Geomorphology and Archaeology of Carnegie Canyon Fort Cobb Laterals Watershed, Caddo County, Oklahoma

Summary

Downcutting of a small stream is currently threatening a county road within the Fort Cobb Laterals Watershed in Caddo County, Oklahoma. Stabilization plans propose the construction of Drop Structure 101, and the relocation of the road atop the dam.

A survey of the project area in February, 1981, located an historic homestead (34Cd-121) on the flanking slopes, and several hearth features, small quantitites of cultural materials, and portions of a human cranium within a deep canyon in the valley (34Cd-76). The present creek is incised 11 meters into the valley floor; however, core drilling along the proposed dam axis indicates that the valley fill is over 32m deep.

Geomorphic studies described in this report correlate stratigraphic sequences throughout the valley and determine the age and rate of deposition of sediments in the canyon. In addition, 24 molluscan species, 63 buried tree stumps, which were dated between 2600 and 3200 years ago, and carbonate deposits within some paleosol layers were available to develop a preliminary paleoenvironmental model of the valley during the last 3000 years. A predominance of buried juniper stumps suggests that the water table was several meters below the valley floor during a period 2600-3200 years ago. During this relatively dry period the rate of sediment deposition averaged approximately 0.8 cm per year, even though several minor paleosol horizons are present. Between 1000 and 2000 years ago, the water table rose nine meters and a perennial stream flowed through the canyon. Evidence for the high water table level is reflected in a fossil spring conduit, the presence of at least seven aquatic molluscan species, high carbonate precipitates on the canyon walls, and the development of a thick paleosol horizon believed to correspond to the Caddo County paleosol defined for Delaware Canyon. The sedimentation rate in the valley slowed to between one-third and one-tenth the former deposit rate. Subsequent alluviation and formation of a weaker paleosol have occurred unconformably over the Caddo County paleosol horizon. The deep canyon cutting is relatively recent, and the level of the present water table is apparently four meters below the level during formation of the Caddo County paleosol.

The present geomorphic studies were based on data within the deep canyon north of the proposed impact area. Most of these deposits will not be affected during project development. The presence of sand lenses and diluted paleosol horizons from lateral tributaries near the proposed dam axis indicated that this section of the canyon is not representative of the geomorphic trends necessary to successfully correlate the various stratigraphic units.

Archaeological studies focused on examining an early statehood period homestead site (34Cd-12l) within the proposed emergency spillway, and testing at several specific localities at prehistoric site 34Cd-76.

Archaeological examination of the historic locality (34Cd-12l) revealed that the area has experienced erosion with deflation of 60 cm of soil. Furthermore, the distribution of materials on the bedrock surfaces has been culturally altered. The dimensions of the cultural features were recorded. No further work is recommended for the site.

Several aspects of site 34Cd-76 were examined. A total of 32 one meter units were used to test the upper valley fill within the proposed borrow pit, near the dam axis and emergency spillway overflow areas along the east side of the valley. Excavations focused on a possible bison kill/butchering area, three exposed hearth features, a disarticulated deer skeleton, an area where fragments of human cranium were found, and a limited testing of the lower valley fill. In all instances, cultural materials were very sparse. The results of testing suggest that a diverse range of short term activities were conducted by different groups in the valley. Functional/temporal diagnostic materials were scarce; consequently, most occupations must be dated stratigraphically. Radiocarbon dates of A.D. 410+/-100 (Beta-3090), 440+/-100 B.C. (Beta-2622), and 530+/-50 B.C. (Beta-2623) from the hearth features and a series of twelve dates from buried tree stumps that grew in the valley between 670 and 1200 B.C. were obtained. These dates suggest that any accessible cultural materials in the valley would date no earlier than the late Archaic period.

Additional activity areas and features may be present at the site. Because of the logistical and financial constraints imposed by the depth of deposits and the small quantities of cultural materials present, no further excavations are recommended. This recommendation is in accordance with established federal guidelines (Advisory Council on Historic preservation 1980: 18, section B(2)a). Since other features or stumps may be exposed during the development of the project, an archaeologist should be present to monitor construction. Sites 34Cd-76 and 34Cd-121 are not considered to be eligible for nomination to the National Register of Historic Places.

Archaeological site 34Cd-244 within the same canyon was visited to monitor the extent of erosion. Previous excavations at this site were conducted by Archaeological Research Associates of Tulsa to remove human burials in conjunction with the development of Structure 2. The recent check revealed that the original bulldozer cut is presently an eight meter gulley, and additional human remains were located. An appendix by Archie Hood, Jr. in this report provides a reanalysis of all skeletal remains from the site.

Originally the information in this record was migrated into tDAR from the National Archaeological Database Reports Module (NADB-R) and updated. In 2014, as part of its effort to improve tDAR content, the Center for Digital Antiquity uploaded a copy of the document and further improved the record metadata.

This Resource is Part of the Following Collections

• National Archeological Database (NADB)

Keywords

Temporal Coverage

Radiocarbon Date: 510 to 310 (Beta-3090)

Radiocarbon Date: 540 to 340 (Beta-2622)

Radiocarbon Date: 580 to 480 (Beta-2623)

Spatial Coverage

Individual & Institutional Roles

Submitted To(s): US Department of Agriculture, Soil Conservation Service, Stillwater Office

Record Identifiers

NADB document id number(s): 2160490; 2160745

NADB citation id number(s): 000000011511; 000000011265

Notes

General Note: Originally this record was automatically added to tDAR from NADB. In 2014, a copy of the document was added and the record metadata was updated. There was a second record (tDAR id: 136512) for this document, which has been marked as "duplicate".

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