DOI: 10.1016/j.epsl.2020.116079
论文题名: Sediment provenance of pre- and post-collisional Cretaceous–Paleogene strata from the frontal Himalaya of northwest India
作者: Colleps C.L. ; McKenzie N.R. ; Horton B.K. ; Webb A.A.G. ; Ng Y.W. ; Singh B.P.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 534 语种: 英语
中文关键词: geochronology
; Himalaya
; India–Asia collision
; northwest India
; provenance
; zircon
英文关键词: Binary alloys
; Deposits
; Geochronology
; Hafnium
; Isotopes
; Lead alloys
; Silicate minerals
; Uranium alloys
; Zircon
; Himalayas
; Isotopic signatures
; northwest India
; Paleoproterozoic
; provenance
; Relative abundance
; Sediment provenance
; Sediment sources
; Zircon deposits
; age determination
; continental collision
; Cretaceous-Paleogene boundary
; geochronology
; Indian plate
; provenance
; zircon
; Himalayas
; India
; Lesser Himalayas
英文摘要: Whereas the timing for India–Asia collision remains debated, contrasting collisional models provide testable predictions in terms of sediment source contributions during the accumulation of Paleocene to middle Eocene deposits now exposed in the frontal Himalayan system. Within the Lesser Himalaya and frontal thrust system of northwest India, discontinuous exposures of the Cretaceous Singtali Formation and upper Paleocene–middle Eocene Subathu Formation yield a record of these early collisional stages. To test competing collisional models, we analyze the provenance of these deposits with new detrital zircon U-Pb and Hf isotopic data which can distinguish among Indian plate, Asian plate, Kohistan-Ladahk arc, and various Himalayan sources. Detrital zircon age distributions for the Singtali Formation are dominated by Paleoproterozoic zircons with a distinct Cretaceous age component, whereas age data from the Subathu Formation record (1) a marked increase in the relative abundance of Cambrian–Neoproterozoic grains, (2) a decrease in the proportion of Paleoproterozoic grains, and (3) distinct Permian and Late Cretaceous–Paleocene age components. All Cretaceous grains from the Singtali Formation yielded crustal Hf isotopic signatures, indicating a distinctive pre-collisional source of Cretaceous grains of Indian affinity. Zircon Hf isotopic signatures from <320 Ma grains in the Subathu Formation show a significant lower to middle Eocene increase in source diversity, including juvenile grains most likely originating from the Asian plate and Kohistan-Ladakh arc. This requires inception of India-Asia collision by ∼44–50 Ma—the depositional age of the uppermost Subathu Formation. This major provenance shift is similar to that observed for pre- and post-collisional Tethyan Himalayan strata in the north, which is suggestive of a single contiguous basin linking the Lesser Himalaya by ∼44–50 Ma and contests the notion that the Lesser and Tethyan Himalaya were separated by a “Greater India Basin” during the Eocene. When coupled with the well documented Paleocene–early Eocene provenance record of the Tethyan Himalaya, these new data provide support for a collisional model in which Asian detritus reached the northernmost edge of India by ∼59 Ma with terminal closure of both the Shyok and Indus-Yarlung suture zones by ∼54 Ma. © 2020 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164926
Appears in Collections: 气候变化与战略
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作者单位: Department of Earth Sciences, University of Hong Kong, Pokfulam, Hong Kong; Department of Geological Sciences, Jackson School of Geosciences, University of Texas at AustinTX 78712, United States; Institute for Geophysics and Department of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin, Austin, TX 78712, United States; Department of Geology, Panjab University, Chandigarh, 160014, India
Recommended Citation:
Colleps C.L.,McKenzie N.R.,Horton B.K.,et al. Sediment provenance of pre- and post-collisional Cretaceous–Paleogene strata from the frontal Himalaya of northwest India[J]. Earth and Planetary Science Letters,2020-01-01,534