DOI: 10.1016/j.epsl.2020.116616
论文题名: Widespread silicic and alkaline magmatism synchronous with the Deccan Traps flood basalts, India
作者: Basu A.R. ; Chakrabarty P. ; Szymanowski D. ; Ibañez-Mejia M. ; Schoene B. ; Ghosh N. ; Bastian Georg R.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 552 语种: 英语
中文关键词: Deccan Large Igneous Province
; Narmada–Tapti lineament
; Saurashtra Peninsula
; zircon geochronology
英文关键词: Geochronology
; Lead alloys
; Silicate minerals
; Zircon
; Continental break-up
; Continental crusts
; Mass extinction
; Organic-rich sediment
; Sedimentary strata
; Temporal relationships
; Thermal imprint
; Zircon U-Pb age
; Basalt
; alkaline rock
; Cretaceous-Paleogene boundary
; Deccan Traps
; flood basalt
; geochronology
; large igneous province
; lineament
; Maastrichtian
; magmatism
; paleoenvironment
; siliciclastic deposit
; synchrony
; uranium-lead dating
; volcanism
; zircon
; Deccan
; India
; Trachytes
英文摘要: Deccan Traps (DT) volcanism and the Chicxulub bolide impact have been suggested as potential triggers of the Cretaceous–Paleogene boundary (KPB) mass extinction. Recently published geochronology has established a timeline for the main basaltic sequence of the DT, showing that the majority of eruptions occurred within 700–800 kyr spanning the KPB. Silicic to alkaline magmatism linked to the DT, spatially associated with the Narmada lineament in central India, has been long known but not as well studied. Previous geochronology of some of the felsic magmatic centers has yielded dates that span many millions of years, making their temporal relationship with DT volcanism uncertain. We present zircon U-Pb ages from the Alech, Barda, Girnar, Rajula and Phenai Mata silicic–alkaline complexes, in addition to a series of trachytes on the coastal plain near Mumbai. While the trachytes are ∼64 Ma and mark the continental breakup of India ∼1.5 Myr after the main phase of DT eruptions, the silicic-alkaline complexes were all emplaced coevally with the main phase of DT volcanism ca. 66.2-65.7 Ma. Initial εHf in zircons (+10 to -20), whole-rock 87Sr/86Sr (0.702439-0.760932) and εNd (+1.11 to -35.7) for all five intrusive complexes suggest a hybrid origin involving juvenile sources as well as significant assimilation of older continental crust. Recognition that the silicic-alkaline complexes are coeval with basaltic magmatism and associated with a significant thermal imprint on the crust in and near the Narmada rift sedimentary strata supports the hypothesis that outgassing of organic-rich sediments may have contributed to the end-Maastrichtian warming and biologic crisis. © 2020 Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164857
Appears in Collections: 气候变化与战略
There are no files associated with this item.
作者单位: Department of Earth and Environmental Sciences, University of Texas at Arlington, Arlington, TX 76019, United States; Department of Geosciences, Princeton University, Guyot Hall, Princeton, NJ 08544, United States; Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY 14627, United States; Department of Earth and Environment, Boston University, Boston, MA 02215, United States; Trent University Water Quality Center, Peterborough, ON K9L 0G2, Canada
Recommended Citation:
Basu A.R.,Chakrabarty P.,Szymanowski D.,et al. Widespread silicic and alkaline magmatism synchronous with the Deccan Traps flood basalts, India[J]. Earth and Planetary Science Letters,2020-01-01,552