OCEANIC ISLAND BASALTS IN GARZE-LITANG JUNCTION ZONE, WESTERN SICHUAN PROVINCE: Geochemistry, Geochronology and Geological Implication

LUO Shao-qiang; TANG Hua; XIAO jin; LIU Da-ming; DAI Lun

doi:10.13686/j.cnki.dzyzy.2021.06.003

2021 Vol. 30, No. 6

Article Contents

Article navigation > Geology and Resources > 2021 > 30(6): 656-665

Next Article Previous Article

LUO Shao-qiang, TANG Hua, XIAO jin, LIU Da-ming, DAI Lun. OCEANIC ISLAND BASALTS IN GARZE-LITANG JUNCTION ZONE, WESTERN SICHUAN PROVINCE: Geochemistry, Geochronology and Geological Implication[J]. Geology and Resources, 2021, 30(6): 656-665. doi: 10.13686/j.cnki.dzyzy.2021.06.003

Citation:

LUO Shao-qiang, TANG Hua, XIAO jin, LIU Da-ming, DAI Lun. OCEANIC ISLAND BASALTS IN GARZE-LITANG JUNCTION ZONE, WESTERN SICHUAN PROVINCE: Geochemistry, Geochronology and Geological Implication[J]. Geology and Resources, 2021, 30(6): 656-665. doi: 10.13686/j.cnki.dzyzy.2021.06.003

OCEANIC ISLAND BASALTS IN GARZE-LITANG JUNCTION ZONE, WESTERN SICHUAN PROVINCE: Geochemistry, Geochronology and Geological Implication

Northwest Sichuan Geological Team, Sichuan Bureau of Geology and Mineral Resources, Mianyang 621000, Sichuan Province, China

Received Date: 14 July 2020

Revised Date: 10 October 2020

Publish Date: 28 December 2021

Abstract

Abstract

A large number of oceanic island-seamount rock assemblages are developed in Ganze-Litang junction zone-an important part of Sanjiang Tethyan Orogen and Songpan-Ganze Orogen. The existence of oceanic island basalts (OIB) indicates that mature oceanic crust has developed in the ocean basin. The oceanic island-seamount rock assemblages in Muli area are composed of basic volcanic rocks and carbonate rocks. The geochemical analysis of basic volcanic rocks shows the SiO₂ content of 40.17%-49.19%, TiO₂ 1.77%-4.86%, Al₂O₃ 9.67%-15.39%, MgO 3.85%-17.75% and total alkali (K₂O+Na₂O) 0.87%-6.33%, respectively, belonging to alkali basalt series. The basalts are characterized by high ∑REE (106.21×10^-6-378.83×10^-6), (La/Yb)_N of 9.23-39.41, LREEs enrichment, without Eu and Ce anomalies, right-dipping distribution patterns, enriched LILEs (Rb, Ba, Th and K), and depleted HFSEs (Nb and Zr). The characteristics of REEs and trace elements are similar to those of standard OIBs, with the provenance of garnet peridotite from asthenosphere mantle, some undergoing magmatic crystallization differentiation and forming in oceanic island platform environment. The zircon U-Pb dating result of basalts (218.96-221.71 Ma) reveals that the OIBs were formed in middle Late Triassic.
- geochemistry /
- geochronology /
- oceanic island basalt (OIB) /
- Garze-Litang junction zone /
- Late Triassic /
- Sichuan Province

FullText(HTML)

References

[1]	许志琴, 侯立玮, 王宗秀, 等. 中国松潘-甘孜造山带的造山过程[M]. 北京: 地质出版社, 1992: 170-172. Google Scholar Xu Z Q, Hou L W, Wang Z X, et al. Orogenic processes of the Songpan-Ganze orogenic belt of China[M]. Beijing: Geological Publishing House, 1992: 170-172. (in Chinese) Google Scholar
[2]	邹光富, 侯立玮, 尹显科. 甘孜-理塘蛇绿混杂岩带特征及其构造意义[J]. 四川地质学报, 1994, 14(1): 17-24. Google Scholar Zou G F, Hou L W, Yin X K. Characteristics of Garze-Litang ophiolite melange zone and its tectonic implication[J]. Acta Geologica Sichuan, 1994, 14(1): 17-24. Google Scholar
[3]	蔡雄飞, 蔡海磊, 刘德民. 造山带洋岛混杂岩系地层序列和研究意义[J]. 海洋地质动态, 2006, 22(4): 9-11. doi: 10.3969/j.issn.1009-2722.2006.04.003 CrossRef Google Scholar Cai X F, Cai H L, Liu D M. Stratigraphic sequences of mixtite series in oceanic islands of orogenic belts and the significance of study[J]. Marine Geology Letters, 2006, 22(4): 9-11. doi: 10.3969/j.issn.1009-2722.2006.04.003 CrossRef Google Scholar
[4]	严松涛, 段阳海, 谭昌海, 等. 甘孜-理塘蛇绿混杂岩带中三叠世洋岛型岩石组合的识别及其构造意义——来自岩石学、地球化学和年代学证据[J]. 地球学报, 2019, 40(6): 816-826. Google Scholar Yan S T, Duan Y H, Tan C H, et al. Identification of the Middle Triassic Ocean Island rock association in the Garze-Litang ophiolite mélange zone and its tectonic significance: Constraints from petrology, geochemistry and geochronology[J]. Acta Geoscientica Sinica, 2019, 40(6): 816-826. Google Scholar
[5]	王立全, 潘桂堂, 丁俊, 等. 1: 150万青藏高原及邻区地质图及说明书[M]. 北京: 地质出版社, 2013: 114. Google Scholar Wang L Q, Pan G T, Ding J, et al. Geological maps and specifications of the Tibetan plateau and its adjacent areas[M]. Beijing: Geological Publishing House, 2013: 114. (in Chinese) Google Scholar
[6]	曾云, 贺金良, 王秀京, 等. 四川省成矿区带划分及区域成矿规律[M]. 北京: 科学出版社, 2015: 9-10. Google Scholar Zeng Y, He J L, Wang X J, et al. Zoning of metallogenic belt and regional metallogenic regularity in Sichuan Province[M]. Beijing: Science Press, 2015: 9-10. Google Scholar
[7]	侯可军, 李延河, 田有荣. LA-MC-ICP-MS锆石微区原位U-Pb定年技术[J]. 矿床地质, 2009, 28(4): 481-492. doi: 10.3969/j.issn.0258-7106.2009.04.010 CrossRef Google Scholar Hou K J, Li Y H, Tian Y R. In situ U-Pb zircon dating using laser ablation-multi ion counting-ICP-MS[J]. Mineral Deposits, 2009, 28(4): 481-492. doi: 10.3969/j.issn.0258-7106.2009.04.010 CrossRef Google Scholar
[8]	马涛, 张健, 王晓青, 等. 西藏萨嘎二叠纪OIB型火山岩岩石地球化学特征及成因分析[J]. 西北地质, 2017, 50(3): 22-35. doi: 10.3969/j.issn.1009-6248.2017.03.004 CrossRef Google Scholar Ma T, Zhang J, Wang X Q, et al. Geochemical characteristics and genesis of Permian OIB-type volcanic rocks in Saga region, Tibet[J]. Northwestern Geology, 2017, 50(3): 22-35. doi: 10.3969/j.issn.1009-6248.2017.03.004 CrossRef Google Scholar
[9]	Wilkinson J F G. The genesis of mid-ocean ridge basalt[J]. Earth-Science Reviews, 1982, 18(1): 1-57. doi: 10.1016/0012-8252(82)90002-2 CrossRef Google Scholar
[10]	邓晋福. 岩石相平衡与岩石成因[M]. 武汉: 武汉地质学院出版社, 1987: 24-31. Google Scholar Deng J F. Lithofacies equilibrium and petrogenesis[M]. Wuhan: China University of Geoscience Press, 1987: 24-31. (in Chinese) Google Scholar
[11]	Winchester J A, Floyd P A. Geochemical discrimination of different magma series and their differentiation products using immobile elements[J]. Chemical Geology, 1977, 20: 325-343. doi: 10.1016/0009-2541(77)90057-2 CrossRef Google Scholar
[12]	李运冬, 刘小玉. 青海热水地区晚三叠世火山岩地球化学特征及构造环境[J]. 西北地质, 2014, 47(3): 14-25. doi: 10.3969/j.issn.1009-6248.2014.03.005 CrossRef Google Scholar Li Y D, Liu X Y. Geochemistry and tectonic setting of late Triassic volcanic rocks in Reshui area, Qinghai[J]. Northwestern Geology, 2014, 47(3): 14-25. doi: 10.3969/j.issn.1009-6248.2014.03.005 CrossRef Google Scholar
[13]	Weaver B L. The origin of ocean island basalt end-member compositions: Trace element and isotopic constraints[J]. Earth and Planetary Science Letters, 1991, 104(2/4): 381-397. Google Scholar
[14]	Sun S S, McDonough W F. Chemical and isotopic systematics of oceanic basalts: Implications for mantle composition and processes[C]//Saunders A D, Norry M J. Magmatism in the Ocean Basins. Geological Society, London, Special Publications, 1989, 42(1): 313-345. Google Scholar
[15]	徐义刚. 地幔柱构造、大火成岩省及其地质效应[J]. 地学前缘, 2002, 9(4): 341-353. doi: 10.3321/j.issn:1005-2321.2002.04.014 CrossRef Google Scholar Xu Y G. Mantle plumes, large igneous provinces and their geologic consequences[J]. Earth Science Frontiers, 2002, 9(4): 341-353. doi: 10.3321/j.issn:1005-2321.2002.04.014 CrossRef Google Scholar
[16]	Pearce J A, Cann J R. Tectonic setting of basic volcanic rocks determined using trace element analyses[J]. Earth and Planetary Science Letters, 1973, 19(2): 290-300. doi: 10.1016/0012-821X(73)90129-5 CrossRef Google Scholar
[17]	Le Roex A P, Dick H J B, Erlank A J, et al. Geochemistry, mineralogy and petrogenesis of lavas erupted along the Southwest Indian Ridge between the Bouvet triple junction and 11 degrees east[J]. Journal of Petrology, 1983, 24(3): 267-318. doi: 10.1093/petrology/24.3.267 CrossRef Google Scholar
[18]	Weaver B L. Trace element evidence for the origin of ocean-island basalts[J]. Geology, 1991, 19(2): 123-126. doi: 10.1130/0091-7613(1991)019<0123:TEEFTO>2.3.CO;2 CrossRef Google Scholar
[19]	Viccaro M, Cristofolini R. Nature of mantle heterogeneity and its role in the short-term geochemical and volcanological evolution of Mt. Etna (Italy)[J]. Lithos, 2008, 105(3/4): 272-288. Google Scholar
[20]	Helo C, Hegner E, Kröner A, et al. Geochemical signature of Paleozoic accretionary complexes of the Central Asian Orogenic Belt in South Mongolia: Constraints on arc environments and crustal growth[J]. Chemical Geology, 2006, 227(3/4): 236-257. Google Scholar
[21]	韩兆诣. 甘孜-理塘结合带南段玄武岩特征及构造意义[D]. 绵阳: 西南科技大学, 2015. Google Scholar Han Z Y. Basalt characteristics and tectonic significance in the Southern of Garze-Litang Suture Zone[D]. Minyang: Southwest University of Science and Technology, 2015. Google Scholar
[22]	鄢圣武, 白宪洲, 秦宇龙, 等. 四川昭觉-美姑地区峨眉山玄武岩古火山机构的发现及其喷发旋回的确定[J]. 中国地质, 2021, 48(2): 536-548. Google Scholar Yan S W, Bai X Z, Qin Y L, et al. Discovery of paleo-volcanic edifice and determination of its eruptive circles of Emeishan basalt in Zhaojue-Meigu area, Sichuan Province[J]. Geology in China, 2021, 48(2): 536-548. Google Scholar
[23]	谢纪海, 胡正祥, 毛新武, 等. 鄂北大洪山晋宁期MORB-like玄武岩的识别与洋内俯冲作用[J]. 中国地质, 2019, 46(6): 1496-1511. Google Scholar Xie J H, Hu Z X, Mao X W, et al. The discrimination of Jinningian MORB-like basalt and intra-oceanic subduction in the Dahongshan area, northern Hubei[J]. Geology in China, 2019, 46(6): 1496-1511. Google Scholar
[24]	Pearce J A, Norry M J. Petrogenetic implications of Ti, Zr, Y, and Nb variations in volcanic rocks[J]. Contributions to Mineralogy and Petrology, 1979, 69(1): 33-47. doi: 10.1007/BF00375192 CrossRef Google Scholar
[25]	Mullen E D. MnO/TiO₂/P₂O₅: A minor element discriminant for basaltic rocks of oceanic environments and its implications for petrogenesis[J]. Earth and Planetary Science Letters, 1983, 62(1): 53-62. doi: 10.1016/0012-821X(83)90070-5 CrossRef Google Scholar
[26]	Vermeesch P. Tectonic discrimination diagrams revisited[J]. Geochemistry, Geophysics, Geosystems, 2006, 7(6): Q06017. Google Scholar
[27]	潘桂棠, 陈智梁, 李兴振, 等. 东特提斯地质构造形成演化[M]. 北京: 地质出版社, 1997: 69-107. Google Scholar Pan G T, Chen Z L, Li X Z, et al. Geological-Tectonic evolution in the Eastern Tethys[M]. Beijing: Geological Publishing House, 1997: 69-107. (in Chinese) Google Scholar
[28]	张世涛, 冯庆来, 王义昭. 甘孜-理塘构造带泥盆系的深水沉积[J]. 地质科技情报, 2000, 19(3): 17-20. doi: 10.3969/j.issn.1000-7849.2000.03.004 CrossRef Google Scholar Zhang S T, Feng Q L, Wang Y Z. Devonian deep-water sediments in Garze-Litang tectonic belt[J]. Geological Science and Technology Information, 2000, 19(3): 17-20. doi: 10.3969/j.issn.1000-7849.2000.03.004 CrossRef Google Scholar
[29]	杨文强, 冯庆来, 刘桂春. 滇西北甘孜-理塘构造带放射虫地层、硅质岩地球化学及其构造古地理意义[J]. 地质学报, 2010, 84(1): 78-89. doi: 10.3969/j.issn.1004-9665.2010.01.011 CrossRef Google Scholar Yang W Q, Feng Q L, Liu G C. Radiolarian fauna and geochemical characters of the cherts from Garze-Litang tectonic belt and its tectono-paleogeographic significance[J]. Acta Geologica Sinica, 2010, 84(1): 78-89. doi: 10.3969/j.issn.1004-9665.2010.01.011 CrossRef Google Scholar