40Ar/39Ar ages of alkaline and tholeiitic rocks from the northern Deccan Traps: implications for magmatic processes and the K–Pg boundary
MetadataShow full item record
The Deccan large igneous province in India was emplaced temporally close to the Cretaceous–Palaeogene (K–Pg) boundary and is formed by tholeiitic flood basalts and less abundant alkaline rocks. Definition of the origin of Deccanmagmatism and of its environmental impact relies on precise and accurate geochronological analyses.We present new40Ar/39Ar ages from the northern sector of the province. In this area, tholeiitic and alkaline rocks were contemporaneously emplaced at 66.60 ± 0.35 to 65.25 ± 0.29 Ma in the Phenai Mata area, whereas rocks from Rajpipla and Mount Pavagadh yielded ages ranging from 66.40 ± 2.80 to 64.90 ± 0.80 Ma. The indistinguishable ages for alkaline and tholeiitic magmatism suggest that distinct mantle sources were synchronously active. The new ages are compared with previous ages, which were carefully screened and filtered and then recalculated to be comparable. The entire dataset of geochronological data does not support a time-related migration of the magmatismrelated to the northward Indian platemovement relative to the Reunion mantle plume. The main phase of magmatism, including the newly dated rocks from the northern Deccan, occurred at the K–Pg boundary. This suggests a causal link between the emplacement of the province and the K–Pg mass extinction.
Showing items related by title, author, creator and subject.
Mesoproterozoic rifting and Pan-African continental collision in SE India: evidence from the Khariar alkaline complexUpadhyay, D.; Raith, M.; Mezger, K.; Bhattacharya, A.; Kinny, Peter (2006)The suture zone between the Bhandara craton and the granulite-facies rocks of the Eastern Ghats Province in SE India contains a number of deformed alkaline and tholeiitic intrusives. The Khariar alkaline complex is one ...
Petrology, geochronology and geochemistry of ca. 780 Ma A-type granites in South China: Petrogenesis and implications for crustal growth during the breakup of the supercontinent RodiniaWang, Q.; Wyman, D.; Li, Zheng-Xiang; Bao, Z.; Zhao, Z.; Wang, Y.; Jian, P.; Yang, Y.; Chen, L. (2010)There are widespread Neoproterozoic (830–740 Ma) calc-alkaline intrusive rocks in the South China Block, which has been considered a part of the Precambrian supercontinent Rodinia. The tectonic setting of these rocks, ...
Identification and isotopic studies of early Cambrian magmatism (El Carancho Igneous Complex) at the boundary between Pampia terrane and the Río de la Plata craton, La Pampa province, ArgentinaChernicoff, C.; Zappettini, E.; Santos, J.; Godeas, M.; Belousova, E.; McNaughton, Neal (2012)We have identified late Early Cambrian metaigneous rocks very poorly exposed at the Estancia El Carancho, in central La Pampa province, Argentina. They comprise calc–alkaline metadiorite and metagranite, and tholeiitic ...