Abstract

δ18 O values in speleothems have been utilized to document past changes in South American monsoon intensity. However, changes in regional vegetation and ecosystems have not been part of this discussion, and other cave proxies such as speleothem δ13 C values, a useful proxy for vegetation reconstruction, have been neglected due to interpretive complexities. Here we report δ13 C values and 87 Sr/86 Sr ratios in stalagmites, together with XRF-derived elemental chemistry, δ13 C org values and carbon content from a sedimentary profile from the same cave where the stalagmites were collected. In combination with a previously published δ18 O record, this enables us to clarify climate and environmental shifts that occurred between the Last Glacial Maximum and the Holocene in central South America. We show that vegetation was sparse during the last glacial period in spite of a previously inferred strong monsoon, and that changes in atmospheric pCO2 combined with local hydrological and temperature feedbacks may have determined vegetation development during this time.

Document Type

Article

Publication Date

2019

Notes/Citation Information

0012-821X/© 2019 Elsevier B.V. All rights reserved.

Digital Object Identifier (DOI)

https://doi.org/10.1016/j.epsl.2019.115717

Funding Information 

This work was supported by the São Paulo Research Foundation (FAPESP) (grants 2016/00299-4 to I.K.; 2012/03942-4, 2014/10095-1, 2015/08351-2, 2016/15807-5, 2017/23687-2 and 2018/12285-3 fellowships to V.F.N.; 2016/24870-2 fellowship to P.J.; 2012/50260-6, 2013/50297 and 2017/50085-3 PIRE NSF- FAPESP to F.W.C.), the US National Science Foundation (NSF) grants AGS-1303828 and OISE-1743738 to M.V., NSF-AGS 1602962 to C.I.W. and 1103403 to R.L.E. and H.C., as well as German Research Foundation grants SCHO 1274/9-1 and SCHO 1274/11-1 to D.S.

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