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DOI | 10.1130/B31866.1 |
U-Pb geochronology and geochemistry from the Kumaun Himalaya, NW India, reveal Paleoproterozoic arc magmatism related to formation of the Columbia supercontinent | |
Phukon, Purbajyoti1; Sen, Koushik1; Srivastava, Hari B.2; Singhal, Saurabh1; Sen, Aranya1 | |
2018-07-01 | |
发表期刊 | GEOLOGICAL SOCIETY OF AMERICA BULLETIN |
ISSN | 0016-7606 |
EISSN | 1943-2674 |
出版年 | 2018 |
卷号 | 130页码:1164-1176 |
文章类型 | Article |
语种 | 英语 |
国家 | India |
英文摘要 | Columbia was a Proterozoic supercontinent that formed similar to 2.0 b.y. ago by amalgamation of almost all the present-day continental blocks. One major controversy regarding the formation of this supercontinent is the position and tectonic setting of the north Indian continental margin during this amalgamation. One school of thought suggests that this margin remained passive throughout the continental accretion process, and another school contradicts that by suggesting subduction and an active continental arc setting. The Paleoproterozoic basement rocks of the Himalaya consist of granitic gneisses from the Lesser Himalayan Sequence that belonged to the north Indian continental margin during the formation of Columbia. In this work, we present bulk-rock geochemistry and U-Pb geochronology of zircon from augen gneisses of the Lesser Himalayan Munsiari Formation and granite gneisses of the Chiplakot Crystalline Belt of the Kumaun Himalaya, from Kali River Valley, India. Our objective was to evaluate the tectonic setting of these rocks to infer the nature of the Proterozoic north Indian continental margin. Bulk-rock geochemistry of four samples from the Munsiari augen gneiss and six samples from the granite gneisses from Chiplakot Crystalline Belt shows calc-alkaline and shoshonitic composition, respectively. Depletion in Nb, Sr, P, and Ti point toward a magmatic arc origin for both units. U-Pb chronology of zircon was carried out on two samples from the Munsiari augen gneiss and three samples from the Chiplakot Crystalline Belt. All of these samples yielded ages ranging from ca. 1970 Ma to ca. 1860 Ma, with crystallization ages in the Musiari augen gneiss varying from ca. 1970 to ca. 1950 Ma and ages in the Chiplakot Crystalline Belt at ca. 1920 Ma. Based on these results, it is inferred that both the Munsiari augen gneiss and the Chiplakot Crystalline Belt belong to the Inner Lesser Himalayan Sequence, and the magmatism took place within a span of similar to 100 m.y. related to active subduction along the Proterozoic north Indian continental margin. It is envisaged that the slightly older and highly fractionated calc-alkaline Munsiari augen gneiss reflects mixing of mantle and crustal melt along with assimilation and fractional crystallization. On the other hand, the Chiplakot Crystalline Belt is less fractionated and may have intruded during a later part of continental arc magmatism into a thinner crust, associated with crustal extension probably driven by slab break-off and/or slab rollback. Our study indicates that the north Indian continental margin was indeed an active subduction zone during the formation of Columbia. |
领域 | 地球科学 |
收录类别 | SCI-E |
WOS记录号 | WOS:000437009200008 |
WOS关键词 | MAIN CENTRAL THRUST ; CHIPLAKOT CRYSTALLINE BELT ; TECTONIC IMPLICATIONS ; NEPAL HIMALAYA ; MESOPROTEROZOIC SUPERCONTINENT ; METAMORPHIC CORE ; LESSER HIMALAYA ; SIKKIM HIMALAYA ; VOLCANIC-ROCKS ; TRACE-ELEMENT |
WOS类目 | Geosciences, Multidisciplinary |
WOS研究方向 | Geology |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/24685 |
专题 | 地球科学 |
作者单位 | 1.Wadia Inst Himalayan Geol, 33 GMS Rd, Dehra Dun 248001, Uttar Pradesh, India; 2.Banaras Hindu Univ, Inst Sci, Dept Geol, Varanasi 221005, Uttar Pradesh, India |
推荐引用方式 GB/T 7714 | Phukon, Purbajyoti,Sen, Koushik,Srivastava, Hari B.,et al. U-Pb geochronology and geochemistry from the Kumaun Himalaya, NW India, reveal Paleoproterozoic arc magmatism related to formation of the Columbia supercontinent[J]. GEOLOGICAL SOCIETY OF AMERICA BULLETIN,2018,130:1164-1176. |
APA | Phukon, Purbajyoti,Sen, Koushik,Srivastava, Hari B.,Singhal, Saurabh,&Sen, Aranya.(2018).U-Pb geochronology and geochemistry from the Kumaun Himalaya, NW India, reveal Paleoproterozoic arc magmatism related to formation of the Columbia supercontinent.GEOLOGICAL SOCIETY OF AMERICA BULLETIN,130,1164-1176. |
MLA | Phukon, Purbajyoti,et al."U-Pb geochronology and geochemistry from the Kumaun Himalaya, NW India, reveal Paleoproterozoic arc magmatism related to formation of the Columbia supercontinent".GEOLOGICAL SOCIETY OF AMERICA BULLETIN 130(2018):1164-1176. |
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