Holocene (~4.5-1.7 cal. kyr BP) paleoenvironmental conditions in central Argentina inferred from entire-shell and intra-shell stable isotope composition of terrestrial gastropods
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Date
2014
Journal Title
Journal ISSN
Volume Title
Publisher
SAGE
Sage Publications LTD
Sage Publications LTD
Abstract
The isotopic fingerprint of terrestrial gastropods has been increasingly used as a credible natural paleoenvironmental archive. Most published work has used this proxy at tropical and temperate latitudes of the Northern Hemisphere, and focused on entire-shell analysis. The present study provides entire-shell and intra-shell isotopic profiles to infer average and seasonal late Holocene environmental conditions in central Argentina (30°S). Shells of Plagiodontes daedaleus (Gastropoda: Odontostomidae) were retrieved from the Alero Deodoro Roca–Sector B site, one of the few archaeological sites in central Argentina rich in shells collected by pre-Hispanic hunter-gatherer groups. Ancient entire shells exhibited values that were ~2.5‰ higher in δ13C and ~1.8‰ higher in δ18O than modern individuals, pointing to higher abundance of C4 plants and overall drier conditions (lower relative humidity and/or higher rain δ18O) during 4.5–1.7 cal. kyr BP than today, in agreement with published regional proxies. Intra-shell isotopic profiles suggest that modern and fossil specimens deposited their shells throughout two-to-three summer/winter cycles. Intra-shell δ18O values varied ~5‰, matching with the seasonal variation of rain δ18O values. The extent of seasonality was similar during 4.5–1.7 cal. kyr BP and today. Intra-shell δ13C values varied ~2–3‰ and did not portray distinct seasonal cycles, depicting minimal seasonal variations in the snail diet. This work illustrates that South American terrestrial gastropods have great potential for paleoenvironmental studies.
Description
Keywords
Argentina, Holocene, Ongamira, paleoenvironment, stable isotopes, terrestrial gastropods
Citation
Yanes, Y., Izeta, A. D., Cattáneo, R., Costa, T., & Gordillo, S. (2014). Holocene (~4.5–1.7 cal. Kyr BP) paleoenvironmental conditions in central Argentina inferred from entire-shell and intra-shell stable isotope composition of terrestrial gastropods. The Holocene, 24(10), 1193-1205. https://doi.org/10.1177/0959683614540959
Yanes, Y., Izeta, A. D., Cattáneo, R., Costa, T., & Gordillo, S. (2014). Holocene (~4.5–1.7 cal. Kyr BP) paleoenvironmental conditions in central Argentina inferred from entire-shell and intra-shell stable isotope composition of terrestrial gastropods. The Holocene, 24(10), 1193-1205. https://doi.org/10.1177/0959683614540959
Yanes, Y., Izeta, A. D., Cattáneo, R., Costa, T., & Gordillo, S. (2014). Holocene (~4.5–1.7 cal. Kyr BP) paleoenvironmental conditions in central Argentina inferred from entire-shell and intra-shell stable isotope composition of terrestrial gastropods. The Holocene, 24(10), 1193-1205. https://doi.org/10.1177/0959683614540959