Response of trace and rare earth elements to environmental changes in a stalagmite from southern India for the last deglaciation

Abstract

Speleothems, particularly stalagmites are extensively used to reconstruct paleoclimatic and paleomonsoon changes by using stable oxygen and carbon isotopes along the growth profile of a stalagmite sample. Trace and rare earth elements (REEs) variations in stalagmites are widely recognized as indicators of past precipitation and local hydrology. The amalgamation of isotopic and trace element proxies in speleothems has been regarded as an important tool to infer past climate and hydro-chemical fluctuations. Current advancements in geochemical techniques have enabled us to generate high-resolution paleo-records of almost all trace and REEs from stalagmites. However, their assessment is dependent on numerous factors that control the formation of a stalagmite.Here we present a geochemical record from a well dated stalagmite (VSPM1) from a cave located in the southern India. The stalagmite grew between 15,610 and 13,160 yr BP as revealed by its StalAge modelled ages from eight U–Th dates. This study demonstrates significant variations in trace and REEs during the last deglacial time interval of 2100 years and suggests variations in drip water chemistry. The relative amount of trace elements in colloidal solutions originating from the soil organics and weathered particles of host dolomitic rock may have altered with climatic changes. It appears that trace and REEs of VSPM1 stalagmite have responded to fluctuations in Indian Summer Monsoon (ISM) intensity during the time interval of this study.