Precambrian
of anapparent
andreinterpretation
analysis
Structural
NewMexico
Mountains,
Manzano
central
unconformity,
angular
NM87131
Albuquerque,
of NewMexico,
University
Department
of Geology,
byScottE.Johnson,
4811, Australia]
Oueensland
Townsville,
James
CookUniversity,
oi Geology,
at Department
[Cuirently
Abstract
The contact between a Precambrian metaclastic unit and a massive Precambrian quartzite in the central Manzano Mountains has
previously been interpreted as an angular unconformity based on
ihe discordance of what was interpreted as bedding across the
contact. However, this work establishes that what was interpreted
as bedding is a transposition layering, and that the discordance
across the contact is a structural discontinuity rather than an angular unconformity. The rocks on either side of the contact have
undergone at least three periods of deformation and appear to have
the same deformation history, but different metamorphic histories.
Correlative structural fabrics on both sides of the contact are almost
perfectly realigned by a single rotation, which, combined with the
di-fferent metamorphic histories on either side of the contact, strongly
suggests a thrust fault with a rotational component of displacement
as the cause of the discontinuity. The discontinuity postdates the
youngest structural fabric correlated across the contact and predates the Pennsylvanian sediments that lie undisturbed across the
contact to the north.
Cenozoic
rocks
ffi
Poleozorc
r o ck s
34045'
Precombrion
rocks
O j i t os f o c k
Blue Springs
S c hi s t
M o s si v e
q u otrz i i e
W
L o w er
metoclostics
-.l-.....
F o u l t - b o l lo n d o w n f h r o w n
s i d e : d o t t e d w h e r eb u r i e d
2km
FIGURE L-Location and regional geology of a portion of the central Manzano Mountains (adaptedfrom Stark, 1956).The area studied in detail, and
shown in Figs. 3 and 4, is outlined in black.
Introduction
The Manzano Mountains form a fault-bounded uplift bordering
the easternedgeof the Rio Grande rift. The mountain rang-eextends
from Abo PasJto Escabosa,a distanceof approximately29 mi, and
consistsof multiply deformed Precambrianigneous and metamorphic rocks. The regional geology was summarizedby Reiche(1949)
and Stark (1956).
The study area for this report is locatedapproximately25-mi east
of Belen, oir the west side of the Manzano Mountains, and is contained within the NW1/+and SWt/a of the USGS Capilla Peak 71lz
of ComancheCanyon in the central Manzano Mountains (Fig. 1; see
Myers and McKay, 1972, fot the most recent geologic map of the
central Manzano Mountains). This contact has previously been interpreted as a Precambrianangular unconformity by Reiche.(1949),
Sta;k (1956),and Condie and Budding (1979)becauseof the discordanceof what was interpreted as bedding across the contact.
Basedon the correlation and analysis of structural fabric elements
and the comparisonof metamorphicconditions on both sidesof the
contact,as well as evidencefor faulting along the contact, the discordanceacrossthe contact is reinterpreted as a post-depositional
structural discontinuitY.
Alsoin thisissue
Geologicalobservationsat Carbon Coal Company's
No. 2 mine-a small but uniqueoperation
Palynologicalanalysesof several Pennsylvaniancoal beds,
Santa Fe County
Galleryof Geology
CibolaCounty border redefined
Clayton Lake
Cretaceousstratigraphyand biostratigraphy,
State Park
Service/News
New MexicoGeologicalSocietyabstracts
Staff notes
p.51
p. 54
p. 58
p. 59
p. 60
p .6 6
p. 67
p.72
soon
Coming
Late CenozoicPalomasFormationin south-centralNew Mexico-a
formal definition
The role of clay mineralsin the disposaland storageof hazardous
materials
Porphyry-typemineralizationand alteration,Organ miningdistrict
Paleontologyand correlationof a Lower Cretaceousoutlierin
RooseveltCounty
of the Cutler Formationred
Fluvialdepositionand paleoenvironment
beds, El Cobre Canyon
Lower meloclostics
B l u e S p r i n g sS c h r s t
TABLE 1-Definitions
used in this study.
Description
Element
so
Bedding in the massive quartzite. Younging directions defined
by crossbedding.
ce 1
Dominant cleavage in the study area. Transposition layering
in the lower metaclastics and Blue Springs Schist where it is
included together with Sj as So/Sr.
q
r2
Cleavage ranging from a closely spaced crenulation cleavage
to a well-developed schistosity. Overprints So/Srat an angle
generally greater than 10'. Axial-planar to numerous
mesoscopic folds. Shows a metamorphic differentiation in
schists defined by alternating, closely spaced layers of qtartzrich and mica-rich rock.
s3
Well spaced, nonpenetrative crenulation cleavage. Overprints
So/Srand S, at an angle generally greater than 60'.
so/sl
S2
=f,
Well spaced, nonpenetrative crenulation cleavage in Blue
Springs Schist. No correlative counterpart in the lower
metaclastics.
S3
M os si v e q u o r t z i t (eS d
Lro
Observed and calculated intersection lineation of So/S, and Sr.
L2
Stretching lineation observed on Sr surfaces. Defined by
preferred orientation and alignment of elongated chlorite and
muscovite. Interpreted as representing the direction of
maximum finite elongation during the second deformation
event (D).
FIGURE 2-Stereograms
showing the orientations of the
structural fabric elements describedin Table1 (lower hemrsphere,equal-areaprojections;
tic is true north). Contours are
in the sequence\7o, 37o, 67o
72%, 24%, and 48% per L%
area. The number of data
points is shown at the lower
ilgnt of each stereogram. Details of each stereogram are
summarized in Table 2. The
summary stereogram shows
the modal orientations of the
So/S1,Sr, and S, fabrics in the
lower metaclastics and Blue
Springs Schist. lm : Iower
m e t a c l a s t i c s ;B S S : B l u e
Springs Schist.
L2
Summory
@
s5(BSS)
""ry
August 1986 Nan Mexim Geology
and descriptions of the mesoscopicfabric elements
S.(lm)
New A4exnc@
GEOLOGY
o Science
andSeruice
Volume 8, No. 3, August 1986
Edifor Deborah A. Shaw
Dfifter: C:r die A. Salisbury
Published quarterly by
New Mexico Bureau of Mines and Mineral Resources
a division of New Mexi@ Institube of Mining & lbdmology
BOARD OF REGENTS
Ex Officio
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Alan Morgan, Suryintendentof Publiclnstruction
Appointed
SteveTorres, Pr6., 7967-7991,Socorro
Sec.ITreas.,1977-1987,
bs Cruces
Floyd,
Judy
Cilbert L. Cano, 1985-1991,Albuquerque
Lenton Malry, 7985-7989,Albuquerque
Donald W. Moris, 1983-1989,LosAlamos
New Mexico lnstitute of Mining & Technology
......
LaurenceH.Lattman
Prcsidnt..
New Mexico Bureau of Mines & Mheral Resources
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D i r n t o r. .
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DeputyDirector
Subscriptions:
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Editorielmotttr: Articles submitted for publication should
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of study. Address inquiries to Deborah A. Shaw, Editor
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Publishedas public domain, thereforereproduciblewithout ptrmission.Sourceuedit requesled.
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There is no evidencein the Blue Springs Schistof retrogrademetaLithologies, bedding, and stratigraphicfacing
metamorphic histories are juxThe lower metaclasticsare composedof interlayeredbrown to gray morphism. Thus, rocks with different
lower
metaclasticsand massive
the
between
at
the
contact
taposed
schist, gray phyllite, metavolcaniclasticrocks, ind minor meta-aikose, amphibolite, and white to gray quartzite. Lithologic layering quartzite.
defined by Fe-Ti oxide concentrations in the quartzite and metavolcaniclasticlayersis folded by rootless,intraformational,isoclinal
Structural fabric elements
folds with axial-plane foliations parallel to the compositional layering. Discontinuouspods and stringers of.the compositionallayers
Definitions and descriptions of the mesoscopicfabric elements
are common, as are isolated, isoclinal, fishhook-shapedfold noses used in this report are given in Table L. So/S',5., Sr, L20,and L' are
with axial planes parallel to the compositionallayerlng. Thus, the common in the lower mltaclasticsand Blue Springs Schist,but they
dominant layering in this unit is a transpositionlayering.
were not recognizedin the massivequartzite.Although a largepopThe massivequartziteis composedof white, gray,and occasionally ulation of fractures, some of which form conjugate sets, occurs in
blue or red, crossbeddedquartzite. Quartz grains that range from the massivequartzite,their relationshipto the So/S',S', and S. fabrics
0.1 to 1.0 mm in size form 99% of the rock with only traceamounts in this study is not clear; therefore, they were not included in this
of muscovite,Fe-Ti oxides, and tourmaline. In some areasdiscon- reoort.
tinuous layers,ranging from 1 to 10 cm thick, containconcentrations The transpositionlayering So/S'observedin the lower metaclastics
of euhedralmagnetite crystals up to 2 cm across.Primary bedding and Blue Springs Schist appearsto be a common phenomenon in
is well defined by Fe-Ti oxide concentrations and relatively thin (1- the Precambrianrocks of New Mexico (e.g', Bauer,1983;Callender,
10 cm) layers of pebbly and conglomeraticquartzite. Cros-sbedding 1983;McCarty, 1983;Armstrong and Holcombe, L982;Holcombe and
is defined by concentrationsof Fe-Ti oxides and, where interpret- Callender, 7982; Grambling, 1982; Grambling and Codding ' 1982;
able, shows consistentyounging to the southeast,toward the BIue Cavin et aL.,1982;Connolly, 1982).Evidencedocumenting that an
Springs Schist.No folds or transpositionfeatureswere recognized, early deformation event led to the development of a widespread
and the well-definedbedding featuresareinterpretedasrepresenting transposition layering in the central Manzano Mountains consists
original bedding orientation. In other words, the attitude and facing of: 1.)-rootless,
intraformational,isoclinalfolds with axial planesthat
of individual bedding featurestruly reflect the attitude and facing are parallel to the compositional layering and cut by the later S,
of the whole stratigraphicunit.
folialion; 2) discontinuouspods and stringers of the compositional
The Blue SpringsSchistis composedof green to brown schistand layering and isolated, isoclinal, fishhook-shapedfold noses with
greento gray phyllite with interlayeredwhite, gray,and green,rarely aiial planesparallelto the compositionallayering, both of which are
crossbeddedquartzite. The layering in the Blue Springs Schistcon- cut by the later S, foliation; 3) quartz-rich microlithons, seenin thin
tains the sametranspositionfeaturesseenin the lower metaclastics. section, that are parallel to the compositionallayering and cut by
Therefore,the dominant layering in the Blue Springs Schistis also the later S, foliation; and 4) mica alignment, seenin hand specimen
a transpositionlayering, and this transpositionlayering in the lower and thin section, that is parallel to the compositionallayering and
metaclasticsand Blue Spring Schistis fundamentally different from cut by the later S, foliation.
the primary depositionallayering observedin the massivequartzite.
Isolatedkink bands that overprint So/S'and S' occur locally in the
lower metaclasticsand Blue Springs Schist,but their rare occurrence
makes them relatively unimportant for the overall structure'
Metamorphism
The schistsand phyllites in the lower metaclasticscontain quartz,
muscovite,plagioclase,biotite, pseudomorphsof chlorite and muscoviteafter coarse(1 cm) staurolite,and rare garnet surrounded and
embayedby retrogradechlorite.
Electronmicroprobeanalysesof the embayed,relict garnetsreveal
what appearto be retrogradereactionrims. In the coreof the garnet,
up to within 10 microns of the rim, the garnet composition is conHowever, from
sistentwith the following average:AlorSpn,Pyr,oGrn.
within 10 microns of the rim up to the rim the compositionchanges
graduallywith Mn increasingand Fe and Mg decreasing,giving the
following average:Al.rSproPyrrGrr.
The plagioclasein the samerocks
is commonly sericitized,and optical properties reveal compositions
more calcicthan An,o.
The amphibolitesin the lower metaclasticscontainquartz, epidote,
plagioclase,calcite,and zoned amphiboles.The amphibolesare zoned
with blue-green hornblende cores surrounded by what are interpreted as retrograde rims of actinolite. The hornblende-actinolite
boundaries are commonly sharp, but irregular. The plagioclaseis
highly sericitized and its composition is unknown. The calcite is
consideredto be retrogradebecauseit occursexclusivelyas isolated
patchesand stringers within the blue-greenhornblende, and it is
totally absentin the surrounding rims of retrogradeactinolite. It is
not clear whether the epidote is prograde or retrograde;however,
much of it appears to be retrogradebecauseit occurs in close associationwith highly sericitized,nearly obliteratedplagioclase.
The pseudomorphsafter staurolite,garnetswith retrograderims,
calcicbut sericitizedplagioclase,and zoned amphibolesassociated
with retrograde calcite and epidote suggest that the lower metaclastics underwent lower amphibolite facies prograde metamorphism, followed by upper greenschistfaciesretrogrademetamorphism.
Mineral assemblagesin the Blue Springs Schistinclude chloritecalcite-biotite and chlorite-chloritoid-biotite, both with muscovite
and quartz, which suggestsupper greenschistfaciesmetamorphism.
Structural analysis
fabric elementsin Table 1 are shown
various
Stereogramsof the
in Fig. 2. Orientation data for the stereogramsof Fig. 2 are summarized in Table2.
The So/S,fabric in the lower metaclasticsis truncatedat the contact
with the massivequartzite (Fig. 3). It has been demonstratedthat
this fabric representsa transpositionlayering rather than bedding;
[?
of orientation data shown in Fig. 2. Planes are given
TABLE 2-summary
as dip and dip azimuth. Lines are given as plunge and plunge azimuth.
Fabric element
Lower metaclastics
so/s1
Orientation data
Number of data
modal So/S'
modal Sz
modal 53
modal L,
Lrogirdle
modal L2
90, 768
90,149
80, 46
vertical
90, 749
47, 59
r00
62, 126
70,705
66, 188
57
55
49
L2
modal So/S'
modal S,
modal 53
secondary
maximum S,'
modal Lro
L, girdle
modal L'
70, 00
54, 765
70, 705
65, 60
30
Massive quartzite
c,
modal 56
50, 130
54
c
s"
Lrn
L2
68
56
56
27
Blue Springs Schist
so/s1
s"
q
Lro
Nat: MexicoGeology August 1985
53
therefore, the truncation mav be a structural discontinuill,, due tcr
a l a t e r - s t a g de e f o r m a t i o n ,r a t h e r t h a n a n a n g u l a ru n c o n f ( ) r m i t vf.h c
discordance of the S. and Lr,,fabrics across the contact .tre shdwn in
Fig 4, and similar relationships for S. and L. can be sec.n in the
stereograms in Fig 2 In fact, the lack of alignment across the contact
of any of the structural fabrics of Fig. 2 strongly suggests post-S.
deformation.
The orientations of the fabric elements in the lower metaclastics
and BIue Springs Schist are compared in Tabie 3 before and after a
53' counter-clockwise rotation of the fabric elements in the lower
metaclasticsabout an axis plunging 45' to azimuth 94'. The nearperfect alignment of all five fabric elements in the lower metaclastics
- <r l1 - . 7
-T
with those in the Blue Springs Schist after rotation suggests that: 1)
they are correlative and formed during the same deformation event,
2) they were aligned at one time, and 3) rotational displacement has
occurred causing the present discordance of the various fabric elements in the two units.
The fact that the structural discontinuity is restricted exclusively
to the lower metaclastics-quartzitecontact stronglv suggests movement alonq the contact. Field evidence for movement along the contact is summarized in Fies. 3, 4, and 5 Within l-5 m of the contact
the S,,/S,fabric in the lo*er metaclasticshas rotated into alignment
with the contact. Fig. 5 shows sixteen S,,/S,and seven S. data points
that were collected in the narrow (1 5 m) zone near the contact.
-f
<-
<..<
(*-*x"/,,
,t7lf,Kx /l
,.Nll, ,.',tl/4:,
f*:X'',4/',
--'
Strheo
dooflronsposed
D e d d r n g O / S r)
--F
V e r l o l l r o n s o o s e db e d d r n o
(so/ )
......l-
S i r i k eo n d d r p o f b e d d r n q
Foull-bollon down'lhrown
s r d e ,d o t i e d w h e r e b u r r e d
S t r r k e o n d d r p o f c l e o v o g e( 5 2 )
r,ln6'ioq rc cordoc t: doshed
w h e r e o - p p r o xm o 1 d ;d o t t e d
wnereDuned
O
3OOm
F_!____J_______+
0
tooof .r
t r o ut - b o l l o ' nd o w n . h r o w rs d e , d o i l e d
where burred
O
30Om
FIGURE 3-Map of the area outlned in Fig. 1 showing the spatial variation
of the S./Si fabrrc in the lower metaclastics and Blue Springs Schist and thc
S u . f a b r i ci n t h e m a s s i v e q u a r t z r t e . D i p s a r e a l l s t e e p i n d v a r i a t i o n s i n d i p
values are summarized in the S,,/S,and S. stereograms in Fig. 2. The foimations are named and color coded in Fig. 1. Generalized rvest-eastcross
sectionsare shown in Fie b
48
August
1986
Nm Mexico Geologtl
-....
#
0
tpoofl
+
P l u n g e d i r e c ' l i o no f l r o n s p o s e d
b e d d i n g - c l e o v o g ei n ' l e r s e c l i o n
(Lzo)
8o-eo
+
+
60-80
+
40-60
+
?A-4o
f - i T t r o r o g f ,- r ' t o c t ; d o s h e d
w h e r e o p p r o x t m o l e :d o l t e d w h e r e
FIGURE 4-Map of the area outlined in Fig 1 showing the spatial variation
of the S, and Lrn fabrics in the lower metaclastics and Blue Springs Schist
Dips are all steep and the orientation data are summarized in the S, and Lrn
stereograms in Fig 2 The formations are named and color coded in Fig 1
Ceneralized west--€ast cross sections are shown in Fig. 6.
These data points have been plotted onto the contoured Sostereogram of the massive quattzite, and they show that the So/S,fabric
in the lower metaclasticsnear the contactis parallel to the contact.
As the contactis approached,the lower metaclasticsbecomehighly
silicified,but I have neverbeenableto get closeenoughto the contact
to find an actual movement zone. Thus, it is not clearwhether the
movement along the contact was brittle or ductile.
Discussion
Any structural explanation of the discontinuity along the lower
metaclastics-quartzitecontact must incorporate:1) the rotation required to realign the correlativefabricsin the lower metaclasticsand
Blue Springs Schist (Table3); 2) the faulting parallel to the contact
with a component of left-lateralmovement as implied by Figs. 3, 4,
and 5; and 3) the different metamorphic conditions on either side of
the contact.
Figs.6A-D representgeneralizedwest-eastcrosssectionsthrough
the study area (Fig. 3) that show a sequenceof hypothetical events
that meet the aboverequirementsand lead to the presentstructural,
metamorphic,and topographic relationships.Fig. 6,4 representspostS, time, just before faulting, during which upper greenschist facies
metamorphic conditions prevailed. In Fig. 68 a ductile thrust fault
with a 53'clockwise component of rotational displacementbrought
lower amphibolitefaciesrocks (lm,) in contactwith upper greenschist
faciesrocks (1m,,mq, and BSS).It was during and after this faulting
event that retrogrademetamorphismoccurredin lm.. Reversefaulting combinedwith left-lateraldisplacementthen occurredalong the
lower metaclastic-quartzitecontact truncating the rotational fault
and causing the So/S,fabric in lm. to rotate into alignment with the
TABLE 3-Comparison
of correlative fabric elements after a 53' counterclockwise rotation of the fabric elements in the lower metaclastics about an
axis plunging 45" to azimuth 94'. Planes are given as dip and dip azimuth.
Lines are given as plunge and plunge azimuth.
Fabric
elemenl
modal SolSt
modal St
modal S,
modal L,
modal Lt
Lower metaclastics
(Before
(After
rotation)
rotation)
90, 168
90, 749
80, 46
vertical
47, 59
67,723
70, 104
66, 788
54,165
oJ,
oz
Blue Springs Schist
modal
modal
modal
modal
modal
So/S1
52
53
L2p
Lz
contact (Fig. 6C). Later erosion then led to the present structural,
metamorphic,and topographicrelationships(Fig. 6D).
This model relieson two hidden structural-metamorphicfeatures:
the rotational thrust fault and the existence of upPer greenschist
faciesmetamorphic mineral assemblagesin lm'. The model is only
intended to representone possiblekinematic solution to the problem.
The timing of the structural discontinuity can be constrainedin
three ways. First, the discontinuity Postdatesthe S. fabric because
that fabric is realigned after rotation (Table3). Second,the discontinuity predates the Pennsylvaniansedimentsthat lie undisturbed
acrossthe contact to the north (Fig. 1). This second constraint reouires that the discordant relationshipsacrossthe lower metaclastics-quartzite contact observed in thi study area continue to the
mapping to the north suggeststhat the strucnorth. Reconnaissance
tural and metamorphicrelationshipsare the same;therefore,I considerthis constraintvalid. Third, the discontinuity probablypredates
the S.'fabric in the Blue Springs Schist (Fig. 2 and Table2) as follows.
The S.'crenulation cleavagein the Blue Springs Schist has no correlative counterpart in the lower metaclastics.If Sr' predates the
discontinuity, then it should also appear in the lower metaclastics.
However, if S.'postdatesthe discontinuity, it is possiblethat rather
than crenulating the lower metaclasticsit would reactivateand tighten
the So/S,fabric becausethe angle between the two fabricsis so small
(Table2). As seenin Table2, Sr'in the Blue Springs Schistintersects
So/S,in the lower metaclasticsat an angleof lessthan 15",supporting
the interpretation that S.'postdates faulting. Bell (1986)discussed
the mechanismsand processesof the reactivation of earlier foliations. Alternatively, S. and S,'may simply be conjugatecrenulation
cleavageswith S.'not developedin the lower metaclastics.
Previouslv,the contact between the lower metaclasticsand massive quartzile has been interpreted as the contactbetween two separatestructuralterraneswith differentdeformationhistories(Reiche,
1949;Stark, 1956;Condie and Budding, 7979).These workers recognized two periods of de{ormationto the north of the contactand
only one to the south. However, I recognizedat least three periods
of deformation that are completelv correlatableacrossthe contact.
Grambling (1982)has also recognized at least three periods of deformation in the Blue SpringsSchist,and Bauer(1983)has recognized
62,726
70, 105
66, 1,88
54, 165
65, 60
E
BSS
\
4.
\
\--tq
lmr
/,,,
mq
lmz
lmr
B
A
lmz
FIGURES-Stereogram showing 16 So/S,(X), and seven S, (O) data
points from the lower metaclastics that were collected near the
contact with the massive quartzite. Thev are overprinted onto the
contoured Sostereogramfor the massivequartzite;'tic is true north.
N'
FIGURE6-Generalized west--eastcrosssections through the study area (see
Fig. 3 or 4 for location) showing a hypothetical sequenceof eventsleading
to the currently observed structural, metamorphic, and topographic relationships. The sequenceis explainedin the discussionsection.lm, : 1o-"t
metaclasticswith upper greenschistfaciespeak metamorphism; lm, : lower
metaclasticswith lower amphibolite faciespeak metamorphism; BSS : Blue
Springs Schist with upper greenschist facies peak metamorphism; mq :
massive quartzite with upper greenschistfacies peak metamorphism.
Nm Mexico Geology August 7985
at least three periods of deformation in the southern Manzano Mountains.
Conclusions
Field observations and structural and metamorphic analyses suggest that the discordance observed across the contact between the
lower metaclastics and the massive quartzite in the central Manzano
Mountains is a structural discontinuity rather than an angular unconformity. This conclusion is based on five observations:"1)microscopic and mesoscopic similarities between the fabric elements
correlated across the contact, 2) identical crosscutting geometric relationships displayed by the fabric elements on each side of the
contact, 3) evidence for movement along the contact, 4) different
metamorphic histories across the contact, and 5) the fact that the
contact.
Timing of the discontinuity is uncertain, but it probably postdates
the third deformation fabric (S.) and predates the Pennsylvanian
sediments that lie undisturbed across the discontinuity to the north.
ACKNOWLEDGMENTS-I
thank P. W. Bauer, T. H. Bell, f . F. Callender,
J. A. Grambling, and M. L. Williams for their enthusiastic support
and animated discussions concerning the Precambrian rocks in the
central Manzano Mountains. J. F. Callender, J. A. Grambling, K. E.
Karlstrum, M. f . Kisucky, G. Oertel, l. M. Robertson, a.,d'M. L.
Williams reviewed various drafts of this manuscript; all comments
were greatly appreciated. I thank R. V. Metcalf for iunning the electron microprobe. Field work was supported in part by the Department of Geology, University of New Mexico, Albuquerque.
References
Armstrong, D G., and Holcombe, R J , 7982, Precambrian rocks of a portion of the
Pedemal Highlands, Tonance County, New Mexico: New Mexico GeologicalSociety,
Guidebook to 33rd Field Conference,pp 203)1.0
Bauer, P W ,1.983,Geology of the Precambrianrocks of the southern Manzano Mountains, New Mexico: Unpublished M S thesis, University of New Mexico, Albuquerque, 133 pp
Bell, T H , 1985, Foliation development and reactivation .in metamorPhic rocks-the
reactivation of earlier foliations and decrenulation due to shifting Pattems of deformation partitioning: Journal of Metamorphic Geology, v. 4, no 4
Callender, I F , 1983, Transposition structures in Precambrian rocks of New Mexico:
New Mexico Geological Society, Guidebook to 33rd Field Conference, pp 743-745.
Cavin, W J, Connolly,J R., Woodward, L A., Edwards, D L, and Parchman,M,
1982, Precambrian stratigraphy of the Manzanita and north Manzano Mountains,
New Metco: New Mexico Geological Society,Guidebook to 33rd Field Conference,
pp.791.-1.95.
Condie, K. C., and Budding, A I , 1979, Geology and geochenistry of Precambrian
rocks, central and south-central New Mexico: New Mexico Bureau of Mines and
Mineral Resources,Memoir 35, 50 pp
Connolly, J R , 1982, Structure and metamorphism in the Precambrian Cibola gneiss
and Tijeras greenstone, Bernalillo County, New Mexico: New Mexico Geological Society, Guidebook to 33rd Field Conference, pp 197)02
Grambling, J A ,1982, Precambrianstructuresin Canon del Trigo, Manzano Mountains,
cenhal New Mexico: New Mexico Geological Society,Guidebook to 33rd Field Conference, pp 277-220
Grambling, J A, and Codding, D B ,1,982, Stratigraphic and structural relationships
of multiply deforrned Precambrian metamorphic rocks in the Rio Mora area, New
Mexico: Geological Society of America, Bulletin 93, pp 1.27-'137.
Holcombe,R J , and Callender,J F , 7982,Structuralanalysisand stratigraPhicProblems
of Precambrianrocks in the Picuris Range,New Mexico:GeologicalSocietyof America,
Bulletin 93, pp 1.38-'1.49.
McCarty, R M, 1983, Structural geology and pehology of part of the Precambrian
Vadito Group, Picuris Mountains, New Mexico: Unpublished M.S thesis, University
of New Mexico, Albuquerque, 158 pp
Myers, D A , and McKay, E J , 1972,Geologic maP of the Capilla Peak quadrangle,
Torranceand ValenciaCounties, New Mexico: U S GeologicalSuruey,GeologicQuadrangleMap GQ-1008,scale1:24,000
Reiche,P, 1,949,GeologyoI the Manzanita and north Manzano Mountains, New Metco:
GeologicalSocietyofAmerica, Bulletin 60, pp 1783-121.2
Stark, J T, 1955,Geology of the south Manzano Mountains, New Mexico: New Meico
Bureau of Mines and Mineral Resources,Bulletin 34, 49 pp
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