Laser-based stable isotopic analyses of carbonates to obtain high-resolution climatic signals and its application to understand Early Harappan climate

A high-resolution isotopic analysis of biogenic carbonates from Dholavira, a UNESCO World Heritage Site and ancient Harappan city, reveals that the region experienced more favorable climatic conditions during the Early Harappan period (4.6–5.2 thousand years ago) than today's arid environment. The study, using laser-based stable isotopic techniques, examined otoliths from estuarine catfish and bivalves to reconstruct monthly climatic variations, including temperature, salinity, and precipitation patterns. Findings indicate a glacial-fed river system mixed with seawater in an estuarine setting during monsoonal seasons, while winter months saw evaporative enrichment due to reduced river discharge. This suggests that Dholavira's agricultural society thrived under conditions of higher riverine flow and precipitation, contrasting sharply with the current semi-arid climate. The research highlights the potential of sclerochronological analyses in reconstructing past environmental dynamics linked to cultural evolution.

Sengupta, T., Deshpande-Mukherjee, A., Bhushan, R., & Sarkar, A. (2022). Laser-based stable isotopic analyses of carbonates to obtain high-resolution climatic signals and its application to understand Early Harappan climate. https://doi.org/10.5194/egusphere-egu22-254