LOWER EOCENE HYPERTHERMAL AND TRANSGRESSIVE EVENTS AS REVEALED FROM STABLE ISOTOPIC ANALYSIS OF LIGNITE BEARING COASTAL DEPOSITS FROM KUTCH BASIN, WESTERN INDIA
Our study shows presence of seven negative CIEs across the entire section where the lowermost CIE with a δ13COM magnitude of -30.6‰ can be attributed to the PETM. δ13CAMB followed a similar pattern like that of the δ13COM. The δ13CBC from the shell carbonate shows the variation in the productivity whereas δ18OBC reflects fluctuations in terms of oxygen isotopic ratios of water composition as a result of variations in temperature, and mixing between seawater and freshwater.
The lignite bearing succession with profuse plant debris and pyrite represents a sheltered environment. The upper part of the succession bearing well-preserved marine molluscs indicates incursion of the sea in this coastal lagoon. It was preceded by a CIE. This suggests the presence of a causal link between the hyperthermal and the transgression.
Zachos, J. C., McCarren, H., Murphy, B., Röhl, U., & Westerhold, T. (2010). Tempo and scale of late Paleocene and early Eocene carbon isotope cycles: Implications for the origin of hyperthermals. Earth and Planetary Science Letters, 299(1-2), 242-249.