Radiocarbon Ages from the Lubbock Lake Site: 1981-1984

Abstract

Forty-eight additional radiocarbon ages became available for Lubbock Lake (Southern High Plains of Texas) during the period 1981-1984. A new but unreliable radiocarbon age is available from Stratum 1 (deposition ending about 11,000 years B.P.; Clovisage occupation). Thirty-three new radiocarbon ages are available from Stratum 2 and suggest the following refinements to the previously established radiocarbon chronology for the deposit: (1) the initial phase of lacustrine (diatomite) deposition lasted from 11,000 to about 10,500 years B.P. (early Folsom occupation); (2) the first cycle of marsh (organic-rich clay) sedimentation occurred between about 10,500 and 10,200 years B.P. (late Folsom occupation); (3) the substrata 2A-2B contact is not time-transgressive and dates to 10,000 years B.P. or a little less (Plainview occupation); (4) near-shore deposits (substratum 2s) are facies of all or portions of substrata 2A and 2B; (5) eolian sediments (substratum 2e) began to accumulate by 9000 years B.P. (early Firstview occupation); and (6) the Firstview Soil developed in upper substratum 2B beginning about 8500 years B.P. (Firstview occupation) and ended as late as 6300 to 6200 years B.P. (early Archaic occupation), which also would be the age for the beginning of Stratum 3 deposition. Both new and previously reported radiocarbon ages from upper Stratum 3 and lower Stratum 4 suggest that the Yellowhouse Soil formed in Stratum 3 along the valley margins during the period 5500-5000 years B.P. (middle Archaic occupation). At this time along the valley axis, Stratum 3 was eroded and then substratum 4A was deposited as a result of increased spring activity. New radiocarbon ages from charcoal further document human activity at Lubbock Lake during the Protohistoric (Garza) period. The additional radiocarbon ages from Lubbock Lake strengthen the position of the site as one of the best-dated sites in North America.