Lincoln Boyhood
Historic Resource Study
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CHAPTER II:
Environmental Overview

The historical record is as much a product of natural forces as of human endeavors. In much the same way, the extant landscape displays the interwoven influences of cultural and natural components in an ever-evolving relationship. In order to understand patterns of prehistoric human occupation in Spencer County, the natural environment of southern Indiana must be considered. Human societies at all levels of complexity are linked to the natural environment in a systemic or ecological relationship. This relationship can best be understood as the differential use of available resources, coupled with the strategies employed for exploitation of those resources. Environmental constraints work to define the set of settlement and subsistence options available to a particular social group. These include proximity to water, climactic patterns, access to lithic resources, and the presence of game and edible plants. Parameters such as these further affect site selection for settlements and influence the likelihood of the site's subsequent preservation. Only sites preserved through a combination of environmental, locational, and geographic factors remain sufficiently intact to yield information concerning prehistoric peoples. Consequently, the information available about patterns of human occupation in a given area is shaped both by the types of societies occupied the area and the contemporary and subsequent environmental conditions present at the site.

PHYSIOGRAPHY-GEOMORPHOLOGY

Spencer County is located in southwestern Indiana, approximately 150 miles south of Indianapolis and 40 miles east of Evansville. It is bounded on the west by Warrick County, on the north by Dubois County, and on the east by Perry County. The 37-mile southern boundary is formed by the Ohio River. Spencer County is approximately 400 square miles in area. [1]

This county lies within the Wabash Lowlands physiographic unit, the largest and westernmost unit in southern Indiana (Figure 2). It is situated south of the Illinoian and Wisconsin glacial boundaries. During the Wisconsin Age (Late Pleistocene), the tremendous volume of water carried by the Wabash River created a lake that covered much of southwestern Indiana. Depositions dating from this era are responsible for the present topography of broad aggraded valleys separated by low, rolling hills. As a result, with the exception of the northeastern section, topographic relief in Spencer County is not great, with elevations generally ranging between 338 and 660 feet above sea level. In these unglaciated areas, the soil is thin and easily worn away, particularly in comparison to the soil stratigraphy in the northern half of Indiana. [2]

map of Indiana
Figure 2: Map of Indiana Showing Physiographic Units and Glacial Boundaries (Schneider, 1966: 41) (click on image for an enlargement in a new window)

In southern Indiana, the Ohio River is bordered by bottom lands and floodplains as much as three-and-a-half miles in width. During prehistoric times, extensive swamps and marshes paralleled the river. Fully one-quarter of Spencer County's area historically was dominated by marshy bottomlands and floodplains. A few shallow lakes were present as well, with the largest being Willow Pond, located in east-central Luce Township. Sand and silt ridges were interspersed among the swamps, and likely were dry except during periods of flooding. Kellar's archaeological survey of Spencer County suggests that many of these ridges were locales for aboriginal occupation. [3]

Presently, with the exception of the Ohio River, Spencer County does not have any major waterways. Little Pigeon Creek and Anderson River form the western and eastern boundaries, respectively, of the county and both are comparatively modest streams. A number of small brooks exist, such as Big Sandy, Little Sandy, and Crooked creeks, but these often are dry during summer months. Dredging and draining are believed to have altered a number of stream courses. Deforestation of the area during the nineteenth century and subsequent agricultural practices also are likely to have contributed to changes in drainage patterns. [4]

BEDROCK GEOLOGY

Spencer County is underlain by rocks of Pennsylvanian age (late Paleozoic Era), the youngest bedrock formations found in Indiana (Figure 3). The dip in the rock beds is generally to the west from the Cincinnati Arch. The stratigraphy is dominated by siltstones and shales, interbedded with limestone formations and coal beds. [5] Bedrock geology determined the various lithic resources available for utilization by Paleoindian cultures, the types of soils in the area (which were significant to agricultural activity), and topography. In more recent times, the proximity of the coal beds to the surface has resulted in the strip mining of much of the county.

map
Figure 3: Map of Indiana Showing Bedrock Physiographic Units (Gutschick, 1966:54) (click on image for an enlargement in a new window)

LITHIC RESOURCES

Several limestones crop out within and near Spencer County that contain chert. These cherts include Holland and Lead Creek. Holland chert is a high quality blue-gray chert that crops out in southcentral Dubois and northern Spencer Counties. It was utilized by prehistoric peoples during all cultural periods for use as tools, blades, and spear points. Lead Creek has also been known as Lieber and "the black chert beneath the Mariah Hill coal seam." It is a poor to medium quality fossiliferous chert found in residual contexts in much of Spencer County. Other chert resources in the vicinity include Ditney chert in Warrick County, Haney chert in Perry, Crawford, and Orange Counties, and Derby chert in Perry County. All of these are of medium quality. The high quality Wyandotte chert crops out some 35 miles to the east, along the Crawford and Harrison County border. [6]



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Last Updated: 19-Jan-2003