Late Paleozoic tectonic evolution of Ganzi-Litang Ocean in Sanjiang region, Southwest China: Constraints from U-Pb geochronology of cumulate gabbro in Litang ophiolitic mélange belt

YU Guangming; MAO Shidong; ZHOU Zhenju; XIE Gen; HUANG Haoqing

doi:10.12097/gbc.2022.01.023

2024 Vol. 43, No. 1

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YU Guangming, MAO Shidong, ZHOU Zhenju, XIE Gen, HUANG Haoqing. 2024. Late Paleozoic tectonic evolution of Ganzi-Litang Ocean in Sanjiang region, Southwest China: Constraints from U-Pb geochronology of cumulate gabbro in Litang ophiolitic mélange belt. Geological Bulletin of China, 43(1): 61-75. doi: 10.12097/gbc.2022.01.023

Citation:

YU Guangming, MAO Shidong, ZHOU Zhenju, XIE Gen, HUANG Haoqing. 2024. Late Paleozoic tectonic evolution of Ganzi-Litang Ocean in Sanjiang region, Southwest China: Constraints from U-Pb geochronology of cumulate gabbro in Litang ophiolitic mélange belt. Geological Bulletin of China, 43(1): 61-75. doi: 10.12097/gbc.2022.01.023

Late Paleozoic tectonic evolution of Ganzi-Litang Ocean in Sanjiang region, Southwest China: Constraints from U-Pb geochronology of cumulate gabbro in Litang ophiolitic mélange belt

1.
Natural Resources Comprehensive Survey Command Center, China Geological Survey, Beijing 100055, China
2.
State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing 100083, China
3.
Institute of Geomechanics, Chinese Academy of Geological Science, Beijing 100081, China
4.
Center for Geophysical Survey Center, China Geological Survey, Langfang 065000, Hebei, China

Received Date: 21 January 2022

Revised Date: 24 August 2022

Publish Date: 15 January 2024

Abstract

Abstract

Located in the northwest of Gaocheng Town, Litang County, the Caganglongwa rock Formation is a set of ophiolitic mélange with basalt as the matrix. LA-ICP-MS zircon U-Pb dating of the cumulate gabbro in the ophiolitic mélange shows an age distribution range from 274 Ma to 349 Ma, indicating two age groups. The first group of baddeleyite ²⁰⁶Pb/²³⁸U has a weighted average age of 346 ± 17 Ma, which represents the age of early magmatism of cumulate gabbro; the second group of baddeleyite ²⁰⁶Pb/²³⁸U has a weighted average age of 286.2 ± 5.1 Ma, which represents the crystallization age for late magmatism of cumulate gabbro. The ultrabasic and basic rocks in the Caganglongwa rock Formation display combined characteristics of N-MORB and E-MORB, indicating that these rocks may be formed in the mid-ocean ridge environment, and the magma material comes from a mixed source region formed by depleted upper mantle source region represented by N-MORB and metasomatically contaminated by the mantle plume. The research finds that the Ganzi-Litang Ocean may begin to stretch as early as the Middle Devonian due to the regional mantle plume activity, resulting in the split of the Zhongza block from the western margin of the Yangtze block and the Formation of an ocean basin in the Early Carboniferous. By the Mid-Late Triassic, the Ganzi-Litang oceanic crust was subducted westward and closed at the end of the Late Triassic, and the region entered the arc-continent collision orogeny stage.
- baddeleyite U-Pb age /
- cumulate gabbro /
- Caganglongwa rock Formation /
- Ganzi-Litang ophiolitic mélange belt

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References

[1]	Dunning G R, Peterson R B. 1988. U/Pb ages of ophiolites and arc-related cratons of the Norwegian Caledonides: Implications for the development of impetus[J]. Contribution to Mineralogy and Petrology, 98: 13−23. doi: 10.1007/BF00371904 CrossRef Google Scholar
[2]	Sturt B A, Thon A, Furnes H. 1979. The karmoy ophiolite, southwest Norway[J]. Geology, 7: 316−320. Google Scholar
[3]	Sun S S, MacDonough W F. 1989. Chemical and isotopic systematics of oceanic basalts: implication for mantle composition and processes[J]. Geological Society London, Special Publication, 42: 313−345. doi: 10.1144/GSL.SP.1989.042.01.19 CrossRef Google Scholar
[4]	Wang B Q, Zhou M F, Chen W T, et al. 2013. Petrogenesis and tectonic implications of the Triassic volcanic rocks in the northern Yidun Terrane, Eastern Tibet[J]. Lithos, 175/176: 285−301. doi: 10.1016/j.lithos.2013.05.013 CrossRef Google Scholar
[5]	Winchester J A, Floyd P A. 1977. Geochemical discrimination of different magma series their differentiation products using immobile elements[J]. Chem. Geol., 20: 325−345. doi: 10.1016/0009-2541(77)90057-2 CrossRef Google Scholar
[6]	Wood D A. 1980. The application of a Th-Hf-Ta diagram to problems of tectonomagmatic classification and to establishing the nature of crustal contamination of basaltic lavas of the British Tertiary volcanic province[J]. Earth and Plaetary Science Letters, 50: 11−30. doi: 10.1016/0012-821X(80)90116-8 CrossRef Google Scholar
[7]	范蔚茗, 王岳军, 彭头平, 等. 2004. 桂西晚古生代玄武岩Ar-Ar和U-Pb年代学及其对峨眉山玄武岩省喷发时代的约束[J]. 科学通报, 49(18): 1892−1900. Google Scholar
[8]	侯增谦, 卢记仁, 李红阳, 等. 1996. 中国西南特提斯构造演化——幔柱构造控制[J]. 地球学报, 17(4): 439−453. Google Scholar
[9]	侯增谦, 曲晓明, 周继荣, 等. 2001. 三江地区义敦岛弧碰撞造山过程: 花岗岩记录[J]. 地质学报, 75(4): 484−497. Google Scholar
[10]	黄豪擎. 2019. 川理塘地区蛇绿混杂岩地质特征及其构造演化[D]. 中国地质大学(北京)硕士学位论文. Google Scholar
[11]	简平, 刘敦一, 张旗, 等. 2003. 蛇绿岩及蛇绿岩中浅色岩SHRIMP U-Pb测年[J]. 地学前缘, 10(4): 439−456. Google Scholar
[12]	简平, 汪啸风, 何龙清, 等. 1998. 中国西南哀牢山蛇绿岩同位素地质年代学及大地构造意义[J]. 华南地质与矿产, (1): 1−11. Google Scholar
[13]	李春昱. 1980. 中国板块构造的轮廓[J]. 中国地质科学院院报, 2(1): 11−22. Google Scholar
[14]	李文昌, 潘桂棠, 侯增谦, 等. 2010. 西南三江多岛弧盆-碰撞造山成矿理论与勘查技术[M]. 北京: 地质出版社: 38−40. Google Scholar
[15]	李艳广, 汪双双, 刘民武, 等. 2015. 斜锆石LA-ICP-MS U-Pb定年方法及应用[J]. 地质学报, 89(12): 2400−2418. Google Scholar
[16]	林金录. 1987. 中国古地磁数据表(Ⅰ)[J]. 地质科学, (2): 183−187. Google Scholar
[17]	刘宝田, 江耀明, 曲景川. 1983. 四川理塘—甘孜一带古洋壳的发现及其对板块构造的意义[C]//青藏高原地质文集. 北京: 地质出版社, 119−127. Google Scholar
[18]	莫宣学, 路凤香, 沈上越, 等. 1993. 三江特提斯火山作用与成矿[M]. 北京: 地质出版社: 19−32. Google Scholar
[19]	潘桂棠, 陈智梁, 李兴振, 等. 1997. 东特提斯构造的形成与演化[M]. 北京: 地质出版社: 41−43. Google Scholar
[20]	曲晓明, 侯增谦. 2002. 从潘拥枕状玄武岩的⁴⁰Ar-³⁹Ar年龄论金沙江缝合带和甘孜—理塘缝合带的演化关系[J]. 地质论评, 48(增刊): 115−121. Google Scholar
[21]	宋谢炎, 王玉兰, 曹志敏, 等. 1998. 峨眉山玄武岩、峨眉地裂运动与幔热柱[J]. 地质地球化学, 1: 47−52. Google Scholar
[22]	王保弟, 王立全, 潘桂棠, 等. 2013. 昌宁-孟连结合带南汀河早古生代辉长岩锆石年代学及地质意义[J]. 科学通报, 58(4): 344−354. Google Scholar
[23]	王连城, 张旗. 1985. 四川理塘蛇绿混杂岩——一个以火山岩为基质的蛇绿混杂带[J]. 岩石学报, 1(2): 17−27. Google Scholar
[24]	肖龙, 徐义刚, 何斌. 2005. 试论地幔柱构造与川滇西部古特提斯的演化[J]. 地质科技情报, 24(4): 1−6. Google Scholar
[25]	谢力, 杨文强, 刘桂春, 等. 2012. 云南香格里拉上三叠统沉积混杂岩中的晚古生代和中三叠世放射虫及其地质意义[J]. 微体古生物学报, 3: 253−269. Google Scholar
[26]	闫全人, 王宗起, 刘树文, 等. 2005. 西南三江特提斯洋扩张与晚古生代东冈瓦纳裂解: 来自甘孜蛇绿岩辉长岩的SHRIMP年代学证据[J]. 科学通报, 50(2): 158−166. Google Scholar
[27]	严松涛, 谭昌海, 秦蒙, 等. 2021. 甘孜——理塘蛇绿混杂岩带中段理塘地区混杂岩物质组成及其地质演化[J]. 中国地质, 48(6): 1825−1845. Google Scholar
[28]	严松涛, 吴青松, 朱利东, 等. 2023. 甘孜-理塘蛇绿混杂岩带晚三叠世洋岛型岩石组合识别及其对甘孜-理塘洋盆构造演化的制约[J]. 地质通报, 42(10): 1684−1695. doi: 10.12097/j.issn.1671-2552.2023.10.006 CrossRef Google Scholar
[29]	杨文强, 冯庆来, 刘桂春. 2010. 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, 84(1): 78−89. Google Scholar
[30]	尹福光, 罗亮, 任飞. 2022. 再造西南"三江"造山带洋陆转换过程中的构造与古地理[J]. 地质通报, 41(11): 1899−1914. doi: 10.12097/j.issn.1671-2552.2022.11.001 CrossRef Google Scholar
[31]	张世红, 朱鸿, 孟小红. 2001. 扬子地块泥盆纪石炭纪古地磁新结果及其古地理意义[J]. 地质学报, 75(3): 303−313. Google Scholar
[32]	张世涛, 冯庆来, 王义昭. 2000. 甘孜-理塘构造带泥盆系的深水沉积[J]. 地质科技情报, 19(3): 17−20. Google Scholar
[33]	张之孟, 金蒙. 1979. 川西南乡城-得荣地区的两种混杂岩及其构造意义[J]. 地质科学, (3): 205−213. Google Scholar
[34]	钟大赉. 1998. 滇川西部古特提斯造山带[M]. 北京: 科学出版社: 1−231. Google Scholar
[35]	周晨. 2018. 理塘擦岗隆洼岩组含放射虫硅质岩地球化学特征与形成环境[D]. 中国地质大学(北京)硕士学位论文. Google Scholar