The Himalayan collision zone carbonatites in western Sichuan, SW China:;Petrogenesis, mantle source and tectonic implication

doi:10.1016/j.epsl.2006.01.052

	The Himalayan collision zone carbonatites in western Sichuan, SW China:;Petrogenesis, mantle source and tectonic implication
	Hou, ZQ 5; Tian, SH ; Yuan, ZX ; Xie, YL ; Yin, SP ; Yi, LS ; Fei, HC ; Yang, ZM
刊名	EARTH AND PLANETARY SCIENCE LETTERS
	2006
卷号	244 期号:1-2 页码:234-250
关键词	carbonatite petrogenesis mantle source collision zone east Tibet
ISSN号	0012-821X
DOI	10.1016/j.epsl.2006.01.052
英文摘要	Major and trace element compositions, and Sr-Nd-Pb and O-C isotope data for Cenozoic carbonatites (WSC) in western Sichuan, east Tibet, China are presented in this paper. The WSC occur in the eastern Indo-Asian collision zone (EIACZ), and occur as sills or dykes in the contemporaneous syenitic intrusions, which form a 270-km long, NS-trending belt of carbonatite-alkalic complexes, controlled by strike-slip faults that accommodated and adjusted to the collision strain. These carbonatite-alkalic complexes with Cenozoic potassic felsic rocks and calc-alkaline (shoshonitic) lamprophyres form a semi-continuous potassic igneous province with magmatism peaking at similar to 35Ma in the EIACZ.;The WSC are characterized by low SiO2 (< 10.22 %), FeO (< 1.20 %) and MgO (< 0.73 %), and a wide range of CaO content (40.7 similar to 55.4 %) that distinguish them from primary magnesiocarbonatites. Overlapping emplacement ages and Sr-Nd isotopic compositions and similar mantle-normalized trace element patterns to spatially associated syenites suggest an origin for the carbonatites by liquid immiscibility.;The WSC are extremely enriched in LILE (Sr, Ba) and light REE, but relatively depleted in high-field strength elements (Nb, Ta, P, Zr, Hf, Ti), suggesting a metasomatized mantle source. Their delta O-18(V-SMOW) (6.4 similar to 10.5 parts per thousand) and delta C-13(V-PDB) (-3.9 to -8.5 parts per thousand) values are similar to those of primary, mantle-derived carbonatites, also suggesting a mantle genesis. However, they have extremely low aNd((t)) of -3.2 to -18.7 and relative high (Sr-87/Sr-86)(i) of 0.706020 similar to 0.707923, as well as a wide range of Pb-207/Pb-204 (15.362 similar to 15.679) and Pb-208/Pb-204 ratios (38.083 similar to 39.202), which distinguish them from most carbonatites around the world. Their Sr-Nd, Sr-Pb and Nd-Pb isotopic signatures indicate that some carbonatites underwent Sr-Nd-Pb contamination by crustal materials, but the least-contaminated carbonatites were derived from a transitional source between EMI and EMII components. The T-DM and modeling on Sr-Nd isotopic compositions indicate that the formation of this source probably was related to recycling of oceanic crust and pelagic/terrigenous sediments with various mass ratios. Partial melting of the mantle source was most likely triggered by a Cenozoic asthenospheric mantle diapir related to Indian-Asian continent collision at 65-45Ma. Rising and emplacement of carbonatitic magmas with coeval potassium-rich magmas took place in the tectonic regime of the transition from transpression to transtension at Eocene/Oligocene boundary in the EIACZ. (c) 2006 Elsevier B.V. All rights reserved.
学科主题	构造地质学
WOS关键词	SR ISOTOPE SYSTEMATICS ; EMEISHAN FLOOD BASALTS ; LIQU##ID#IMMISCIBILITY ; GEOCHEMICAL CONSTRAINTS ; TONGLING AREA ; ND ; PB ; ORIGIN ; COMPLEX ; OXYGEN
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000236991300016
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/38276]
专题	中国地质科学院
作者单位	1.Chinese Acad Geol Sci, Inst Geol, Beijing 100037, Peoples R China. 2.Minist Land & Resources, Key Lab Isotope Geol, Beijing 100037, Peoples R China. 3.Chinese Acad Geol Sci, Inst Mineral Resource, Beijing 100037, Peoples R China. 4.Beijing Univ Sci & Technol, Sch Civil & Environm Engn, Beijing 100083, Peoples R China. 5.中国地质科学院地质研究所
推荐引用方式 GB/T 7714	Hou, ZQ,Tian, SH,Yuan, ZX,et al. The Himalayan collision zone carbonatites in western Sichuan, SW China:;Petrogenesis, mantle source and tectonic implication[J]. EARTH AND PLANETARY SCIENCE LETTERS,2006,244(1-2):234-250.
APA	Hou, ZQ.,Tian, SH.,Yuan, ZX.,Xie, YL.,Yin, SP.,...&Yang, ZM.(2006).The Himalayan collision zone carbonatites in western Sichuan, SW China:;Petrogenesis, mantle source and tectonic implication.EARTH AND PLANETARY SCIENCE LETTERS,244(1-2),234-250.
MLA	Hou, ZQ,et al."The Himalayan collision zone carbonatites in western Sichuan, SW China:;Petrogenesis, mantle source and tectonic implication".EARTH AND PLANETARY SCIENCE LETTERS 244.1-2(2006):234-250.