Eagle Cave South Trench 2015: Profile Section 12

By Emily McCuistion

**This is the third of four blog posts showcasing a different Profile Section that was documented and sampled during the 2015 field season. Each of these Profile Sections has different sediment characteristics, artifacts, and ecofacts. Profile Section 12 is located further towards the dripline than Profile Sections 9 or 17 For a location map see 2015 Investigations at Eagle Cave.**

IMG_5961

Emily standing next to her poster at TAS.

Profile Overview

Profile Section 12 (PS12) is located centrally in the south trench wall of Eagle Cave at a point of transition from superior preservation (just behind the shelter’s dripline) to increasingly fragmented organics and compacted sediments near the back of the shelter. The profile is characterized by dense fire cracked rock (FCR) from earth oven cooking capping alternating deposits of fibers (plant remains), FCR, and latrine deposits.

PS12

Profile Section 12 prior to sampling.

PS12_strats

Stratigraphic boundaries of Profile Section 12

Strat Descriptions

(Listed top to bottom)

  • S174: Disturbed, dominated by dense FCR.
  • S177: Dense FCR with ash and some fiber.
  • S229: Thin lens of burned fiber.
  • S230: Thin lens of “ashy” silt with little FCR.
  • S231: Thin lens of FCR in loose, “ashy” silt.
  • S232: Charcoal stained “ashy” silt; few FCR.
  • S233: Decomposed fibers in a silty matrix.
  • S234: Fiberous; possibly urine compacted.
  • S235: Lens of fiber and coprolites in silt matrix, extends only ~40cm into exposure. S272: Compact with irregular topography and some fibers; possibly urine compacted; overlaying or intermixed with FCR.
  • S236: Semi-compact “ashy” silt with few FCR, some fibers likely intrusive from S234.
  • S241: Small patch of fiber and coprolites.
  • S237: Dense FCR in a loose “ashy” silt.
  • S238: Thick fiber layer with scattered FCR.
  • S239: Originally thought to be intact but found to be disturbed during excavation.
  • S240: Originally thought to be intact but found to be disturbed during excavation.
  • S285: White “ashy” silt with crumbly limestone and FCR

 

Profile Sampling

Two sampling columns (Units 57 and 64) were excavated by stratigraphic layer (strat) in the eastern 2/3rd of the profile. When sampling strats individually was not feasible, several strats were combined into a unit-layer.

PS012

Layers excavated in sampling column units 57 and 64, re-projected onto PS12. Layer boundaries are based on the east-west midline of the units.

Data Summary

The graphs below present data from the sampling columns (Units 57 and 64). Note that data correlate imperfectly in the sampling columns as some strats were lumped together into layers during excavation, and other strats were not present in both sampling columns. An asterisk indicates that a strat was sampled individually in one unit, but was not sampled individually in the unit-layer listed in parenthesis. For instance, within Matrix volume, S229 and S232 were collected individually in Unit 64, but S230 was not present in Unit 64. In Unit 57, S229, S232, and S230 were collected as part of Layer 2.

PS12_MatrixVolume

Matrix Volume does not include FCR >1 inch. No Matrix collected from S174, S177, or S239.

PS12_FiberMass

Fiber mass is from ½” sieve.

PS12_FCRMass

FCR mass includes only FCR >1 inch. FCR data was not taken for S174.

PS12_Debitage

Lithic debitage count is from ½” sieve.

Artifacts

Artifacts found in sampling PS12 include a bone tool, a groundstone fragment, a wooden artifact with cut marks, 6 fiber knots and 2 strands of cordage, 2 biface fragments, 2 cores, 8 modified flakes, 3 painted pebbles, 19 manuports, 2 quids, 45 paleofeces or fragments of paleofece, and abundant faunal and botanical remains.

PS12_Artifacts

The Future of PS12!

Anticipated data and study includes radiocarbon dating, faunal, botanical, coprolite, pXRF, micromorph, residue and artifact analysis. PS12 has an important role to play in understanding site use, formation and preservation processes at Eagle Cave.

PS12_Excavators

Dr. Kevin Hanselka (left) annotates PS12 and Emily (right) excavating one of the two sampling columns in PS12.

**A PDF version of the poster is available here: McCuistion_TAS2015_PS012_FINAL

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s