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Appendix A (cont.)
Backhoe Trench 3 (Figure
A11)
Section Located 1.2 m Southwest of Stadia Station 53; surface is machine
cut.
Unit
1
2
3
(Bedrock) |
Thickness (cm)
5
25.4
60+ |
Description
Sand, loose (modern) - brown, very fine to coarse grained, poorly sorted,
clayey, silty.
Ak soil horizon - sand, massive, light gray, very fine to medium grained,
±10% coarse sized; poorly sorted; ±10% randomly scattered
0.5-2.5-cm-long pebbles; silty, clayey; reacts with HCl; basal contact
gradational over 7.6 cm.
R soil horizon - sandstone bedrock, weathered. |
Section Located 1 m Southwest of Stadia Station 54; surface is machine
cut.
Unit
1
2
3
4
5
(Bedrock) |
Thickness (cm)
8
22
51
104
20+ |
Description
C soil horizon - loose sand.
Ck soil horizon - sand, massive; brown, very fine to medium grained,
silty, clayey; ±10% randomly distributed pebbles (0.5-5.0 cm), slight
reaction with HCl.
Ak soil horizon - sand, massive; light gray, arkosic, fine to medium
grained, silty, clayey (±30%); contains ±7% randomly distributed
pebbles (0.5-2 cm); slight reaction with HCl.
Bk soil horizon - sand, massive; fine to medium grained, silty, clayey
(±30%); contains ±7% randomly distributed pebbles (0.5-2.0
cm); slight reaction with HCl.
Rbk soil horizon - bedrock, sand, massive; medium grained, well sorted,
"loose," 7±% random pebbles (1-2 cm long); CaCO3
cement (Stage II). |
Stadia Station 55; surface is machine cut.
| Unit |
Thickness (cm) |
Description |
| 1
2
3
4 |
5
41
66
80+ |
Sand, loose (modern).
Ck-Ak-Ck2 soil horizons - sand, massive; fine-grained, well-sorted,
some medium-sized grains, silty, clayey (±40%); moderate reaction
with HCl. A ±13 cm thick weak, light gray, pedogenic A horizon is
present at the middle (center) of the unit.
2Ak soil horizon - sand, massive; very-fine to fine-grained, ±10%
medium -to-coarse grains, silty, clayey; ±15% random pebbles (0.5-2.5
cm long).
Bk soil horizon - massive sand as above; contains ±15% pebbles
(0.5-3 cm long); pebbles are completely coated with CaCO3. |
In Trench 3, all sediment above bedrock is CS. All pebbles are rounded
and elongate. The sediment in that portion of Trench 3 lying northeast
of Stadia Station 53 has been highly disturbed by earthmoving machinery.
A ±1 m thick veneer of loose, "machine churned" sediment overlies
a machine-cut bedrock surface. Unit 3 was "scraped up" downslope and redeposited
by machinery in this area. Units 1 and 4 correlate with the same numbered
units present between Stadia Stations 41-45 in Trench 1.
Backhoe Trench 4 (Figure
A12)
Stadia Station 62
| Unit |
Thickness (cm) |
Description |
| 1
2
3
4 |
10
19
37
107+ |
Sand, loose (modern).
Ck soil horizon - sand, massive; medium-grained plus silt and very-fine-grained
fraction; few pebbles in upper portion; lower 10 cm of unit contain ±20%
pebbles (0.5-2.5 cm long).
Ak soil horizon - sand, gray, massive; fine to medium-grained, ±5%
granule-sized grains; ±20% pebbles (±1 cm long), silty, clayey.
R soil horizon - bedrock (sand). |
Unit 1 (loose sand) is present at surface throughout trench. Unit 2
is similar throughout trench; sand contains pebble lenses (1.5-3.0 cm thick)
in lower half. Unit 3 is 37-108+ cm thick, rests on bedrock throughout
trench, has a gray color, is composed of silty, clayey, poorly sorted,
fine to coarse sand with 20-25% randomly distributed, rounded pebbles (0.5-3.0
cm long); pebbles are coated on bottoms with thin film of CaCO3.
Backhoe Trench 5
Trench 5 lies within an area in which the surface has been impacted
by machine blading. An ±80 cm thick veneer of "churned" Quaternary
sediment overlies bedrock in the northern half of the trench. A correlative
of Unit 3 (A horizon) that is present in adjacent Trench 4 overlies bedrock
in the southwestern half of the trench. The thickness of Unit 3 at Station
63 is 28 cm. It is overlain by 18 cm of sediment, correlative with Unit
2 in Trench 3. Units 2 and 3 are CS sediment.
Backhoe Trench 6 (Figure
A7)
Section C, Located 4 m Northeast of Stadia Station 92
| Unit |
Thickness (cm) |
Description |
1
2
3
4 |
8
22
28
67
18+ |
A soil horizon - "grass root" zone,
lithology as below.
C soil horizon - sand (CS), massive; grayish brown (5YR2/2); very fine
to coarse grained, poorly sorted; contains ±30% dispersed 0.2-0.5
cm long fragments of coal clinker.
Ck soil horizon - ephemeral-stream sediments; composed of gravel lenses,
2-3 cm thick and 30-95 cm long; lenses consist of granule-sized (0.2-0.5
cm) grains ("pea gravel"). Lenses are interbedded with sand, fine- to medium-sized
with ±10% granule-sized grains; contains silt and clay fractions.
Ak soil horizon - ephemeral-stream deposits, consists of gravel lenses,
1-1.5 m long, 3-5 cm thick that are composed of 1-3 cm long clasts. Gravel
lenses are interlayered with lenses of sand, fine to medium grained with
silt and clay fractions; an anomolous CaCO3 concretion (18 x
11 cm) is present 28 cm above base of unit. The matrix of Unit 3 has only
slight reaction with HCl.
2Ck soil horizon - gravel, yellowish brown (10YR6/2), granule-sized
clasts. |
Section B, Located 5.8 m Northeast of Stadia Station 92
| Unit |
Thickness (cm) |
Description |
1
2
3
4 |
7
31
20
30
58+ |
A soil horizon - "grass root" zone,
lithology as below.
C soil horizon - CS, consists of sand, massive, fine to coarse grained,
poorly sorted, with ±30% pebbles (0.5-5.0 cm long); pebbles occur
both dispersed and segregated along vague horizontal bands. The bottom
7.6 cm of unit is gray in color and contains ±5% dispersed 0.3-3.0-cm-long
coal fragments, a glass bottle fragment occurs 4 cm from bottom of the
unit. This coal-bearing horizon is 1.5 m long. A similar occurrence of
coal fragments is present at the base of Unit 1, at a point located 4 m
northeast of this measured section.
Ck soil horizon - ephemeral-stream sediments; at points located 55 and
71 cm northeast of this section, there are occurrences within sand of "pockets"
composed of coarse- to granule-sized coal fragments. The closest concentration
of coal fragments measures 3 x 3 cm and lies 17 cm below top of Unit 2,
while the other measures 5.5 x 2 cm and is located 11 cm below the top
of Unit 2.
Ak soil horizon - superimposed on ephemeral-stream sediments.
2Ck soil horizon - gravel lenses. |
Units 1-4 are traceable throughout most of Trench 6. Unit 1 is present
throughout the trench, while Units 2-4 punch out in the northeast portion
of the trench. Units 1 and 2 display transitions from CS to ephemeral-stream
sediments in a downslope direction. Units 3 and 4 are ephemeral-stream
deposits throughout the trench, though 4 exhibits a transition from gravel
to laminated, sandy clay in an upslope direction.
Units 1 and 2 date to the historical period. Unit 1 contains randomly
distributed bottles, bottle fragments, and tin cans. Other artifacts, including
a corset stay, were noted. These artifacts are pre-1900 in age (Douglas
Scott, personal communication 1992). Dispersed coal fragments are also
found in Unit 1. Two small, separated concentrations of coal fragments
are present in Unit 2. Other artifacts were not noted in Unit 2.
Units 3 and 4 are prehistoric in age and probably correlate with the
same numbered units in the northeast end of Trench 1. Units 3 and 4 are
pedogenic horizons that collectively form a Mollisol.
Backhoe Trench 7
Backhoe Trench 7 was excavated into the base of the riser between P1
and T2. It lies 260 m northeast of Site 48LA277 (Figures
A3, and A5-A6). This
shallow (±70 cm), 5.5-m-long trench lies at the bottom of a southwest-draining
draw, the contents of which was apparently "cleaned out" by a bulldozer,
leaving only 40 cm of pebbly sediment above bedrock. The bottom of the
draw is now grassed over.
Backhoe Trench 8 (Figure
A8)
Stadia Station 157
| Unit |
Thickness (cm) |
Description |
1
2
3 |
55
28
61+ |
Abt soil horizon - clay, (±70%),
massive; brownish gray (5YR4/1); sandy, very fine to fine grained, ±10%
medium sized; few 0.5-2.0-cm-long, isolated pebbles (<5%); columnar
pedogenic structure (planes 1.9-5.0 cm apart); continuous clay skins on
peds.
Btk soil horizon - clay, massive; brownish gray (5YR2/2); sandy, fine
to medium grained, few coarse grains; columnar pedogenic structure; prominent
continuous clay skins on peds. Stage II CaCO3 development, white
carbonate filaments decrease downward in abundance.
Bk soil horizon - clay/sand mixture (approximately 50/50), massive;
sand content is fine grained, well sorted. Displays Stages I and II CaCO3
filament development. |
Station B, Located 1.5 m Northeast of Stadia Station 157
| Unit |
Thickness (cm) |
Description |
| 1
2
3
4
5
(Bedrock) |
46
37
44
18
17+ |
Abt soil horizon - same lithology
as at Stadia Station 157
Btk soil horizon - same lithology as at Stadia Station 157
Bk soil horizon - same lithology as at Stadia Station 157; basal contact
is transitional over an 18-cm interval
2Bk soil horizon - sand, massive; pale orange (10YR5/4); fine grained,
very well sorted with some granule-sized (0.2-0.5 cm) grains; <10% isolated,
random pebbles that are 2-8 cm long; pebbles are completely covered by
CaCO3.
Rbk soil horizon - sand, massive; pale orange (10YR8/2), arkosic, (Bedrock)
very-fine to fine-grained, very-well-sorted, few granule-sized grains;
very clayey (approximately 40-60%); white CaCO3
filaments. |
At Stations D and E (see cross section ) Unit
4 has prominent (Stages II and III), white, CaCO3 cement in
very-fine to fine-grained sandy matrix. Pebbles (2.5-8.0 cm long) are completely
covered with CaCO3
film.
Backhoe Trench 9 (Figure
A10)
Stadia Station 104; surface is machine cut.
| Unit |
Thickness (cm) |
Description |
1
2
3
4 |
30
19
7.6
43+ |
C soil horizon - clay, massive; dusky
brown (5YR3/2); sandy (±25% sand, fine to medium sized), blocky
pedogenic structure, moderate reaction with HCl.
2C soil horizon - sand, laminated; yellowish brown (10YR5/2), very-fine-grained,
very-well-sorted, <5% random, medium-sized grains, ±35% clay;
strong reaction with HCl.
Ak soil horizon - lithology as in Unit 2, brown (5YR5/1), weak reaction
with HCl.
3C soil horizon - loose, arkosic; interbedded with gravel lenses; pale
yellowish brown (10YR6/2), horizontal lenticular bedding; sand is predominantly
medium to coarse grained, fair sorting; contains zones of 0.2-0.5-cm-sized
grains (granule) that grade laterally to 0.5-1.0-cm-sized clasts. Unit
contains gravel lenses (±70% cm long, 2.5-8-cm thick) that contain
±20% pebbles that are 6-8 cm long; weak reaction with HCl. |
Unit 1 dates to the historic period. It contains horizontal, artifact-bearing
horizons that contain flattened, rusted tin cans, the rubber heel of a
woman's shoe, metal scraps, and pieces of wire. The sediment in Unit 1
was evidently deposited as a result of earthmoving, compacting, and smoothing
by machinery. Units 2-4 are composed of fluvial, braided stream sediments.
A fluvent soil is superimposed on Unit 3.
REFERENCES CITED
Albanese, John P.
-1991 The Geoarchaeology of the Eastern Powder River Basin. Report
submitted to the State Historic Preservation Office, Wyoming
Archives, Museums, and Historical Department, Cheyenne.
Albanese, John P., and Michael Wilson
-1974 Preliminary Description of the Terraces of the North Platte River
at Casper Wyoming. In Applied Geology and Archaeology: The
Holocene History of Wyoming, edited by M. Wilson, pp. 8-18. Report
of Investigations No. 10. Geological Survey of Wyoming, Laramie.
Anderton, John B.
-1990 Soils, Paleoenvironments, and Geoarchaeology of Selected Sites
near Pine Bluffs,Wyoming. Master's thesis, Department of Geography
and Recreation, University of Wyoming, Laramie.
Connor, Melissa A.
-1993 1991 Test Excavations at 48LA277: A Plains Woodland Site on
Crow Creek, Wyoming. National Park Service, Midwest Archeological Center,
Lincoln, Nebraska.
Frison, George C.
-1991 Prehistoric Hunters of the High Plains. 2nd ed. Academic
Press, New York.
Love, J. D., and Ann Coe Christiansen
-1975 Geologic Map of Wyoming. U.S. Geological Survey, Washington,
D.C.
Soil Conservation Service
-1975 Soil Taxonomy: A Basic System of Soil Classification for Making
and Interpreting Soil Surveys. United States Department
of Agriculture, Washington, D.C.
Stevenson, Abe, Michael D. Lloyd, and Lionell
Joseph
-1983 Soil Survey of Laramie County, Wyoming, Eastern Part.
USDA Soil ConservationService, in cooperation with the Wyoming Agricultural
Experiment Station, University of Wyoming, Laramie.
Tetra Tech, Inc.
-1987 Southeastern Wyoming Prehistory, vol. 1. Peacekeeper Program
Cultural ResourcesTechnical Report No. 3.
 Appendix
A tables and figures
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