Research / 2019 / Article / Fig 5

Research Article

Clay Mineral and Geochemical Proxies for Intense Climate Change in the Permian Gondwana Rock Record from Eastern India

Figure 5

(a) Stratigraphic variation of PAAS-normalized [37] major oxide composition of the mudstone from the Talchir and Barakar Formations. Note the strong enrichment of Na2O and depletion of Al2O3 in the Talchir mudstones and slight enrichment of Al2O3 coupled with depletion of mobile elements in the Barakar mudstones. (b) Plot in the A-CN-K diagram [18] for the mudstones of the Talchir and Barakar Formations. Note that the Talchir mudstones show a linear trend parallel to the A-CN side of the diagram and the Barakar mudstones plot parallel to the A-K side of the diagram. (c) Chondrite-normalized rare earth element (REE) plots for the Talchir and Barakar mudstones. Note the similarity in REE patterns for both the formations, high LREE/HREE ratio, flat HREE pattern, and pronounced negative Eu anomaly. PAAS and UCC are from Taylor and McLennan [37].