Supplemental Electronic Materials
Mentzer, S.M. et al. “Micromorphological contributions to the study of ritual behavior at the
Ash Altar to Zeus on Mt. Lykaion, Greece”
Contents:
1
Correlation between the stratigraphy described here and the baskets and SU’s
in Romano and Voyatzis (in press, 2014) and Starkovich et al. (2013)
2
Descriptions of microscopic features of samples collected from Trench Z,
Trench ZZ and reference soils
2.1
Geogenic components
2.2
Anthropogenic components
2.3
Biogenic components
2.4
Microstructures and sedimentary fabrics
2.5
Descriptions of other post-depositional features
3
Supplemental references
1. Correlation between the stratigraphy described here and the baskets and SU’s in Romano
and Voyatzis (forthcoming, 2014) and Starkovich et al. (2013)
The geoarchaeological stratigraphic units described here are based on sedimentary
characteristics observed in the field. These units correspond roughly to the broad field-based
units (SU’s) in Romano and Voyatzis (in press, 2014), however the nomenclature differs. First, a
simplified version of the stratigraphic sequence was presented in the text and figures in order
to adhere to standard archaeological conventions by which stratigraphic units are numbered
either in order from the bedrock upward, or from the surface downward. Second, the sampling
column described in Starkovich et al. (2013: Fig.1) correlates to the type section, however only
basket and spit numbers were listed.
Stratigraphic
units
(this study)
Z-I
Z-II
Z-III
Sampled excavation
baskets
Z92, Z126, Z134,
Z138, Z140, Z14
Z36, Z57, Z139
Z36, Z132, Z133
Stratigraphic units (SU)
(Romano and Voyatzis, forthcoming, 2014) or
Starkovich et al. (2013) sampling spits (A#)
SU7, SU18
SU7, SU16, A9
A8, SU16
Z-IV
Z-V
Z-VI
Z15, Z22, Z23, Z24,
Z44, Z53, Z133
Z10, Z14, Z34, Z37/42
Z4, Z8
SU11
SU2
SU1, SU13
2. Descriptions of microscopic features of samples collected from Trench Z, Trench ZZ and
reference soils
2.1 Geogenic components
Limestone fragments are the most abundant geogenic component of the altar stratigraphic
sequence and are common within the cobble- and gravel-sized particle fraction. In thin section,
the limestone fragments are generally composed of microcrystalline calcite (micrite), with rare
fragments containing visible microfossils. Many fragments also exhibit veins or internal zones
consisting of larger, sparitic (>4 μm) calcite crystals (see text Fig. 4a). These veins range in
diameter from less than one millimeter to multiple centimeters. Individual calcite crystals or
multi-crystalline rock fragments are rare to common components of the sand-sized fraction of
the altar sediments. These materials are derived from the limestone bedrock, and exhibit
variable degrees of chemical weathering as evidenced by angular to well-rounded fragment
edges. The larger, gravel-sized fragments of limestone that are visible in thin section are also
angular to rounded. Although rounded limestone cobbles are present in the local soil profiles,
gravel- and sand-sized fragments of limestone are absent in both loose samples and thin
sections. Likewise, sand-sized fragments of limestone are absent from the basal units (Units Z-I
and Z-II) within Trench Z and Units ZZ-I, ZZ-II and ZZ-IV in Trench ZZ.
Quartz, chert, and clay comprise the siliceous component of the geogenic sediment at the site
(see text Fig. 4b). Silt-sized fragments of quartz are present in all analyzed samples, while chert
fragments are present in many samples within the gravel- and sand-sized particle fraction. Both
quartz and chert are present within the local bedrock, the former comprising rare inclusions
within the limestone, and the later present as thin beds that have been highly fractured due to
tectonic activity. Quartz is also present within other types of bedrock in Mt. Lykaion, including
within the sandstone member of the Pindos Group. Like the limestone fragments described
above, chert, and quartz are natural components of the altar sediments, as well as the local
soils, and are derived from the weathering of the bedrock. Both chert fragments and quartz are
most abundant in the local soils, and in the basal sediments within the Trench Z sequence. The
chert that is present within the bedrock is impure, and contains thin veins and zones of calcite.
Gravel- and sand-sized fragments of sandstone and siltstone are exceptionally rare, but are
present in one sampled local soil and some samples from Trenches Z.
Red clay comprises the matrix of the lowest stratigraphic unit in the altar (Unit Z-I in Trench Z
and Unit Z-I in Trench ZZ), as well as the local soils. In some samples, red clay fills cracks within
cracks within fragments of limestone.
2.2 Anthropogenic components
Wood ashes are abundant in the Trench Z sediments (see text Fig. 5a). Wood ashes are typically
composed of silt-sized aggregates of micritic calcite (CaCO3) that form as a result of the
breakdown and recrystallization of calcium oxalates in plant tissues during combustion
(Brochier and Thinon 2002, Canti 2003, Shahack-Gross and Ayalon 2012). Some ashes also
contain a siliceous component sourced from the plant phytoliths (Canti 2003, Scheigl et al.
1994). This component is largely absent in the Mt. Lykaion deposits, although unburned
phytoliths are present in some samples (see below). The calcareous components of wood ashes
are identified in thin section by their characteristic rhombic aggregate morphologies, grey color
in PPL, and high-order interference colors in XPL. Wood ashes are the most abundant
component of the silt-sized particle fraction in Trench Z within Stratigraphic Unit Z-IV. Sandsized aggregates of cemented ashes are also present throughout the upper units of the
sequence (Z-III through Z-VI), but are rare compared to loose ashes. Ashes are not present in
the sampled soils.
Fragments of charcoal (see text Fig. 5b) comprise another sedimentary component that sources
from the burning of wood and other plant tissues. Fragments of charcoal are both black and
opaque in thin section. Large fragments often contain vesicles and visible plant tissues, such as
annual growth rings. Unlike humified organic materials, which can also appear black and
opaque, charcoal fragments exhibit high reflectivity under RL. Sub-rounded to rounded
fragments of charcoal are present in the sand- and silt-sized particle fraction of the sediments
sampled from Trenches Z and ZZ. Charcoal fragments are very rare component of the soils
formed on colluvium at the base of the mountain summit, and are absent from the soil sampled
from the roadcut.
Fragments of burned bone are another abundant component of the Mt. Lykaion Trench Z
sediments, comprising the majority of the gravel- and sand-sized particle fraction in the
samples collected from Units Z-III through Z-VI. Bone fragments are also present in Trench ZZ
Units ZZ-I, ZZ-II, and ZZ-IV, and in lower quantities in Trench Z Unit Z-II. Bone fragments are
identified in thin section by their pale brown to black color in PPL, and low order grey
interference colors in XPL. Osseous tissue structures are also visible, including pores within
cancellous bone fragments, and haversian canals in cortical bone fragments. Both cancellous
and cortical bone fragments are composed of aligned fibers of hydroxlyapatite, which
comprises the mineral component of bone. This mineral is typically visible in XPL, yielding along
with collagen, a characteristic “ropy fabric” (Karkanas and Goldberg 2010).
The majority of the bone fragments observed in thin section in the Lykaion sediments are
burned to the point of charring or calcination. Burned bone fragments exhibit several features
visible in thin section that allow them to be distinguished from non-burned bones (Courty et al.
1989, Schiegl et al. 1996, Shahack-Gross et al. 1997, Hiller et al. 2003, Hansen and Cain 2007,
Angelucci 2008, Karkanas and Goldberg 2010). In the Lykaion samples, most burned bone
fragments are consistent in color and morphology with experimental samples that underwent
“medium-high” to “extremely high” heating (Hanson and Cain 2007). Charred bone fragments
(“medium-high”) are dark brown to black in PPL, while calcined bone fragments (“high” to
“extremely high”) are typically pale yellow to white in color in PPL (see text Fig. 5c). Calcined
bone fragments also exhibit dull grey to white interference colors in XPL (see text Fig. 5d), and
white color under darkfield illumination. The absence of the characteristic “ropy fabric” typical
of fresh bone in XPL, and the white color under darkfield illumination are due to loss of collagen
during heating. Cracking is also observed in some samples.
Zooarchaeological studies of the gravel-sized bone fragments reveal that 99% of the
assemblage from Units Z-IV are calcined (Starkovich in Romano and Voyatzis forthcoming,
2014). This level of burning intensity allowed Starkovich et al. (2013) to directly date the calcite
fraction of the burned bone tissues using a radiocarbon dating method developed and refined
by De Mulder et al. (2007), Lanting et al. (2001), Olsen et al. (2008) and Van Strydonck et al.
(2009). ATR-FTIR analyses of bone fragments indicate that burning temperatures reached more
than 700°C (Starkovich et al. 2013, Fig. 2). Starkovich et al. (2013) also report the presence of
infrared peaks at 2012 cm-1, which may be indicative of burning in the presence of flesh (Hüls
et al. 2010, Van Strydonck et al. 2010).
Char is a vesicular substance that is black in both PPL and XPL. Two forms of the material, “bone
char” and “fat-derived char” are described by Clark and Ligouis (2010), Goldberg et al. (2009)
and Miller et al. (2009). The char in the Mt. Lykaion sediments is of the latter type and is
identified in thin section by its black color and high reflectivity under RL, and the presence of
internal vesicles and fissures. Unlike the vesicles in charcoal, the vesicles in fat-derived char are
distributed randomly. In the Lykaion sediments, fragments of char are present in the sand-sized
particle fraction (see text Figs. 5e, 5f). Some burned bone fragments also exhibit char adhering
to their edges.
Fragments of ceramic vessels are rare components of the Trench Z sediments that are visible in
thin section, although many sherds, as well as intact miniature vessels were recovered during
excavation. When present in the studied samples, ceramic fragments are gravel-sized; contain
tempering materials, including limestone, chert and shale; and exhibit a variety of internal
fabrics. Additional petrographic analyses of a representative sample of the ceramics collected
during excavation will be conducted in the future by E. Kiriatzi, and are not the topic of the
present study.
2.3 Biogenic components
Biogenic components of the sampled sediments include roots, fragments of fresh organic
material, humified organic material, snail shells, and phytoliths. Each of these materials, with
the exception of the shell fragments, derives from different types of plant tissues. Within
Trench Z, organic material and phytoliths are most abundant at the top of the stratigraphic
sequence, particularly within samples collected from the uppermost five cm of Unit Z-VI. These
materials are present as loose components of the sand-sized particle fraction, as well as within
rounded aggregates that are consistent in morphology with the fecal pellets of rodents. Organic
materials, roots, and phytoliths are also present in the O horizons of local soil profiles.
2.4 Microstructures and sedimentary fabrics
The fine and coarse sedimentary components in both the local soils and the altar sediments are
arranged into a limited number of related distributions, microstructures and fabrics that are
reflective of both depositional and post-depositional processes acting on the deposits. The local
soils are significantly finer in texture relative to the sediments from Trench Z and ZZ. Red clay
and quartz silt are the most abundant components of these samples, resulting in an overall
porphyric related distribution of the fine materials with respect to the coarse materials.
Localized domains of microaggregated fine materials are also present as infillings within
chamber voids (Fig. 6a). These infillings are termed passage features or biogalleries, and form
as a result of post-depositional insect activity (Kooistra 1978, Kooistra and Pulleman 2010). The
local soils contain both crack and channel voids, and exhibit granular grading to sub-angular
blocky structures (the latter more dominant at depth). Channel voids in these sediments result
from the activities of plant roots, as evidenced by the presence of fresh or partiallydecomposed root fragments within several of the channel voids.
In Trenches Z and ZZ, localized granular grading to sub-angular blocky structures are also
present within the lowest stratigraphic units, however the dominant microstructure in the altar
sequence is a granular grading to channel structure. With the exception of Unit Z-I at the base
of the sequence, which generally exhibit a porphyric related distribution (see Fig. 4b), fine and
coarse materials are aggregated in an enaulic related distribution with the space between
aggregates occupied by compound packing voids of variable size (see Fig. 6b). Other void types
are channels and chambers. Biogalleries are present throughout the sequences in Trench Z and
ZZ (Fig. 6b). In sediments containing abundant anthropogenic materials, the sedimentary
aggregates, interpreted as insect fecal pellets (Brewer 1964), within the galleries contain
fragments of bone, charcoal, and sometimes ash (Fig. 6c). Unit IV, Feature Z3, contains fewer
biogalleries and less void space than other units but still exhibits an enaulic related distribution.
Fecal pellets containing organic material are present only in one sample collected from the
ground surface. These pellets are compositionally distinct from the insect fecal pellets, and are
consistent in morphology and internal fabric with the excrement of a small herbivore, such as a
rodent.
2.5 Other post-depositional features
A variety of post-depositional microscopic features, or pedofeatures are present in the Mt.
Lykaion Trench Z and ZZ sediments, as well as in the local soil profiles. These features include
clay coatings of voids, dissolution features, and secondary mineral precipitates. The main
pedofeature types are illustrated in Figure 7.
Limpid clay coatings are present on the edges of crack voids in samples collected at depth from
the local soils (Fig. 7a). Clay coatings of voids are exceptionally rare in the samples collected
from the mountain summit; they are only present in Units ZZ-I and ZZ-II. Reworked limpid clay
coatings, or papules (Fig 7b), are present in both the local soil sampled from Trench KK and
within the Trench Z basal Units Z-I and Z-II, and Trench ZZ Unit ZZ-I.
Dissolution features (Figs. 7b, 7c, 7d) are present within the Trench Z sediments and are most
abundant in the basal units and uppermost 30-40 cm of the stratigraphic section. These
features include denticulate, serrated or mamillate edges of micritic portions of limestone
fragments, and digitate sparry calcite veins on limestone fragments. The former features are
typical carbonate weathering patterns (e.g., Delvigne 1998) and result from dissolution of
fragment edges in the presence of acidic groundwater. The digitate veins form when
differential dissolution of rock fragment edges first removes the micritic calcite matrix, leaving
behind the more resistant spar. Dissolution features are also present within chert fragments.
These include exterior zones that do not contain calcite veins or impurities. Instead, veins
contain red clay infillings or empty space, and calcite-crystal-shaped voids (mouldic voids, sensu
Durand et al. 2010) are also present. These weathering “rinds” are present on chert fragments
from Units Z-II and Z-III. In samples from the local soils, calcite is not present within the interiors
of chert fragments, however mouldic voids are present within the fragments.
Secondary minerals are present in the local soils and within the Trench Z and Trench ZZ
sediments. Concentric nodules composed of iron and manganese oxides (Fig. 7e) are abundant
within the local soils. Iron oxides, in Red Mediterranean soils, are thought to form as a result of
seasonal wetting and drying and are preserved under warm climatic conditions (Yaalon 1997,
Yassoglou et al. 1997). These features are also present in Trench ZZ, Unit ZZ-I. Secondary calcite
is present within the Trench Z sediments in the form of microlaminated micritic calcite and
needle calcite crystals adhering to the undersides of gravel-sized fragments of limestone and
bone (Fig. 7f). These features, called pendants, are also visible on fragments of limestone, bone,
and ceramic vessels recovered during excavation. Pendants form at depth within soils as a
result of evaporation of groundwater that contains dissolved calcium carbonate (Durand et al.
2010).
3. Supplemental references
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