Planktonic foraminiferal quantitative analysis across the Campanian/Maastrichtian boundary at the Pondicherry area, Cauvery Basin, Southern India

• Published in: Geological Journal
• Main Authors: Nallamuthu, Malarkodi, Hussein Orabi, Orabi, Chandrashekhara Shashtri, Bhargava Sharma, Srinivas, Chethan Kumar
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2021
• Subjects: Planktonic foraminifera
• Online Access: http://dx.doi.org/10.1002/gj.4322; https://onlinelibrary.wiley.com/doi/pdf/10.1002/gj.4322; https://onlinelibrary.wiley.com/doi/full-xml/10.1002/gj.4322

The late Campanian/Maastrichtian succession exposed at Pondicherry area affords one of the finest exposed marine sections in Cauvery Basin is examined for their foraminiferal contents. The biostratigraphic distribution of 71 species of planktonic foraminifera has been used to diagnose 11 planktonic zones and subzones and correlated to the worldwide bioevent. During the late Campanian, a great transgression event occurred associated with the global warming (CF8b zone) trend indicated by large double‐keeled foraminifera ( Globotruncana aegyptiaca Nakkady) of oligotrophic conditions. The latest zone CF4 records a sharp decrease in Planktonic/Benthic (P/B), globotruncanids, rugoglobigerinids and heterohelicids implying a fall of sea level.