87Sr/86Sr anomalies in Late Cretaceous-Early Tertiary strata of the Cauvery basin,south India: Constraints on nature and rate of environmental changes across K-T boundary |
| |
| Authors: | Mu Ramkumar Doris Stüben Zsolt Berner Jens Schneider |
| |
| Affiliation: | (1) Institut für Mineralogie Geochemie, Universität Karlsruhe, 76128 Karlsruhe, Germany;(2) Present address: Department of Geology, Periyar University, Salem, 636011, India;(3) Department of Geological Sciences, Princeton University, Princeton, NJ, USA |
| |
| Abstract: | The Ariyalur-Pondicherry sub-basin of the Cauvery basin comprises a near complete stratigraphic record of Upper Cretaceous-Lower Tertiary periods. Earlier studies have documented variations of clay mineral assemblages, change in microtexture of siliciclasts and many geochemical and stable isotopic anomalies far below the Cretaceous-Tertiary boundary (KTB) in these strata. This paper documents the occurrences of two positive 87Sr/86Sr anomalies preceding K-T boundary in this basin and discusses plausible causes. Analysis of trace elemental and stable isotopic profiles, sedimentation history, petrography and mineralogy of the rocks reveal that while both the anomalies may be due to increased detrital influx caused by sea level and climatic changes, the second anomaly might have been influenced by Deccan volcanism which in turn predated KTB. Record of such anomalies preceding K-T boundary supports the view of multi-causal step-wise extinction of biota across KTB. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
