfidation-state minerals are
deposited only during advanced argillic alteration, as sericitic assemblages contain
high-sulfidation state opaque assemblages. Numerous advanced argillic assemblages are present;
most contain kaolinite or dickite, in contrast to deposits where andalusite and pyrophyllite are
much more common. Resolution is a relatively fluorine-rich deposit, and topaz, formed during
advanced argillic alteration, is abundant and predictably exhibits fluorine-poor compositions.
Acknowledgments
Support for this project was generously provided by Resolution Copper Mining LLC and
by Science Foundation Arizona through the UA Lowell Institute for Mineral Resources. We are
grateful for the opportunity to build on the work of Resolution geologists and earlier workers.
During the early stages of the project, Adam Schwarz provided invaluable assistance in geologic
logging, and Bill Hart provided invaluable aid by making the geologic and geochemical database
more useful to us. We thank Ken Domanik for technical assistance with electron microprobe
analyses. We acknowledge also benefitting, directly and indirectly over many years, from the
observations and insights on the geology of the Superior district from Geoff Ballantyne, Marco
Einaudi, Don Hammer, Kurt Friehauf, David Maher, Scott Manske, Tim Marsh, Alex Paul, and
Sandra Troutman.
42
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54
Tables
Table 1. Representative Electron Microprobe Analyses of Sheet Silicate Minerals
Table 2. Representative Electron Microprobe Analyses of Topaz and Zunyite
Table 3. Mineralogy of Veins and Matrix of Crosscutting Relationships
Table 4. Orientations of Common Vein Types Grouped by Assemblage
Table 5. Mineral Assemblages Produced by Acidic Fluids at Resolution
55
Figure Captions
Fig. 1. Location map. Map showing simplified surface geology of the Superior district, with
location of lines of cross section in this study, modified from Manske and Paul (2002). Inset map
shows location of Resolution deposit in state of Arizona.
Fig. 2 (top). Cross sections showing distribution of rock types, based on Resolution block model
of 2009. A. East-west cross section. B. North-south cross section.
Fig. 3 (bottom). Cross sections showing distribution of generalized alteration, based on
Resolution block model of 2009. A. East-west cross section. B. North-south cross section.
Fig. 4 (top). Cross sections showing distribution of copper, based on contouring of copper assays
from Resolution drill hole database. A. East-west cross section. B. North-south cross section.
Fig. 5 (bottom). Cross sections showing distribution of arsenic, based on contouring of arsenic
assays from Resolution drill hole database. A. East-west cross section. B. North-south cross
section.
Fig. 6. SEM images showing backscattered electron images of sulfide minerals (A, C, and E) and
corresponding distribution of arsenic (B, D, and F) from samples collected from sulfide-rich
56
portions of assay intervals containing relatively high levels of arsenic. A, B: R1A-1314,
chalcopyrite and chalcocite with pyrite. C, D: R3-1922, chalcopyrite and chalcocite with pyrite.
E, F: R3-1604, chalcocite and pyrite. Note uniform, low-level distribution of arsenic, indicating
presence of arsenic ion solid solution and lack of evidence for arsenic minerals such as tennantite
or enargite.
Fig. 7 (top). Cross sections showing distribution of iron, based on contouring of iron assays from
Resolution drill hole database. A. East-west cross section. B. North-south cross section.
Fig. 8 (bottom). Cross sections showing distribution of sulfur, based on contouring of sulfur
assays from Resolution drill hole database. A. East-west cross section. B. North-south cross
section.
Fig. 9 (top). Cross sections showing distribution of clay, including kaolinite and dickite. A.
East-west cross section. B. North-south cross section.
Fig. 10 (bottom). Cross sections showing distribution of sericite. A. East-west cross section. B.
North-south cross section.
Fig. 11 (top). Cross sections showing distribution of topaz. A. East-west cross section. B.
57
North-south cross section.
Fig. 12 (bottom). Cross sections showing distributions of alunite, pyrophyllite, and zunyite. A.
East-west cross section. B. North-south cross section.
Fig. 13. Cross sections showing distribution of pyrite. A. East-west cross section. B. North-south
cross section.
Fig. 14 (top). Cross sections showing distribution of bornite + chalcocite, where chalcocite also
includes digenite and similar phases. A. East-west cross section. B. North-south cross section.
Fig. 15 (bottom). Cross sections showing distribution of chalcopyrite. A. East-west cross section.
B. North-south cross section.
Fig. 16. Photomicrographs of selected textures of hydrothermal minerals. A. (Sample R1A-1261)
Rounded pyrite grains in contact with chalcopyrite being replaced by bornite and possibly pyrite.
B. (Sample R1A-1314) Chalcocite after bornite with pyrite grains. C. (Sample R5H-1670)
Chalcocite after bornite with pyrite clasts. D. (Sample R2A-1172) Advanced argillic alteration
front: clay on left, sericite on right. E. (Sample R2A-1207) Typical quartz + sericite + pyrite
assemblage; variations in grain size of sericite may be controlled by mineralogy or grain size of
58
original igneous minerals. F. (Sample R2A-1223) Alunite - clay vein; mainly alunite crystals
visible in photo. G. (Sample R13-1905) Fine-grained topaz with quartz surrounding bornite, with
(earlier?) quartz - sericite - pyrite assemblage on right. H. (Sample R13-1960) Quartz - sericite clay - pyrite assemblage. Note that sericite has replaced feldspar phenocrysts with clay present
mainly in the groundmass; this is a case where clay (probably kaolinite) and sericite appear to be
stable together, thus probably constituting a transitional advanced argillic-sericitic type of
assemblage.
Fig. 17. Photographs of selected hydrothermal vein types. Circles with notations in black ink are
locations of PIMA™ infrared spectrometer analyses. A. (Sample R2A-1223) Late stage dickite
vein with large envelope. Bornite mineralization surrounding. Arrow points to late dickite vein.
B. (Sample R3-1165) Dickite + quartz + topaz + pyrite > bornite vein with quartz clay pyrite
bornite filling and topaz envelope passing through sericitic alteration. C. (Sample R3-1175)
Thick quartz + kaolinite + pyrite + pyrophyllite + bornite cutting through quartz + sericite +
pyrite vein and sericitic wall rock. D. (Sample R3-1395) Quartz + kaolinite + dickite + topaz +
pyrite + bornite vein. Note orientation that is at low angle to core axis, as with most clay veins.
Circles show where the vein crosscuts a quartz + sericite + pyrite vein. E. (Sample R4-1624)
Extremely thick quartz + kaolinite + dickite + pyrite + bornite + chalcocite vein, and note low
angle to core axis. This region is relatively high in arsenic. F. (Sample R13-1915) Alunite and
bornite blebs with quartz + kaolinite + alunite + pyrite + bornite vein on right side of photo. G.
59
(Sample R13-1960) Kaolinite and alunite veins passing through sericitically altered rock. H.
(Sample R13-2027) Quartz + sericite + pyrite vein running parallel to quartz + dickite + pyrite +
bornite + chalcocite vein; in this case, relative ages are unclear.
Fig. 18. Photographs of selected crosscutting vein relationships , with veins paralleled by
double-pointed colored arrows for reference. Circles with notations in black ink are locations of
PIMA™ infrared spectrometer analyses. A. (Sample R3-1264) Alunite - clay hairline veinlet
(pink arrow) cutting quartz + sericite + pyrite vein (red), which is cut by thick quartz + kaolinite
+ dickite + pyrite vein (green). B. (Sample R3-1275) Alunite + kaolinite+ quartz + bornite
hairline veinlet (pink) cutting and offsetting quartz + sericite + pyrite veins (red). C. (Sample
R3-1313) Quartz + kaolinite + dickite + pyrite + bornite + chalcocite vein (green) cutting quartz
+ sericite + pyrite vein (blue). D. (Sample R3-1875) Quartz + sericite + pyrite vein (red) cut by
quartz + kaolinite + topaz + pyrite (yellow) and quartz + kaolinite + pyrite (green) veins. E.
(Sample R3-1917) Quartz + sericite + pyrite > chalcopyrite vein (blue) cutting quartz + sericite +
pyrite (pink) and quartz veins. F. (Sample R4-1885) Quartz + pyrite + kaolinite + dickite + topaz
vein (yellow) cutting quartz + sericite + pyrite (red) and other quartz veins. G. (Sample
R6D-1734) Quartz + dickite + pyrite hairline veinlet (green) cutting and offsetting quartz sericite
pyrite vein (red). H. (Sample R6D-1800) Quartz + kaolinite + dickite + pyrite + bornite vein
(green) cutting quartz + kaolinite + pyrite vein (green) cutting and offsetting two quartz + sericite
+ pyrite veins (red), which cut and offset an earlier quartz + sericite + pyrite vein (red).
60
Fig. 19. Photographs of selected hydrothermal mineral assemblages and associations. Circles
with notations in black ink are locations of PIMA™ infrared spectrometer analyses. A. (Sample
R1A-1261) Typical quartz + topaz + dickite + massive pyrite with high sulfidation copper
minerals. B. (Sample R2A-1283) Quartz + kaolinite + dickite + alunite + pyrite + bornite +
chalcocite vein passing heavily advanced argillic altered rock; PIMA™ determinations in wall
rock are 55% kaolinite + 45% alunite (center) and 48% dickite + 30% kaolinite + 23% alunite
(off right edge). C. (Sample R4-1863) High grade bornite and chalcocite in advanced argillic
altered breccia with PIMA™ determinations for dickite, kaolinite, and halloysite. D. (Sample
R5H-1761) Typical sericitically altered rock with high bornite + chalcocite grade and PIMA™
determination for muscovite. E. (Sample R5H-1830) Sericitically altered with dickite blebs, with
PIMA™ determination for dickite and muscovite. F. (Sample R13-1928) Planar topaz + zunyite
+ bornite + chalcocite + pyrite vein passing through (earlier?) sericitically altered rock. Circle on
bottom right is a PIMA™ determination for 63% zunyite + 37% topaz, whereas circles on top
right and left are 100% muscovite. G. (Sample R13-2060) Quartz + sericite + pyrite + bornite +
chalcocite assemblage with a PIMA™ determination of 100% muscovite. H. (Sample
R17C-1683) Late stage dickite vein with quartz + topaz + pyrite + chalcocite > bornite. Circle on
right is a PIMA™ determination for 76% halloysite + 15% topaz + 9% dickite.
Fig. 20. Possible evolutionary path of fluids at Resolution as a function of temperature and
61
acidity. Phase diagram based on Hemley and Jones (1964), Montoya and Hemley (1975), and
Hemley et al, (1980).
Fig. 21. Possible polythermal evolutionary path of fluids at Resolution on phase diagram
showing relative stability of topaz as a function of temperature. Diagram shows fields of stability
of andalusite (ANDAL), pyrophyllite (PYROPH), kaolinite (KAOL), sericite or muscovite
(MUSC), K-feldspar (KSPAR), and topaz (TOPAZ), with topaz field contoured for mole fraction
of fluor-topaz in topaz solid solution. Path follows labeled dots and passes into topaz field only
at low temperatures (solid dot) at ~300ºC, forming relatively fluorine-poor topaz (XF-Topaz ~ 0.6).
Based on Fig. 12 of Seedorff and Einaudi (2004b).
Fig. 22. Possible quasi-isothermal evolutionary path of fluids at Resolution on an
activity-activity diagram showing relative stability of topaz. See caption of Figure 21 for
abbreviations. Analogous to Fig. 9, but based on part of Fig. 12 of Seedorff and Einaudi, 2004b.
62
Figures
Winant et al. Figure 1
63
Winant et al. Figures 2 (top) and 3 (bottom)
64
Winant et al. Figures 4 (top) and 5 (bottom)
65
Winant et al. Figure 6
66
Winant et al. Figures 7 (top) and 8 (bottom)
67
Winant et al. Figures 9 (top) and 10 (bottom)
68
Winant et al. Figures 11 (top) and 12 (bottom)
69
Winant et al. Figure 13
70
Winant et al. Figures 14 (top) and 15 (bottom)
71
Winant et al. Figure 16
72
Winant et al. Figure 17
73
Winant et al. Figure 18
74
Winant et al. Figure 19
75
Winant et al. Figure 20
76
Winant et al. Figure 21
77
Winant et al. Figure 22
78
Appendix: Microprobe results.
79
Raw weight percent
Sample number
#1
#2
#3
#4
#5
#6
#7
#8
#9
#10
#11
#12
#13
#14
#15
#16
#17
#18
#19
#20
#21
#22
#23
#24
#25
#26
#27
#28
#30
#31
#32
#36
#37
#38
#40
#41
#42
#43
#44
#45
#46
#47
#29
4-1667
4-1667
4-1667
4-1667
4-1667
4-1667
4-1667
4-1667
4-1667
3-1917
3-1917
3-1917
3-1917
3-1917
3-1917
3-1917
1A-1347
1A-1347
1A-1347
1A-1347
1A-1347
6D-1862
6D-1862
6D-1862
6D-1862
6D-1862
6D-1862
6D-1862
3-1647
3-1647
3-1746B (1746.5)
3-1746B (1746.5)
3-1746B (1746.5)
3-1746B (1746.5)
3-1746B (1746.5)
3-1746B (1746.5)
3-1746B (1746.5)
3-1746B (1746.5)
13-1928
13-1928
13-1928
17C-1683
3-1647
Comments
F
ser
ser
clay
quartz
stilb fam?: high
ser
ser
ser
ser
biotite
biotite
biotite
sericite
sericite
apatite
biotite
clay
clay
clay
quartz
clay
ser
ser
ser
large grained m
clay on side of S
well formed mu
ser near edge
clay
clay
clay
topaz
topaz
mica
topaz
clay
topaz
topaz
topaz
zun
zun
clay
ser
Na
1.191
1.539
0.215
0.126
0.083
1.19
1.451
1.044
1.035
4.171
3.366
3.165
0.977
1.144
5.382
3.471
0.959
0.955
0.45
0
0.558
0.543
1.089
0.876
0.263
0.171
0.979
0.658
0.634
0.739
0.076
12.098
10.932
1.697
11.835
0.182
11.04
11.269
11.52
6.83
6.054
1.095
0.893
Mg
0.07
0.036
0.019
0.015
0.017
0.071
0.056
0.104
0.063
0.174
0.07
0.084
0.196
0.018
0.14
0.041
0
0
0.001
0
0.008
0.126
0.039
0.056
0.074
0.017
0.059
0.108
0.022
0.001
0.024
0.02
0
0.071
0.016
0.007
0.015
0.006
0
0.14
0.18
0.003
0.11
Al
0.864
0.761
0.095
0.005
0.172
0.802
1.374
0.967
0.646
11.379
10.546
9.92
1.39
1.498
0
11.203
0.012
0.003
0.006
0
0.013
0.787
1.675
1.115
0.301
0.015
0.918
0.742
0.133
0.033
0
0.014
0.081
1.3
0
0.007
0
0
0.01
0.01
0.005
0
0.587
18.13
20.002
19.785
0.032
3.501
19.262
18.181
18.161
19.662
7.746
9.194
9.224
16.276
17.03
0.019
8.8
20.898
20.219
21.525
0.057
20.871
18.273
16.775
17.33
19.862
21.038
18.123
19.057
19.711
20.601
20.925
28.728
29.182
17.568
29.365
20.892
29.473
28.342
30.53
29.74
30.472
20.615
19.245
Si
Cl
23.6
24.589
22.021
44.211
42.335
23.907
24.136
23.035
23.279
19.305
18.314
17.948
21.517
25.254
0.034
19.068
23.062
22.749
22.918
43.175
22.623
22.816
23.343
22.729
22.27
22.333
23.752
23.382
22.449
22.805
23.423
14.966
14.644
24.025
14.721
22.733
14.562
15.646
14.94
10.62
10.62
22.306
22.83
K
0.015
0.006
0.069
0.004
0.006
0.02
0
0.012
0.002
0.071
0.051
0.042
0.003
0.002
0.009
0.035
0.01
0.002
0.034
0
0
0.01
0.01
0.032
0.001
0.023
0.014
0.003
0.027
0
0
0.015
0.012
0
0.011
0.02
0
0.004
0
2.27
2.501
0.017
0.002
Ca
4.854
2.446
0.89
0.028
1.783
4.151
4.505
5.448
5.024
7.579
6.716
7.134
6.862
3.458
0.012
6.587
0.014
0.024
0.006
0
0
7.773
4.465
4.961
6.072
0.035
5.4
5.755
1.207
0.295
0.029
0.01
0.003
4.366
0.023
0.096
0.008
0.004
0.01
0
0
0.012
6.184
Sc
0
0.025
0.035
0.003
0
0
0.004
0.007
0
0.012
0.004
0.004
0.041
0.043
39.669
0
0.018
0.043
0.015
0.018
0.106
0.019
0
0
0.001
0.015
0
0.009
0.009
0.01
0.001
0.009
0.016
0
0
0.005
0.004
0
0
0
0
0.018
0.008
Ti
V
0.238
0.353
0.04
0.029
0.022
0.732
0.252
0.358
0.303
1.137
1.14
1.18
0.275
0.071
0
1.224
0.011
0.018
0.024
0.029
0.013
0.34
0.352
0.476
0.033
0
0.044
0
0.018
0.022
0.002
0
0.023
0.107
0
0
0.013
0
0
0.02
0
0
0.223
Cr
Mn
0.048
0
0.001
0
0
0
0.022
0
0
0.117
0.164
0.198
0.022
0.022
0.263
0.239
0
0
0.021
0.004
0.008
0
0
0.033
0
0
0
0.004
0
0
0
0.004
0.017
0.016
0.012
0
0.016
0.016
0
0
0.002
0.013
0.003
Fe
Cu
1.21
1.136
0.183
0
0.15
1.257
0.829
0.927
0.518
6.515
7.072
8.198
1.808
0.443
0.024
6.044
0.078
0.083
0.057
0.021
0.12
1.272
2.871
2.545
0.942
0.021
2.053
1.049
0.03
0.026
0.03
0.716
0.061
0.961
0.129
0
0.034
0.055
0.76
0
0.042
0.093
0.239
Zn
Moles
18.998
22.99
24.312
26.982
28.086
F
0.062691
0.081009
0.011317
0.006632
0.004369
0.062638
0.076376
0.054953
0.054479
0.219549
0.177177
0.166596
0.051426
0.060217
0.283293
0.182703
0.050479
0.050268
0.023687
0
0.029372
0.028582
0.057322
0.04611
0.013844
0.009001
0.051532
0.034635
0.033372
0.038899
0.004
0.636804
0.575429
0.089325
0.62296
0.00958
0.581114
0.593168
0.60638
0.359512
0.318665
0.057638
0.047005
Na
0.003045
0.001566
0.000826
0.000652
0.000739
0.003088
0.002436
0.004524
0.00274
0.007569
0.003045
0.003654
0.008525
0.000783
0.00609
0.001783
0
0
4.35E-05
0
0.000348
0.005481
0.001696
0.002436
0.003219
0.000739
0.002566
0.004698
0.000957
4.35E-05
0.001044
0.00087
0
0.003088
0.000696
0.000304
0.000652
0.000261
0
0.00609
0.007829
0.00013
0.004785
Mg
0.035538
0.031301
0.003908
0.000206
0.007075
0.032988
0.056515
0.039775
0.026571
0.46804
0.433778
0.408029
0.057173
0.061616
0
0.460801
0.000494
0.000123
0.000247
0
0.000535
0.032371
0.068896
0.045862
0.012381
0.000617
0.037759
0.03052
0.005471
0.001357
0
0.000576
0.003332
0.053472
0
0.000288
0
0
0.000411
0.000411
0.000206
0
0.024144
Al
0.671929
0.741309
0.733267
0.001186
0.129753
0.713883
0.67382
0.673078
0.728708
0.28708
0.340746
0.341858
0.603217
0.631162
0.000704
0.326143
0.774516
0.749351
0.797754
0.002113
0.773516
0.677229
0.621711
0.64228
0.73612
0.779705
0.67167
0.706286
0.730524
0.763509
0.775517
1.06471
1.081536
0.651101
1.088318
0.774294
1.092321
1.050404
1.131495
1.102216
1.129345
0.764028
0.713253
Si
0.840276
0.87549
0.784056
1.574129
1.507335
0.851207
0.859361
0.82016
0.828847
0.687353
0.652069
0.639037
0.766111
0.899167
0.001211
0.678915
0.821121
0.809977
0.815994
1.537243
0.80549
0.812362
0.831126
0.809264
0.792922
0.795165
0.845688
0.832514
0.799295
0.81197
0.833974
0.532863
0.521399
0.855408
0.52414
0.809407
0.518479
0.557075
0.531938
0.378124
0.378124
0.794204
0.81286
35.453
39.102
Cl
0.000423
0.000169
0.001946
0.000113
0.000169
0.000564
0
0.000338
5.64E-05
0.002003
0.001439
0.001185
8.46E-05
5.64E-05
0.000254
0.000987
0.000282
5.64E-05
0.000959
0
0
0.000282
0.000282
0.000903
2.82E-05
0.000649
0.000395
8.46E-05
0.000762
0
0
0.000423
0.000338
0
0.00031
0.000564
0
0.000113
0
0.064028
0.070544
0.00048
5.64E-05
K
0.124137
0.062554
0.022761
0.000716
0.045599
0.106158
0.115211
0.139328
0.128484
0.193826
0.171756
0.182446
0.17549
0.088435
0.000307
0.168457
0.000358
0.000614
0.000153
0
0
0.198788
0.114189
0.126873
0.155286
0.000895
0.1381
0.147179
0.030868
0.007544
0.000742
0.000256
7.67E-05
0.111657
0.000588
0.002455
0.000205
0.000102
0.000256
0
0
0.000307
0.15815
40.08
Ca
0
0.000624
0.000873
7.49E-05
0
0
9.98E-05
0.000175
0
0.000299
9.98E-05
9.98E-05
0.001023
0.001073
0.989746
0
0.000449
0.001073
0.000374
0.000449
0.002645
0.000474
0
0
2.5E-05
0.000374
0
0.000225
0.000225
0.00025
2.5E-05
0.000225
0.000399
0
0
0.000125
9.98E-05
0
0
0
0
0.000449
0.0002
44.956
Sc
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
47.9
Ti
V
0.004969
0.00737
0.000835
0.000605
0.000459
0.015282
0.005261
0.007474
0.006326
0.023737
0.0238
0.024635
0.005741
0.001482
0
0.025553
0.00023
0.000376
0.000501
0.000605
0.000271
0.007098
0.007349
0.009937
0.000689
0
0.000919
0
0.000376
0.000459
4.18E-05
0
0.00048
0.002234
0
0
0.000271
0
0
0.000418
0
0
0.004656
50.942
52.996
54.938
55.847
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Mn
0.000874
0
1.82E-05
0
0
0
0.0004
0
0
0.00213
0.002985
0.003604
0.0004
0.0004
0.004787
0.00435
0
0
0.000382
7.28E-05
0.000146
0
0
0.000601
0
0
0
7.28E-05
0
0
0
7.28E-05
0.000309
0.000291
0.000218
0
0.000291
0.000291
0
0
3.64E-05
0.000237
5.46E-05
Fe
0.021666
0.020341
0.003277
0
0.002686
0.022508
0.014844
0.016599
0.009275
0.116658
0.126632
0.146794
0.032374
0.007932
0.00043
0.108224
0.001397
0.001486
0.001021
0.000376
0.002149
0.022777
0.051408
0.045571
0.016868
0.000376
0.036761
0.018783
0.000537
0.000466
0.000537
0.012821
0.001092
0.017208
0.00231
0
0.000609
0.000985
0.013609
0
0.000752
0.001665
0.00428
Cr
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
63.546
Cu
65.37
Zn
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Optimum site occupancy
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
mica
mica
clay
qz
stilb?
mica
mica
mica
mica
mica
mica
mica
mica
mica
apatite
mica
clay
clay
clay
qz
clay
mica
mica
mica
mica
clay
mica
mica
clay
clay
clay
topaz
topaz
mica
topaz
clay
topaz
topaz
topaz
zun
zun
clay
mica
T + O = 6 -7
T + O = 6 -7
Si = 4
6.074
6.137
4
4
T+O
T+O
T+O
T+O
T+O
T+O
T+O
T+O
T+O
= 6 -7
= 6 -7
= 6 -7
= 6 -7
= 6 -7
= 6 -7
= 6 -7
= 6 -7
= 6 -7
6.107
6.088
6.07
6.084
6.56
6.66
6.66
6.061
6.088
T + O = 6 -7
Si = 4
Si = 4
Si = 4
6.65
4
4
4
4
4
6.036
6.168
6.138
6.108
4
6.098
6.091
4
4
4
3
3
6.064
3
4
3
3
3
18
18
4
6.042
Si = 4
T + O = 6 -7
T + O = 6 -7
T + O = 6 -7
T + O = 6 -7
Si = 4
T + O = 6 -7
T + O = 6 -7
Si = 4
Si = 4
Si = 4
T+O =3
T+O =3
T + O = 6 -7
T+O =3
Si = 4
T+O =3
T+O =3
T+O =3
T + O = 18
T + O = 18
Si = 4
T + O = 6 -7
Charge balance
Actual Cation Sum
Normalization factor
Sum of (-) charge
Sum of (+) charge (no Fe)
1.57525247
3.855889844
23.51327947
23.33718118
1.675810813
3.66210789
23.40543653
23.24812209
0.784056113
5.101675673
28
27.40900777
1.576126523
2.537867323
35.96576365
17.98268118
1.647307679
0
24
#DIV/0!
1.635867922
3.733186474
23.52810806
23.35242769
1.610200959
3.78089453
23.42245732
23.30627349
1.557085282
3.898309278
23.56891226
23.43379005
1.599727401
3.80314796
23.58518433
23.51306434
1.584998517
4.138805135
22.16607825
21.14769806
1.580008343
4.215167616
22.49421509
21.37131155
1.563956372
4.258430811
22.57103116
21.25681303
1.465017345
4.137152382
23.57378158
23.29292232
1.601759116
3.800821197
23.5418241
23.47921567
0.007131701
0
24
#DIV/0!
1.603987217
4.145918327
22.47686701
21.54035507
0.821120843
4.871390166
28
27.33431719
0.809976501
4.938414875
28
27.12409393
0.815993734
4.901998429
28
27.75239357
1.540409539
2.596712043
24
17.9925629
0.80549028
4.965919639
28
27.56379289
1.551836776
3.889584326
23.77546192
23.58961468
1.580489571
3.902588231
23.5503915
23.13291827
1.553515548
3.951038667
23.62850185
23.25212033
1.558979283
3.917948153
23.89130226
23.75342122
0.795164851
5.030403439
28
27.78488698
1.592797108
3.828485103
23.60239935
23.30818277
1.588176271
3.835216601
23.73368376
23.58347245
0.799295022
5.004409996
28
27.19131411
0.811970377
4.926288095
28
27.34605805
0.833974222
4.796311318
28
27.16846766
1.611042554
1.862148205
21.62677789
10.73576169
1.608147965
1.865499982
21.85181159
10.88819769
1.579713445
3.83867088
23.31421997
23.17724241
1.614986589
1.857600564
21.68442443
10.80496243
0.809406822
4.941890644
28
27.49714484
1.611971206
1.861075426
21.83700677
10.88196232
1.608754743
1.864796367
21.78730526
10.92710831
1.67745262
1.788426072
21.83106976
10.79357377
1.481169481
12.15255933
13.70581102
55.52216373
1.508463941
11.9326684
14.7113908
55.93134386
0.794203518
5.036492424
28
27.55317198
1.559247924
3.874945034
23.63527963
23.60086211
Hypothetical
10.811
Fe3+
0.009012265
0.008330444
0.016717221
0
#DIV/0!
0.007627824
0.003935659
0.005706743
0.001568999
0.052730624
0.055355943
0.063994631
0.012985558
0.002309257
#DIV/0!
0.039134095
0.006803739
0.007339489
0.005003204
0.000976435
0.010670409
0.008664895
0.016222277
0.016276463
0.005708956
0.001891569
0.01273754
0.006134012
0.002688279
0.002293471
0.002576492
0.023874122
0.00203763
0.004867955
0.004290839
0
0.001133034
0.001836514
0.024337992
0
0
0.00838709
0.00125148
Fe2+
0.074530749
0.066161553
0
0
#DIV/0!
0.076398451
0.052188422
0.059000988
0.033706498
0.430094155
0.478417857
0.561117117
0.120951296
0.027840326
#DIV/0!
0.40955483
0
0
0
0
0
0.079926278
0.184403196
0.163776063
0.060377086
0
0.128001979
0.065904633
0
0
0
0
0
0.061186851
0
0
0
0
0
0
0.00897402
0
0.015331539
Fe2+/Fe tot
0.892124256
0.888169949
0
#DIV/0!
#DIV/0!
0.909220967
0.929875754
0.911807396
0.955521572
0.890787246
0.896293256
0.897626895
0.903047163
0.923406661
#DIV/0!
0.912781233
0
0
0
0
0
0.902192343
0.919141487
0.909601585
0.913613289
0
0.90949564
0.914851091
0
0
0
0
0
0.926304307
0
#DIV/0!
0
0
0
#DIV/0!
1
0
0.924532458
B
6.939
Li
Calculated
18.015
H2 O
4.1035748
4.1880893
14.005302
7.0377233
#DIV/0!
4.2563415
4.0767845
4.1231948
4.2456339
2.3570752
2.6649762
2.7191428
3.8904583
4.1968536
#DIV/0!
2.6906439
14.335262
14.138425
14.478131
6.9376195
14.246343
4.3716077
4.0973002
4.1360935
4.4731201
14.237975
4.2377874
4.3845185
14.091842
14.277265
14.988012
3.9344886
4.4707031
3.888434
4.0838847
14.490091
4.4455045
4.3165979
4.6111386
-2.3326324
-1.9960811
13.784086
4.225193
Atomic parts per formula unit
H
Li
1.7566397
1.7027183
7.9323354
1.9828818
#DIV/0!
1.764054
1.7112287
1.7844561
1.7925922
1.0830391
1.2471075
1.2855156
1.7868908
1.770912
#DIV/0!
1.2384335
7.7527231
7.751475
7.8791867
2
7.8541434
1.887731
1.7751957
1.8142509
1.9456511
7.9514581
1.8011997
1.8668419
7.8291819
7.8083731
7.9808127
0.8133889
0.9259058
1.65711
0.8422122
7.9498691
0.9185034
0.8936526
0.9155349
-3.1470945
-2.6443046
7.7072934
1.8176398
B
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
F
0.241729
0.296662
0.057736
0.016832
0
0.23384
0.288771
0.214224
0.207193
0.908672
0.746829
0.70944
0.212759
0.228874
0
0.757474
0.245903
0.248246
0.116112
0
0.145857
0.111172
0.223703
0.182183
0.054238
0.045278
0.197288
0.132834
0.167007
0.191627
0.019187
1.185823
1.073463
0.34289
1.157211
0.047343
1.081497
1.106137
1.084465
4.368985
3.802525
0.290292
0.182142
Na
0.01174
0.005734
0.004216
0.001656
0
0.011529
0.00921
0.017635
0.010422
0.031325
0.012834
0.015559
0.035271
0.002976
0
0.007394
0
0
0.000213
0
0.001728
0.021317
0.00662
0.009624
0.012611
0.00372
0.009825
0.018017
0.004789
0.000214
0.005007
0.00162
0
0.011855
0.001293
0.001505
0.001214
0.000487
0
0.074004
0.093427
0.000657
0.01854
Mg
0.137031
0.114629
0.019935
0.000522
0
0.12315
0.213678
0.155054
0.101054
1.937128
1.828445
1.737563
0.236535
0.23419
0
1.910444
0.002404
0.000609
0.00121
0
0.002655
0.125909
0.268873
0.181203
0.048507
0.003104
0.14456
0.11705
0.027377
0.006687
0
0.001072
0.006215
0.20526
0
0.001423
0
0
0.000736
0.004999
0.002454
0
0.093558
Al
2.590886
2.714754
3.740888
0.00301
0
2.66506
2.547641
2.623868
2.771384
1.188169
1.4363
1.455777
2.4956
2.398932
0
1.352164
3.772971
3.700608
3.910589
0.005486
3.841217
2.63414
2.426281
2.537673
2.884081
3.922231
2.571479
2.708759
3.655842
3.761265
3.719621
1.982647
2.017605
2.499361
2.02166
3.826476
2.032891
1.95879
2.023595
13.39475
13.47611
3.848021
2.763817
Si
3.240013
3.206137
4
3.994932
0
3.177714
3.249152
3.197235
3.152228
2.844821
2.748579
2.721296
3.169519
3.417572
0
2.814725
4
4
4
3.991777
4
3.159751
3.243542
3.197435
3.106626
4
3.237705
3.192873
4
4
4
0.992271
0.972669
3.283631
0.973643
4
0.964928
1.038831
0.951331
4.595178
4.512032
4
3.14979
Cl
0.001631
0.00062
0.009929
0.000286
0
0.002106
0
0.001319
0.000215
0.008289
0.006064
0.005045
0.00035
0.000214
0
0.004093
0.001374
0.000279
0.004701
0
0
0.001097
0.001101
0.003566
0.000111
0.003263
0.001512
0.000325
0.003811
0
0
0.000788
0.000631
0
0.000576
0.002788
0
0.00021
0
0.778109
0.841779
0.002415
0.000219
K
0.478658
0.229081
0.116119
0.001817
0
0.396309
0.435603
0.543143
0.488645
0.80221
0.72398
0.776933
0.726028
0.336127
0
0.698408
0.001744
0.003031
0.000752
0
0
0.773202
0.445631
0.501281
0.608403
0.004503
0.528715
0.564464
0.154476
0.037166
0.003557
0.000476
0.000143
0.428613
0.001093
0.012133
0.000381
0.000191
0.000457
0
0
0.001546
0.612824
Ca
0
0.002284
0.004455
0.00019
0
0
0.000377
0.000681
0
0.001239
0.000421
0.000425
0.004232
0.004078
0
0
0.002188
0.005298
0.001835
0.001166
0.013133
0.001844
0
0
9.78E-05
0.001883
0
0.000861
0.001124
0.001229
0.00012
0.000418
0.000745
0
0
0.000617
0.000186
0
0
0
0
0.002262
0.000773
Sc
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Ti
V
0.019159
0.026988
0.00426
0.001536
0
0.05705
0.019891
0.029136
0.024057
0.098243
0.100319
0.104905
0.023752
0.005634
0
0.105942
0.001119
0.001856
0.002456
0.001572
0.001348
0.027609
0.028679
0.039263
0.002699
0
0.003517
0
0.001881
0.002263
0.0002
0
0.000896
0.008575
0
0
0.000505
0
0
0.005074
0
0
0.01804
Cr
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Mn
0.003369
0
9.29E-05
0
0
0
0.001514
0
0
0.008814
0.012583
0.015348
0.001657
0.001522
0
0.018036
0
0
0.001874
0.000189
0.000723
0
0
0.002373
0
0
0
0.000279
0
0
0
0.000136
0.000577
0.001118
0.000406
0
0.000542
0.000543
0
0
0.000434
0.001192
0.000212
Fe
Cu
0.083543
0.074492
0.016717
0
0
0.084026
0.056124
0.064708
0.035275
0.482825
0.533774
0.625112
0.133937
0.03015
0
0.448689
0.006804
0.007339
0.005003
0.000976
0.01067
0.088591
0.200625
0.180053
0.066086
0.001892
0.14074
0.072039
0.002688
0.002293
0.002576
0.023874
0.002038
0.066055
0.004291
0
0.001133
0.001837
0.024338
0
0.008974
0.008387
0.016583
Zn
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
IV
Si
B
3.240013
3.206137
4
3.994932
0
3.177714
3.249152
3.197235
3.152228
2.844821
2.748579
2.721296
3.169519
3.417572
0
2.814725
4
4
4
3.991777
4
3.159751
3.243542
3.197435
3.106626
4
3.237705
3.192873
4
4
4
0.992271
0.972669
3.283631
0.973643
4
0.964928
1.038831
0.951331
4.595178
4.512032
4
3.14979
Oct
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Al
Sum
0.759987
4
0.793863
4
0
4
0.005068
4
4
4
0.822286
4
0.750848
4
0.802765
4
0.847772
4
1.155179
4
1.251421
4
1.278704
4
0.830481
4
0.582428
4
4
4
1.185275
4
0
4
0
4
0
4
0.008223
4
4.44E-16
4
0.840249
4
0.756458
4
0.802565
4
0.893374
4
0
4
0.762295
4
0.807127
4
0
4
0
4
0
4
3.007729
4
3.027331
4
0.716369
4
3.026357
4
0
4
3.035072
4
2.961169
4
3.048669
4
0 4.595178
0 4.512032
4.44E-16
4
0.85021
4
Al
1.830899
1.920891
3.740888
-0.002058
-4
1.842774
1.796792
1.821103
1.923613
0.03299
0.184879
0.177073
1.665119
1.816504
-4
0.166889
3.772971
3.700608
3.910589
-0.002738
3.841217
1.793891
1.669823
1.735108
1.990708
3.922231
1.809183
1.901632
3.655842
3.761265
3.719621
-1.025082
-1.009726
1.782993
-1.004697
3.826476
-1.00218
-1.00238
-1.025074
13.39475
13.47611
3.848021
1.913607
Mg
Fe 2+
Fe 3+
0.137031 0.0745 0.00901
0.114629 0.0662 0.00833
0.019935
0 0.01672
0.000522
0
0
0 #DIV/0! #DIV/0!
0.12315 0.0764 0.00763
0.213678 0.0522 0.00394
0.155054
0.059 0.00571
0.101054 0.0337 0.00157
1.937128 0.4301 0.05273
1.828445 0.4784 0.05536
1.737563 0.5611 0.06399
0.236535
0.121 0.01299
0.23419 0.0278 0.00231
0 #DIV/0! #DIV/0!
1.910444 0.4096 0.03913
0.002404
0 0.0068
0.000609
0 0.00734
0.00121
0
0.005
0
0 0.00098
0.002655
0 0.01067
0.125909 0.0799 0.00866
0.268873 0.1844 0.01622
0.181203 0.1638 0.01628
0.048507 0.0604 0.00571
0.003104
0 0.00189
0.14456
0.128 0.01274
0.11705 0.0659 0.00613
0.027377
0 0.00269
0.006687
0 0.00229
0
0 0.00258
0.001072
0 0.02387
0.006215
0 0.00204
0.20526 0.0612 0.00487
0
0 0.00429
0.001423
0
0
0
0 0.00113
0
0 0.00184
0.000736
0 0.02434
0.004999
0
0
0.002454
0.009
0
0
0 0.00839
0.093558 0.0153 0.00125
X
Mn
0.003369
0
9.29E-05
0
0
0
0.001514
0
0
0.008814
0.012583
0.015348
0.001657
0.001522
0
0.018036
0
0
0.001874
0.000189
0.000723
0
0
0.002373
0
0
0
0.000279
0
0
0
0.000136
0.000577
0.001118
0.000406
0
0.000542
0.000543
0
0
0.000434
0.001192
0.000212
Ti
0.019159
0.026988
0.00426
0.001536
0
0.05705
0.019891
0.029136
0.024057
0.098243
0.100319
0.104905
0.023752
0.005634
0
0.105942
0.001119
0.001856
0.002456
0.001572
0.001348
0.027609
0.028679
0.039263
0.002699
0
0.003517
0
0.001881
0.002263
0.0002
0
0.000896
0.008575
0
0
0.000505
0
0
0.005074
0
0
0.01804
[]
0.926
0.863
0.218106
3
#DIV/0!
0.893
0.912
0.93
0.916
0.44
0.34
0.34
0.939
0.912
#DIV/0!
0.35
0.216702
0.289587
0.078868
3
0.143387
0.964
0.832
0.862
0.892
0.072774
0.902
0.909
0.312212
0.227492
0.277602
4
4
0.936
4
0.172101
4
4
4
0
0
0.142401
0.958
Sum
3
3
4
3
#DIV/0!
3
3
3
3
3
3
3
3
3
#DIV/0!
3
4
4
4
3
4
3
3
3
3
4
3
3
4
4
4
3
3
3
3
4
3
3
3
13.40482
13.48797
4
3
Na
0.01174
0.005734
0.004216
0.001656
0
0.011529
0.00921
0.017635
0.010422
0.031325
0.012834
0.015559
0.035271
0.002976
0
0.007394
0
0
0.000213
0
0.001728
0.021317
0.00662
0.009624
0.012611
0.00372
0.009825
0.018017
0.004789
0.000214
0.005007
0.00162
0
0.011855
0.001293
0.001505
0.001214
0.000487
0
0.074004
0.093427
0.000657
0.01854
K
Ca []
Sum
0.48
0 0.509601
0.23
0 0.762901
0.12
0
0
0 0.996337
0
0
1
0.4
0 0.592162
0.44
0 0.55481
0.54
0 0.438541
0.49
0 0.500933
0.8
0 0.165227
0.72
0 0.262765
0.78
0 0.207082
0.73
0 0.234469
0.34
0 0.656819
0
0
1
0.7
0 0.294198
0
0 0.996068
0 0.01 0.991671
0
0
0.9972
0
0 0.998834
0 0.01 0.985139
0.77
0 0.203637
0.45
0 0.547749
0.5
0 0.489095
0.61
0 0.378888
0
0 0.989895
0.53
0 0.46146
0.56
0 0.416658
0.15
0 0.839611
0.04
0 0.961391
0
0 0.991316
0
0 0.997486
0
0 0.999112
0.43
0 0.559532
0
0 0.997615
0.01
0 0.985746
0
0 0.998219
0
0 0.999323
0
0 0.999543
0
0 0.925996
0
0 0.906573
0
0 0.995535
0.61
0 0.367862
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
OH
F
0.241729
0.296662
0.057736
0.016832
0
0.23384
0.288771
0.214224
0.207193
0.908672
0.746829
0.70944
0.212759
0.228874
0
0.757474
0.245903
0.248246
0.116112
0
0.145857
0.111172
0.223703
0.182183
0.054238
0.045278
0.197288
0.132834
0.167007
0.191627
0.019187
1.185823
1.073463
0.34289
1.157211
0.047343
1.081497
1.106137
1.084465
4.368985
3.802525
0.290292
0.182142
Oxide weight percent
Cl
0.001631
0.00062
0.009929
0.000286
0
0.002106
0
0.001319
0.000215
0.008289
0.006064
0.005045
0.00035
0.000214
0
0.004093
0.001374
0.000279
0.004701
0
0
0.001097
0.001101
0.003566
0.000111
0.003263
0.001512
0.000325
0.003811
0
0
0.000788
0.000631
0
0.000576
0.002788
0
0.00021
0
0.778109
0.841779
0.002415
0.000219
OH
Sum
1.75664
1.702718
7.932335
1.982882
2
1.764054
1.711229
1.784456
1.792592
1.083039
1.247108
1.285516
1.786891
1.770912
2
1.238434
7.752723
7.751475
7.879187
2
7.854143
1.887731
1.775196
1.814251
1.945651
7.951458
1.8012
1.866842
7.829182
7.808373
7.980813
0.813389
0.925906
1.65711
0.842212
7.949869
0.918503
0.893653
0.915535
-3.14709
-2.6443
7.707293
1.81764
2
2
8
2
2
2
2
2
2
2
2
2
2
2
2
2
8
8
8
2
8
2
2
2
2
8
2
2
8
8
8
2
2
2
2
8
2
2
2
2
2
8
2
SiO2
50.48884
52.60467
47.1108
94.58314
90.56971
51.14562
51.63554
49.2801
49.80211
41.3003
39.1802
38.39719
46.03256
54.02734
0.072738
40.79327
49.33787
48.66825
49.0298
92.36677
48.39869
48.81158
49.93903
48.62546
47.6435
47.77828
50.81402
50.02246
48.02644
48.78805
50.11018
32.01763
31.32875
51.39807
31.49348
48.63402
31.15333
33.47239
31.962
22.71998
22.71998
47.72051
48.84154
TiO2
0.396998
0.588825
0.066722
0.048374
0.036697
1.221019
0.420351
0.597165
0.505422
1.896582
1.901587
1.968309
0.458716
0.118432
0
2.041704
0.018349
0.030025
0.040033
0.048374
0.021685
0.56714
0.587157
0.793996
0.055046
0
0.073395
0
0.030025
0.036697
0.003336
0
0.038365
0.178482
0
0
0.021685
0
0
0.033361
0
0
0.371977
Al2O3
34.25631
37.79342
37.3834
0.060463
6.615076
36.3952
34.35267
34.31488
37.15099
14.63593
17.3719
17.42858
30.75321
32.17788
0.0359
16.62744
39.48639
38.20343
40.6711
0.1077
39.43538
34.5265
31.69606
32.74472
37.52889
39.75092
34.24308
36.00786
37.24358
38.92522
39.53741
54.28104
55.13886
33.19442
55.48464
39.47506
55.6887
53.5517
57.68588
56.19319
57.57629
38.95167
36.36308
Fe2O3
0.186624
0.181633
0.261643
#DIV/0!
#DIV/0!
0.163147
0.083115
0.116888
0.032941
1.017294
1.048596
1.199921
0.250621
0.048512
#DIV/0!
0.753691
0.11152
0.118669
0.081495
0.030025
0.171569
0.177877
0.331908
0.328933
0.116347
0.030025
0.265655
0.127707
0.042892
0.037173
0.042892
1.023698
0.087214
0.101257
0.184437
#DIV/0!
0.048611
0.078636
1.086607
#DIV/0!
0
0.132966
0.025788
FeO
1.388735
1.298025
0
#DIV/0!
#DIV/0!
1.470326
0.991718
1.087406
0.636765
7.466158
8.154572
9.467004
2.100476
0.526266
#DIV/0!
7.097411
0
0
0
0
0
1.476369
3.394879
2.978158
1.10719
0
2.40214
1.234624
0
0
0
0
0
1.145212
0
#DIV/0!
0
0
0
#DIV/0!
0.054033
0
0.284269
MgO
1.432608
1.261823
0.157521
0.008291
0.285195
1.329805
2.278245
1.603394
1.07114
18.86765
17.48644
16.44846
2.304775
2.483851
0
18.57582
0.019897
0.004974
0.009949
0
0.021555
1.304934
2.777336
1.848794
0.499091
0.024872
1.522146
1.230319
0.220529
0.054718
0
0.023214
0.134307
2.155545
0
0.011607
0
0
0.016581
0.016581
0.008291
0
0.973311
MnO
0.061979
0
0.001291
0
0
0
0.028407
0
0
0.151075
0.211763
0.255665
0.028407
0.028407
0.339595
0.308606
0
0
0.027116
0.005165
0.01033
0
0
0.042611
0
0
0
0.005165
0
0
0
0.005165
0.021951
0.02066
0.015495
0
0.02066
0.02066
0
0
0.002582
0.016786
0.003874
CaO
0
0.03498
0.048972
0.004198
0
0
0.005597
0.009794
0
0.01679
0.005597
0.005597
0.057367
0.060166
55.50493
0
0.025186
0.060166
0.020988
0.025186
0.148315
0.026585
0
0
0.001399
0.020988
0
0.012593
0.012593
0.013992
0.001399
0.012593
0.022387
0
0
0.006996
0.005597
0
0
0
0
0.025186
0.011194
Na2O
0.094358
0.048527
0.025612
0.02022
0.022916
0.095706
0.075487
0.14019
0.084923
0.234548
0.094358
0.11323
0.264204
0.024264
0.188717
0.055267
0
0
0.001348
0
0.010784
0.169845
0.052571
0.075487
0.09975
0.022916
0.079531
0.145582
0.029656
0.001348
0.032351
0.02696
0
0.095706
0.021568
0.009436
0.02022
0.008088
0
0.188717
0.242636
0.004044
0.148278
K2O
5.847095
2.946435
1.072088
0.033729
2.14779
5.000266
5.426692
6.562623
6.051876
9.129611
8.090047
8.593567
8.265918
4.165483
0.014455
7.934655
0.016864
0.02891
0.007228
0
0
9.363302
5.378508
5.975986
7.314289
0.042161
6.504803
6.932433
1.453944
0.355355
0.034933
0.012046
0.003614
5.259254
0.027706
0.115641
0.009637
0.004818
0.012046
0
0
0.014455
7.449204
H2O
F
Cl
4.103575
1.191
4.188089
1.539
14.0053
0.215
7.037723
0.126
#DIV/0!
0.083
4.256342
1.19
4.076784
1.451
4.123195
1.044
4.245634
1.035
2.357075
4.171
2.664976
3.366
2.719143
3.165
3.890458
0.977
4.196854
1.144
#DIV/0!
5.382
2.690644
3.471
14.33526
0.959
14.13843
0.955
14.47813
0.45
6.937619
0
14.24634
0.558
4.371608
0.543
4.0973
1.089
4.136093
0.876
4.47312
0.263
14.23798
0.171
4.237787
0.979
4.384519
0.658
14.09184
0.634
14.27727
0.739
14.98801
0.076
3.934489
12.098
4.470703
10.932
3.888434
1.697
4.083885
11.835
14.49009
0.182
4.445505
11.04
4.316598
11.269
4.611139
11.52
-2.33263
6.83
-1.99608
6.054
13.78409
1.095
4.225193
0.893
0.015
0.006
0.069
0.004
0.006
0.02
0
0.012
0.002
0.071
0.051
0.042
0.003
0.002
0.009
0.035
0.01
0.002
0.034
0
0
0.01
0.01
0.032
0.001
0.023
0.014
0.003
0.027
0
0
0.015
0.012
0
0.011
0.02
0
0.004
0
2.27
2.501
0.017
0.002
Subtotal
99.46312
102.4914
100.4173
#DIV/0!
#DIV/0!
102.2874
100.8256
98.89164
100.6188
101.315
99.62703
99.80367
95.38671
99.00345
#DIV/0!
100.3845
104.3203
102.2099
104.8512
99.52084
103.0226
101.3487
99.35374
98.45824
99.10262
102.1021
101.1356
100.7643
101.8125
103.2288
104.8265
103.4498
102.1902
99.13404
103.1572
#DIV/0!
102.4539
102.7259
106.8943
#DIV/0!
87.16273
101.7617
99.5927
O=F+Cl
-0.50491
-0.64942
-0.10611
-0.05396
-0.0363
-0.50562
-0.61101
-0.44233
-0.43629
-1.77242
-1.42892
-1.34225
-0.41209
-0.48219
-2.26837
-1.46953
-0.40609
-0.4026
-0.19717
0
-0.23497
-0.23091
-0.46083
-0.3761
-0.11097
-0.0772
-0.41541
-0.27776
-0.27307
-0.31119
-0.032
-5.09782
-4.60614
-0.7146
-4.98616
-0.08115
-4.64891
-4.74624
-4.85104
-3.38832
-3.11367
-0.46494
-0.37649
Total
98.95821
101.842
100.3112
#DIV/0!
#DIV/0!
101.7818
100.2146
98.44931
100.1825
99.54259
98.19811
98.46142
94.97462
98.52126
#DIV/0!
98.91498
103.9142
101.8073
104.654
99.52084
102.7877
101.1178
98.89291
98.08214
98.99164
102.0249
100.7201
100.4865
101.5394
102.9176
104.7945
98.35201
97.58402
98.41943
98.17105
#DIV/0!
97.80503
97.97964
102.0432
#DIV/0!
84.04906
101.2968
99.21621
Table 1. Representative Electron Microprobe Analyses of Sheet Silicate Minerals
Sample no. 1
4-1667 #1
2
3-1917 #14
Ser - Py - Qz
Mineral assemblage
Ser - Qz - Cp
illite3
Mineral
6D-1862 #25
3-1647 #29
Qz - Cl - Py - Bn - Cc
illite4
muscovite5
3-1917 #10
3-1917 #16
Qz - Ser
Bio - Qz
sericite6
biotite (phlogopiteannite series)7
Py - Bio - Qz - Cp Anh
biotite (phlogopiteannite series)8
4-1667 #3
17C-1683 #47
Dk - Qz - Py
Qz - Hall - Dk - Tp - Py
- Cc - Bn
kaolinite group clay9
kaolinite group clay10
SiO2
50.49
54.03
47.64
48.84
41.30
40.79
47.11
TiO2
0.40
0.12
0.06
0.37
1.90
2.04
0.07
0.00
Al2O3
34.26
32.18
37.53
36.36
14.64
16.63
37.38
38.95
47.72
Fe2O3* 11
0.19
0.05
0.12
0.03
1.02
0.75
0.26
0.13
FeO* 11
1.39
0.53
1.11
0.28
7.47
7.10
0.00
0.00
MgO
1.43
2.48
0.50
0.97
18.87
18.58
0.16
0.00
MnO
0.06
0.03
0.00
0.00
0.15
0.31
0.00
0.02
CaO
0.00
0.06
0.00
0.01
0.02
0.00
0.05
0.03
Na2O
0.09
0.02
0.10
0.15
0.23
0.06
0.03
0.00
K2O
5.85
4.17
7.31
7.45
9.13
7.93
1.07
0.01
H2O*
4.10
4.20
4.47
4.23
2.36
2.69
14.01
13.78
F
1.19
1.14
0.26
0.89
4.17
3.47
0.22
1.10
Cl
0.02
0.00
0.00
0.00
0.07
0.04
0.07
0.02
99.46
99.00
99.10
99.59
101.32
100.38
100.42
101.76
Subtotal
O=(F+Cl)
-0.50
-0.48
-0.11
-0.38
-1.77
-1.47
-0.11
-0.46
Total
98.96
98.52
98.99
99.22
99.54
98.91
100.31
101.30
3.24
3.42
3.11
3.15
2.84
2.81
4.00
4.00
AlIV
0.76
0.58
0.89
0.85
1.16
1.19
0.00
0.00
Σ IV
4.00
4.00
4.00
4.00
4.00
4.00
4.00
4.00
Number of moles on basis of Σ IV + VI cations is >6 and <711
Si
IV
Al VI
VI
A
1.83
1.82
1.99
1.91
0.03
0.17
3.74
3.85
Mg
0.14
0.23
0.05
0.09
1.94
1.91
0.02
0.00
Fe2+
0.07
0.03
0.06
0.02
0.43
0.41
0.00
0.00
Fe3+
0.01
0.00
0.01
0.00
0.05
0.04
0.02
0.01
Mn
0.00
0.00
0.00
0.00
0.01
0.02
0.00
0.00
Ti
0.02
0.01
0.00
0.02
0.10
0.11
0.00
0.00
Σ VI
2.07
2.09
2.11
2.04
2.56
2.65
3.78
3.86
[]
0.93
0.91
0.89
0.96
0.44
0.35
0.22
0.14
Total
3.00
3.00
3.00
3.00
3.00
3.00
4.00
4.00
Na
0.01
0.00
0.01
0.02
0.03
0.01
0.00
0.00
K
0.48
0.34
0.61
0.61
0.80
0.70
0.12
0.00
Ca
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
ΣA
0.49
0.34
0.62
0.63
0.83
0.71
0.12
0.00
[]
0.51
0.66
0.38
0.37
0.17
0.29
0.88
1.00
Total
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
F
0.24
0.23
0.05
0.18
0.91
0.76
0.06
0.29
Cl
0.00
0.00
0.00
0.00
0.01
0.00
0.01
0.00
OH*
1.76
1.77
1.95
1.82
1.08
1.24
7.93
7.71
Analyses by A. Winant; oxides are reported in weight percent
1
Key to sample numbers: drill hole number-footage from collar of hole-# grain number
2
Abbreviations: anh = anhydrite; bio = biotite; bn = bornite; cc = chalcocite; cl = clay; cp = chalcopyrite; dk = dickite; hall = halloysite; py = pyrite; qz = quartz; ser = sericite; tp = topaz
3
Alteration envelope: fine-grained sericite intermixed with clay and fine-grained quartz and pyrite
4
Alteration envelope
5
Vein, with bornite-chalcocite replacing chalcopyrite
6
Alteration envelope: fine-grained sericite
7
Alteration envelope
8
Vein cutting quartz-chacopyrite-sericite vein
9
Clay alteration envelope near quartz veinlet
10
Thick chalcocite-bornite vein, within vein filling jadjacent to chalcocite-bornite
11
Assume hydroxyl site is filled with OH, F, or Cl; optimized to charge balance = 0 and FeIII/(FeII + FeIII) = 0.1
Table 2. Representative Electron Microprobe Analyses of Topaz and Zunyite
1
Sample no.
Mineral
assemblage2
Mineral
3-1746B #36
3-1746B (1746.5) #40
13-1928 #45
13-1928 #46
Tp-Zun-Cl-Qz-Py-Cc-Bn
Tp-Zun-Cl-Qz-Py-Cc
Tp-Zun-Py-Cc
Tp-Zun-Py-Cc
3
4
topaz
5
topaz
zunyite6
zunyite
SiO2
32.02
31.49
22.72
TiO2
0.00
0.00
0.03
0.00
Al2O3
54.28
55.48
56.19
57.58
22.72
Fe2O3*
1.02
0.18
0.00
0.00
FeO*
0.00
0.00
0.00
0.01
MgO
0.02
0.00
0.02
0.01
MnO
0.01
0.02
0.00
0.00
CaO
0.01
0.00
0.00
0.00
Na2O
0.03
0.02
0.19
0.24
K2O
0.01
0.03
0.00
0.00
H2O*
3.94
4.09
10.33
10.91
F
12.10
11.84
6.83
6.05
Cl
0.02
0.01
2.27
2.50
100.03
Subtotal
103.46
103.16
98.58
O=F
-5.10
-4.99
-3.39
-3.11
Total
98.36
98.18
95.19
96.91
Number of moles on basis of
Basis of Σ cations = 18
Σ IV + VI cations = 3
IV
VI
X
Si
0.99
0.97
4.58
4.49
Al
0.01
0.03
0.42
0.51
Σ IV
1.00
1.00
5.00
5.00
Al
1.97
1.99
12.92
12.90
Mg
0.00
0.00
0.00
0.00
Fe2+
0.00
0.00
0.00
0.01
Fe 3+
0.02
0.00
0.00
0.00
Mn
0.00
0.00
0.00
0.00
Ti
0.00
0.00
0.01
0.00
Σ VI
2.00
2.00
12.93
12.91
Na
0.00
0.00
0.07
0.09
4.35
3.78
F
1.18
1.16
Cl
0.00
0.00
0.77
0.84
OH*
0.81
0.84
13.87
14.38
0.59
0.58
X F-Topaz7
Analyses by A. Winant; oxides are reported in weight percent; all Fe in topaz assumed to be FeIII
1
Key to sample numbers: drill hole number-footage from collar of hole-# grain number
2
3
Abbreviations: bn = bornite; cc = chalcocite; cl = clay; py = pyrite; qz = quartz; tp = topaz; zun = zunyite
Inclusion in pyrite + bornite
4
Inclusion in chalcocite
5
Rimming chalcocite (after pyrite)
6
Rimming chalcocite (after pyrite)
7
X F-Topaz , mole fraction fluor-topaz in topaz solid solution, F / (F + OH*).
Table 3. Mineralogy of Veins and Matrix of Crosscutting Relationships
Assemblage of Offsetting Vein (Younger)
Assem
Silicate
Alteration
Type1
Silicate
Alteration
Type1
Potassic or
none
Potassic or none
Sericitic
Mineralogy
qz - bio qz - moly py > cp
of vein2,3
qz - moly
1
qz - ser py
qz - ser py - cp
qz - ser py - bn cc
4
2
1
5
Transitional advanced argillic-sericitic
qz - ser qz - ser - py - clay - qz - ser qz - ser - py - clay - alun - bn - py - alun py - clay bn
cc
bn - cc
1
Uncertain
qz - py bn - cc
Advanced argillic
cp - bn cc > tp
qz - clay qz - clay - qz - clay qz - clay py - alun qz - clay - py - tp ± zun - py - qz - clay - py - bn bn - cc
alun - clay py - tp
bn ± cc
bn
py
cc
qz - clay
1
4
2
6
12
4
38
4
5
2
qz - bio py > cp
Sericitic
qz - ser - py
qz - ser - py
- cp
1
2
1
2
7
3
1
qz - ser - py
- bn - cc
Transitional qz - ser - py
- clay
advanced
argillicsericitic
2
qz - ser - py
- clay - bn
1
1
1
1
1
qz - ser - py
- clay - alun
- bn - cc
qz - ser - py
- alun - bn cc
Uncertain
qz - py - bn cc
cp - bn - cc
> tp
Advanced
argillic
1
qz - clay py - alun bn - cc
2
alun - clay
qz - clay py - tp
1
qz - clay py - tp ± bn
± cc
qz - clay zun - py bn
qz - clay py
qz - clay py - bn - cc
qz - clay
1
2
3
3
1
1
1
2
6
1
clay
1
1
1
Based on criteria of Seedorff et al. (2005a)
Vein filling and alteration envelope are not necessarily distinct, so vein minerals listed include vein filling and envelope (if present); diagonal boxes (patterned )are offsets between similar veins; tallies below the diagonal may represent reversals (see text)
Abbreviations: alun = alunite; bio = biotite; bn = bornite; cc = chalcocite; cl = clay; cp = chalcopyrite;moly = molybdenite; py = pyrite; qz = quartz; ser = sericite; tp = topaz; zun = zunyite
clay
1
Table 4. Widths and Orientations of Common Vein Types Grouped by Assemblage
Assemblage
(abbreviated) 1
Alteration Type of
Silicate Minerals2
Widths3 (mm)
Orientations
sericite-chalcocitebornite
Sericitic
0.5 - 5 // 0.25 - 6
At variable angles to core
axis (0-90 deg).
pyrophyllite-clay
Advanced argillic
10 - 40 // 5 - 50
alunite-clay
Advanced argillic
0.1 - 6 // 0 - 2
Frequently at low angles to
core axis (0-30 deg).
clay-topaz-zunyite
Advanced argillic
5 - 50 // 2 - 35
Frequently at low angles to
core axis (0-30 deg).
clay
Advanced argillic
2 - >100 // 1 - 40
Frequently at low angles to
core axis (0-30 deg).
1
2
3
Comments
Very rare (two
occurrences
logged)
See Table 5 for definitions of assemblages and their abbreviations
Based on criteria of Seedorff et al. (2005a); see also Table 5
Widths of zones are shown where distinct, with width of vein filling followed by two slashes and width
of alteration envelope
Table 5. Mineral Assemblages Produced by Acidic Fluids at Resolution
Alteration Type
of Silicate
Minerals1
Sericitic
Assemblage
Intermediate
argillic
Relative
Abundance3
Confidence of
Interpretation4
quartz + sericite + pyrite ± chalcopyrite
sericite chalcopyrite
intermediate
low
5
quartz + sericite + pyrite ± chalcocite ± bornite
sericite chalcocite bornite
high
common
5
sericite - clay
high
very rare
3
topaz - zunyite sericite
high
very rare
2
quartz + pyrophyllite + kaolinite ± dickite + pyrite pyrophyllite - clay high
± topaz ± bornite ± chalcocite
very rare
4
topaz + alunite ± kaolinite ± dickite ± quartz +
pyrite ± chalcocite ± bornite
topaz - alunite clay7
high
rare
4
topaz + quartz ± zunyite ± bornite ± chalcocite
topaz - zunyite
—
rare
3
kaolinite ± dickite ± quartz ± pyrite ± bornite ±
chalcocite
clay
high
abundant
5
quartz + alunite ± kaolinite ± dickite ± pyrite ±
bornite ± chalcocite6
alunite - clay7
high
common
5
quartz + kaolinite ± dickite + pyrite + topaz ±
zunyite
clay - topaz zunyite
—
common
5
dickite
dickite
—
low
5
montmorillonite
montmorillonite
—
very
common
3
quartz + sericite + pyrite + kaolinite ± dickite ±
Transitional
chalcocite ± bornite
advanced
argillic-sericitic
quartz + topaz + pyrite ± sericite ± zunyite ±
bornite ± chalcocite5
Advanced
argillic
Abbreviation
Sulfidation
State of
Opaque
Minerals2
1
Based on criteria of Seedorff et al. (2005a)
Based on criteria of Einaudi et al. (2003); — = not determined by minerals present
3
Relative abundance: very rare, rare, low, common, very common, abundant
4
Confidence in interpretation that these minerals constitute an assemblage ranges from 1 = low confidence to 5 =
high confidence
2
5
Characterization of alteration type of this assemblage not definitive; could be transitional advanced argillic-sericitic or
sericitic
6
Probably also includes aluminum-phosphate-sulfate (APS) minerals (Harrison, 2007)
Though not observed in this study, the assemblage quartz - alunite also is almost certainly present at least locally at
Resolution (e.g., Fig. 18 a,b of Troutman, 2001); additional assemblages containing minerals such as andalusite and enargite,
also are likely to be documented in the future though it is unlikely that they will prove to be abundant
7