Stable isotope (δ18O,δ13C) results of speleothems from Angelica Cave (central Brazil)

• Main Authors: Wong, Minn Lin, Wang, Xianfeng, Latrubesse, Edgardo M, He, Shaoneng, Bayer, Maximiliano
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2021
• Subjects: Sample code/label; AGE; δ18O, carbonate; δ13C, carbonate; Multiple investigations; Isotope ratio mass spectrometer IRMS with a GasBench; Dee; North Atlantic
• Online Access: https://dx.doi.org/10.1594/pangaea.938676; https://doi.pangaea.de/10.1594/PANGAEA.938676

Here we present a speleothem oxygen isotope (δ18O) and carbon isotope (δ13C) record from Angelica Cave in central Brazil (13.40°S, 46.23°W, ~585 m above sea level). The record is based on three stalagmite samples, AG1, AG2 and AG4. Ages of the samples were constrained by high-precision U-Th disequilibrium dating performed using a Thermo‐Fisher Scientific Neptune Plus multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS). The three samples have a combined temporal coverage of 0.1-6.8 kyr BP, roughly spanning the mid-to-late Holocene. Stable isotope values were measured using a GasBench coupled to a Delta-V isotope ratio mass spectrometer (IRMS) system. Angelica δ18O and δ13C values display an overall relatively flat trend with time. The Angelica Cave underlies the core of the South Atlantic Convergence zone (SACZ). The δ18O record can therefore be interpreted as proxy for SACZ rainfall intensity. The relatively flat δ18O trend over the past 6.8 kyr BP suggests that SACZ rainfall intensity remained largely invariant during the mid-to-late Holocene, despite the rising South Hemisphere summer insolation and increasing monsoon strength in the core South American Summer Monsoon zone. The Angelica δ18O record also shows no clear expression of abrupt North Atlantic events, such as the Little Ice Age, Medieval Climate Anomaly and Bond Events. : Age in years before present (BP), where BP=1950 ADδ18O and δ13C are reported in a delta notation, with respect to Vienna Pee Dee Belemnite (VPDB), where δ18O = [(18O/16O)sample/(18O/16O)standard – 1] × 1,000‰ and δ13C = [(13C/12C)sample/(13C/12C)standard – 1] × 1,000‰