Laserfiche WebLink
• <br />Prehistoric land use patterns that primarily involved hunting and gathering practices <br />had little or no adverse affect on the local environment. Prehistoric camps most likely <br />occurred on the south-lacing benches above the river. The advent of coal mining in the early <br />1900's changed the study area dramatically. The narrow valley bottom was terraced to <br />accommodate housing and mining facilities, and the benches of adjacent mountain slopes <br />were flattened for storage. Presently, the valley bottom is used for farming and pasture. <br />Palcoclim:ttc <br />Reconstruction of paleoenvironmental conditions is essential to the understanding of <br />population movement and cultural change in prehistoric times (Euler et al. 1979). Changing <br />environmental conditions altered the exploitative potential of an area and put stress upon <br />aboriginal cultures by requiring adjustments in their subsistence patterns. To interpret <br />whatever changes are seen in tl~e archaeological record, an account of fluctuations in past <br />climatic conditions must be available or inferences must be made from studies done in <br />surrounding areas. Generally, only gross climatic trends have been established for western <br />North r\merica prior to 2000 B.P. (Anicvs 1955; Nlehringcr 1967; Madsen 1932; Wendlund <br />and Bryson 1974; Peterson 1931). Scientific data derived from investigations of prehistoric <br />cultures and geoclimatic and bioclimatic conditions on the southern Colorado Plateau over <br />• the past two millennia have achieved a much greater decree of resolution (Dean et al. 1935) <br />A study by Berry and Berry (1936:313-314) summarizes the gross climatic episodes <br />of the Colorado Plateau and Basin and Range provinces over the past 13,000 years, as <br />determined from radiocarbon-dated pollen samples. Between 11,000 and 3,000 B.C., <br />conditions shifted from glacial to non-glacial; i.e., there was an overall decrease in effective <br />moisture and an increase in temperature. The ensuing pre-BorealBoreal period (3000-6500 <br />B. C.) brought cooler, drier conditions to [he region. The Atlantic period (6500-3100 B.C.) <br />was one of complexity. In large part, it corresponds to Antev's Altithermal, but evidences <br />two cotnparativcly short phases (6500-5500 and 4750-3950 B.C.) of increased coolness. <br />Between 3100 and 300 B.C., the Sub-Boreal episode saw an increase in effective <br />moisture and, on the Plateau, a corresponding increase in pinyon pine forest. Stigcr (1931: <br />107-108) suggests pinyon pine disappeared from the Gunnison Basin during this time and <br />was replaced, in part, by ponderosa pine. <br />The Sub-Atlantic period (300 Q.C.-A.D. 400) was mainly a time of drying and <br />warming and, on the Plateau, contraction of the pinyon forest, although warm wet conditions <br />prevailed toward the end of this period. A brief, cool dry phase occurred early (r\. D. 350- <br />450) in the Scandic/ Neo-Atlantic (A. D. 400-1 100), but the remainder of this episode is <br />characterized as warm and wet. A period of cool, dry conditions--the Pacific episode-- <br />. followed and lasted approximately 600 years. <br />3 <br />