AKLIS SITE
Sherd Petrographic
Descriptions
Plane polarized light is
just visible light under the microscope. Crossed (X) polarized
light allows you to see mineral characteristics such as twinning
in the feldspar and alteration. At 2.5X magnification, the
distance across the slide is 4.8 mm and at 10 X magnification it
is about 1.2 mm.
Level 2 - Aklis 134.13: This sherd has recognizable
features consistent with an oxidized firing. There is no distinct
gray-black reduction core and the outer edge of the sherd looks
baked (about 0.8 mm deep). The temper is a mixture of quartz and
feldspar mineral grains with angular to subangular rock fragments
composed of either limestone/carbonate (limestone intraclasts or
bioclasts) or polymineralic igneous rock (feldspar +/-
plagioclase with very little quartz). A few mollusc shell
fragments (~0.8 x 0.2 mm) are found.Level 3 - Aklis 135.17: This
sherd has an overall dark black to black-red colour and may
indicate reduction firing (no visible oxidation or baking as in
sample 143.13). Temper is a mixture of angular igneous rock
fragments (1 x 1.5 mm) composed of plagioclase (heavily altered
to sericite) + feldspar + little quartz along with some feldspar
(both plagioclase and K-feldspar) mineral grains and a few clasts
that are either shale rock fragments or argillaceous clay clots.
134.13 (2.5X plane polarized light) Shell
fragment (upper left corner), carbonate intraclasts (light tan
subrounded clast in centre) and some small rock fragments –
this sample is probably the best manufactured of the sherds from
Aklis I have seen.
Level 3 - Aklis 135.17: This sherd has an overall dark
black to black-red colour and may indicate reduction firing (no
visible oxidation or baking as in sample 143.13). Temper is a
mixture of angular igneous rock fragments (1 x 1.5 mm) composed
of plagioclase (heavily altered to sericite) + feldspar + little
quartz along with some feldspar (both plagioclase and K-feldspar)
mineral grains and a few clasts that are either shale rock
fragments or argillaceous clay clots.
135.17 (2.5 X plane polarized light) Note the
black colour of the paste. This one was reduced when fired. Rock
fragment temper.
135.17 (2.5 X cross polarized light) Same view
as plane polarized. Shows the rock fragment temper in more
detail.
Level 4 - Aklis 135.13:
This sherd has a hodgepodge of temper types. Mineral grains are
quartz (both monocrystalline and polycrystalline) and feldspar
(both heavily altered plagioclase and blocky Carlsbad twinned
k-spar). Rock fragments are mostly limestone/carbonate clasts and
some heavily oxidized (by firing?) clay clots (or in one case - a
possible shale clast - about 2 x 1.2 mm). This sample has a few
of those mafic mineral grains.
135.13 (2.5X plane polarized light) Shale and
rock fragment temper.
135.13 (2.5X cross polarized light) Same view as
plane polarized. Shows the rock fragment (centre) which is
altered plagioclase + mafic mineral (opaque minerals). Also show
the shale fragments (lower right). The large clast (upper left)
is a rock fragment that I would tend to define as a turbidite
because of the fine grained matrix and coarse grained angular to
subangular rock and shell fragments.
135.13 (2.5 X plane polarized light) Shale
fragment (dark red), carbonate intraclasts (rounded to subrounded
grains, right of centre) and rock fragments.
Level 5 - Aklis 137.29:
This sherd has an overall dark black to black-red
colour and may indicate reduction firing. Temper is mainly
igneous rock fragments (2 x 1.5 mm) composed of plagioclase and
K-spar. There are also some feldspar mineral grains and a few
mafic mineral grains whose optical properties suggest amphibole
(or clinopyroxene).
137.29 (2.5 X plane polarized light) Rock
fragments as temper.
137.29 (2.5 X cross polarized light) Same view
as plane polarized. Shows plagioclase rock fragment temper (near
centre; note that this shows little alteration) and different
rock temper near top (plagioclase + k-spar; note the difference
in alteration).
Level 6 - Aklis 138.29:
This sherd is shell (mollusk - includes a few forams and some
echinoderm fragments) tempered. The remainder of the temper
material includes a few carbonate intraclasts and bioclasts, some
subangular to subrounded monocrystalline quartz grains, a couple
of plagioclase - K-spar rock fragments and one grain that is a
volcanic glass (ash) fragment.
138.29 (2.5 X plane polarized light) Carbonate
intraclasts and rock fragments (composed of plagioclase +
quartz).
138.29 (2.5 X cross polarized light) Same view
as plane polarized. Carbonate intraclast to centre right, rock
fragments (upper right corner and left corner - the bright
highlights on these fragments is the sericite alteration of the
plagioclase).
138.29 (10 X plane polarized light) Mollusc
shell fragment (left of centre) and monocrystalline quartz
mineral grain (top right of centre). A few small carbonate
intraclasts.
Level 7 Aklis 139.22: This sample is a coarse shale
(angular to subangular shape) tempered sherd. There are some
quartz (monocrystalline and polycrystalline) and feldspar
(probably K-spar, Carlsbad twinned) mineral grains in the temper,
but it is dominated by shale rock fragments (which mostly have
tiny feldspar mineral grains within them). No evidence of coil
breaks was found.
139.22 (2.5 X plane polarized light) Shale, rock
fragment and mineral grain as temper.
139.22 (2.5 X cross polarized light) Same view
as plane polarized. Shows the difference between the red rounded
shale fragments and the lower relief but highly altered rock
fragments. The small (0.2 – 0.4 mm) blocky mineral grains
are feldspar (either plagioclase or k-spar).
Level 8 - Aklis 140.15: This sherd is both shale and
rock fragment tempered. It has a dark brownish-black colour to
the paste and is dominated by coarse (2 x 1.2 mm) subangular to
subrounded shale rock fragments (which show a separation void
around their margins - probably a contraction effect after/during
firing). The igneous rock fragments are smaller than the shale
fragments (0.4 x 0.2 mm) and are mostly feldspar (probably
plagioclase due to sericite alteration) + mafic minerals (either
hornblende or one of the calcic amphiboles). There are some
quartz mineral grains and some of the blocky to subrounded K-spar
grains in the temper.
140.15 (2.5 X plane polarized light) Subrounded
to blocky shale fragments with separation void rimming the
fragments. This sherd is tempered with this material.
Level 9 - Aklis 141.2: This sherd is dominated by
coarse, angular to blocky plagioclase + K-spar igneous rock
fragments. The plagioclase is altered to sericite mica. The
overall colour of the paste is a black-gray and suggests reducing
conditions during firing. The temper distribution appears to be
seriate because the rock fragments appear to have a range of
sizes (2 x 1.2; 1.8 x 1.2; 0.8 x 0.8 mm).
141.2 (2.5 X plane polarized light) Plagioclase
+ k-spar rock fragments (this sherd is tempered with only this
stuff).
141.2 (2.5 X cross-polarized light) Same view as
plane polarized, but show the twinning of the plagioclase.
Level 10 Aklis 142.15b: This sample is a
foram-tempered sherd. There are a few shell fragments (either
mollusc or gastropods shell), but the most abundant and visible
fossil is the foram in a variety of forms and arrangements.
Examination indicates that these are either Neogene or Paleogene
in age. The forams are planktonic and include Orbulina (single,
large spherical foram) which is Neogene in age. In addition to
the forams, the temper is a mixture of rock fragments (igneous,
shale and carbonate), plagioclase and K-spar mineral grains and a
few (< 1%) polygranular quartz grains (with sutured grain
boundaries suggesting probably devitrified volcanic glass).
Overall color suggests oxidizing conditions and no evidence for
coil breaks was found.
142.15b (2.5 X plane polarized light) Planktonic
foraminifera (single round sphere to the upper left of centre is Orbulina).
A multi-chambered foram is shown in centre. Angular rock
fragments of plagioclase +/-
k-spar (upper right corner).
142.15b (10 X cross polarized light) Planktonic
foram (right) and plagioclase mineral grains (stripes are the
twinning). Both polysynthetic and Carlsbad twin laws shown in
these fragments.
Level 11 Aklis 143.2:
This sherd is tempered with angular (to subangular) plagioclase +
K-spar and plagioclase + amphibole igneous rock fragments,
subrounded to blocky shale fragments and some plagioclase and
K-spar mineral grains. Overall color suggest oxidizing
conditions.
143.2 (2.5 X plane polarized light) Rock and
shale fragments as temper (subangular to subrounded in grain
shape).
143.2 (10 X plane polarized light) Closer view
of plagioclase + k-spar rock fragment (top), feldspar + amphibole
rock fragment (righ; the amphiboles are slightly pleochroic in a
green-brown colour range), k-spar mineral grain (left – with
the funny squiqqles and light yellow colour - this is a quartz
exsolution feature ). A small rounded shale fragment is directly
about this mineral grain.
134.13 (2.5X plane polarized light) Shell
fragment (upper left corner), carbonate intraclasts (light tan
subrounded clast in centre) and some small rock fragments –
this sample is probably the best manufactured of the sherds from
Aklis I have seen. 
135.17 (2.5 X plane polarized light) Note the
black colour of the paste. This one was reduced when fired. Rock
fragment temper. 
135.17 (2.5 X cross polarized light) Same view
as plane polarized. Shows the rock fragment temper in more
detail. 
135.13 (2.5X plane polarized light) Shale and
rock fragment temper. 
135.13 (2.5X cross polarized light) Same view as
plane polarized. Shows the rock fragment (centre) which is
altered plagioclase + mafic mineral (opaque minerals). Also show
the shale fragments (lower right). The large clast (upper left)
is a rock fragment that I would tend to define as a turbidite
because of the fine grained matrix and coarse grained angular to
subangular rock and shell fragments.
135.13 (2.5 X plane polarized light) Shale
fragment (dark red), carbonate intraclasts (rounded to subrounded
grains, right of centre) and rock fragments. 
137.29 (2.5 X plane polarized light) Rock
fragments as temper. 
137.29 (2.5 X cross polarized light) Same view
as plane polarized. Shows plagioclase rock fragment temper (near
centre; note that this shows little alteration) and different
rock temper near top (plagioclase + k-spar; note the difference
in alteration). 
138.29 (2.5 X plane polarized light) Carbonate
intraclasts and rock fragments (composed of plagioclase +
quartz). 
138.29 (2.5 X cross polarized light) Same view
as plane polarized. Carbonate intraclast to centre right, rock
fragments (upper right corner and left corner - the bright
highlights on these fragments is the sericite alteration of the
plagioclase). 
138.29 (10 X plane polarized light) Mollusc
shell fragment (left of centre) and monocrystalline quartz
mineral grain (top right of centre). A few small carbonate
intraclasts. 
139.22 (2.5 X plane polarized light) Shale, rock
fragment and mineral grain as temper.
139.22 (2.5 X cross polarized light) Same view
as plane polarized. Shows the difference between the red rounded
shale fragments and the lower relief but highly altered rock
fragments. The small (0.2 – 0.4 mm) blocky mineral grains
are feldspar (either plagioclase or k-spar). 
140.15 (2.5 X plane polarized light) Subrounded
to blocky shale fragments with separation void rimming the
fragments. This sherd is tempered with this material. 
141.2 (2.5 X plane polarized light) Plagioclase
+ k-spar rock fragments (this sherd is tempered with only this
stuff). 
141.2 (2.5 X cross-polarized light) Same view as
plane polarized, but show the twinning of the plagioclase. 
142.15b (2.5 X plane polarized light) Planktonic
foraminifera (single round sphere to the upper left of centre is Orbulina).
A multi-chambered foram is shown in centre. Angular rock
fragments of plagioclase +/-
k-spar (upper right corner).
142.15b (10 X cross polarized light) Planktonic
foram (right) and plagioclase mineral grains (stripes are the
twinning). Both polysynthetic and Carlsbad twin laws shown in
these fragments.
143.2 (2.5 X plane polarized light) Rock and
shale fragments as temper (subangular to subrounded in grain
shape). 
143.2 (10 X plane polarized light) Closer view
of plagioclase + k-spar rock fragment (top), feldspar + amphibole
rock fragment (righ; the amphiboles are slightly pleochroic in a
green-brown colour range), k-spar mineral grain (left – with
the funny squiqqles and light yellow colour - this is a quartz
exsolution feature ). A small rounded shale fragment is directly
about this mineral grain.