In:
Quaternary Research, Cambridge University Press (CUP), Vol. 63, No. 1 ( 2005-01), p. 31-44
Abstract:
Well-preserved aragonitic land snail shells ( Vallonia ) from late Pleistocene Eolian sediment in the Folsom archaeological site in New Mexico exhibit an overall decrease of δ 18 O PDB from maximum values of +2.7‰ (more positive than modern) to younger samples with lower average values of about −3.6‰ (within the modern range). The age of the samples (approximately 10,500 14 C yr B.P.) suggests that the decrease in δ 18 O may manifest climatic changes associated with the Younger Dryas. Some combination of increased relative humidity and cooler temperatures with decreased δ 18 O of precipitation during the times of snail activity can explain the decrease in shell δ 18 O. A well-known Paleoindian bison kill occurred at the Folsom site during this inferred environmental transition. Average δ 13 C values of the aragonite shells of the fossil Vallonia range from −7.3 to −6.0‰ among different archaeological levels and are not as negative as modern values. This suggests that the proportion of C 4 vegetation at the Folsom site approximately 10,500 14 C yr B.P. was greater than at present; a result which is consistent with other evidence for higher proportions of C 4 plants in the region at that time.
Type of Medium:
Online Resource
ISSN:
0033-5894
,
1096-0287
DOI:
10.1016/j.yqres.2004.09.010
Language:
English
Publisher:
Cambridge University Press (CUP)
Publication Date:
2005
detail.hit.zdb_id:
1471589-2
detail.hit.zdb_id:
205711-6
SSG:
13
SSG:
14