Late Quaternary climatic variability in northern Patagonia, Argentina ? information from modern and fossil shells of Amiantis purpurata(Bivalvia, Veneridae)

BAYER SOL; LARS BEIERLEIN; MORAN GISELA; DOLDAN, MARÍA DEL SOCORRO; MORSAN, ENRIQUE M.; BREY, THOMAS; MACKENSEN, ANDREAS; FARIAS, LAURA; GARCÍA, GERARDO ; GORDILLO, SANDRA

PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2020

0031-0182

Amiantis purpurata is a common warm-temperate water bivalve species distributed from southern Brazil tonorthern Patagonia, Argentina, which has a rich and well preserved fossil record in the San Matías Gulf (SMG)dating back to the late Quaternary. The main goal of this study is to check if A. purpurata shells qualify forbeing a new palaeoarchive of past marine conditions in South America. For this purpose, eleven specimens ofA. purpurata from different geological times (modern, Late Holocene and interglacial Late Pleistocene) wereused for a comparative analysis of stable oxygen and carbon profiles (δ18Oshell; δ13Cshell). We furthermorepresent the first in situ oxygen isotope values of seawater within SMG (δ18Owater). Using both information, wecalculated and reconstructed palaeowater temperatures for the Late Holocene and compared them to modernwater temperatures. Our findings indicate that A. purpurata records past environmental parameters such aswater temperatures on a seasonal scale and can therefore be considered a suitable candidate for futurepalaeoenvironmental reconstructions in Northern Patagonia. This study is the first step towards further stableisotope analyses on fossil A. purpurata shells, which will show whether and if so, to what extent, importantglobal climate events such as the Neoglacial (Early Holocene), the Hypsithermal (Middle Holocene) and theLittle Ice Age (Late Holocene) occurred in South America.