The discovery and limplications for the India-Eurasia Plate collision of the Nianbo Formation adakitic rocks from Yangyi basin in Middle Gangdise Belt

HU Lin; TANG Hua; XU Gang; LIU Daming; XIAO Jin

2020 Vol. 39, No. 10

Article Contents

Article navigation > Geological Bulletin of China > 2020 > 39(10): 1507-1517

Next Article Previous Article

HU Lin, TANG Hua, XU Gang, LIU Daming, XIAO Jin. The discovery and limplications for the India-Eurasia Plate collision of the Nianbo Formation adakitic rocks from Yangyi basin in Middle Gangdise Belt[J]. Geological Bulletin of China, 2020, 39(10): 1507-1517.

Citation:

HU Lin, TANG Hua, XU Gang, LIU Daming, XIAO Jin. The discovery and limplications for the India-Eurasia Plate collision of the Nianbo Formation adakitic rocks from Yangyi basin in Middle Gangdise Belt[J]. Geological Bulletin of China, 2020, 39(10): 1507-1517.

The discovery and limplications for the India-Eurasia Plate collision of the Nianbo Formation adakitic rocks from Yangyi basin in Middle Gangdise Belt

Northwest Sichuan Geological Party, Bureau of Geology and Mineral Resources Exploration and Development of Sichuan Province, Mianyang 621000, Sichuan, China

Received Date: 21 August 2019

Revised Date: 23 April 2020

Publish Date: 15 October 2020

Abstract

Abstract

The Eocene Nianbo Formation Adakitic volcanic rocks were discovered for the first time from the Yangyi basin in the Middle Gangdise Belt.This set of adakitic volcanic rocks consists of dacite, rhyolite, and volcanic lava.In order to determine their formation age, origin and geological tectonic significance, the authors conducted LA-ICP-MS zircon U-Pb geochronologic, petrographic and geochemical studies.The results show that the zircons used for dating are of magmatic origin, and the zircon ²⁰⁶Pb/²³⁸U dating yielded 55±0.8 Ma, which suggests that the volcano erupted in Eocene.Geochemical characteristics show that the volcanic rocks belong to a series of weakly peraluminous calc-alkaline rocks, and have rich Si(SiO₂ of 67.69%~71.93%), high Al(Al₂O₃ of 13.13% ~ 16.16%), low Mg(MgO of 0.52%~ 0.76%), higher Sr(Sr of 345×10^-6~875×10^-6), and lower Y(Y of 4.40×10^-6 ~11.30×10^-6)and Yb(Yb of 0.81×10^-6 ~1.49×10^-6).The total rare earth element values vary in the range of 116.86×10^-6~352×10^-6, exhibiting obvious fractionation between light and heavy REE((La/Yb)_N=23.31~43.66), with no obvious δEu anomaly(0.8~1.15).Enrichment of LILE(Rb, U and Th)and depletion of HFSE(Nb, P and Ti)are displayed in the primitive mantle normalized multi-element variation diagram, indicating geochemical characteristics of C-type adakitic volcanic rocks.Based on regional information, the authors hold that adakitic rocks of Nianbo Formation in Yangyi basin were formed by partial melting of thickened lower crust, indicating that some areas of the southern margin of Lhasa were thickened to about 50 km around 55±0.8 Ma.
- Nianbo Formation /
- C-type adakitic rocks /
- zircon U-Pb age /
- Middle Gangdise Belt /
- petrology

FullText(HTML)

References

[1]	Kay R W.Aleutian magnesian andesites; Melts from subdueted Pacific Ocean crus[J].Volcano Geotherm Res., 1978, 4:117-132. doi: 10.1016/0377-0273(78)90032-X CrossRef Google Scholar
[2]	Defant M J, Drurnmond M S.Derivation of some modern arcmagmasby melting of young subducted lithosphere[J].Natrue, 1990, 347:662-665. doi: 10.1038/347662a0 CrossRef Google Scholar
[3]	张旗, 王焰, 钱青, 等.中国东部中生代埃达克岩特征及其构造-成矿意义[J].岩石学报, 2001, 17(2):236-244. Google Scholar
[4]	Chung S L, Liu D Y, Ji J, et al.Adakites from continental collisionzones:Melting of thickened lower crust beneath southern Tibet[J].Geology, 2003, 31:1021-1024. doi: 10.1130/G19796.1 CrossRef Google Scholar
[5]	翟明国.埃达克岩和大陆下地壳重熔的花岗岩类[J].岩石学报, 2004, 20(2):193-194. Google Scholar
[6]	Gao S, Rudnick R L, Yuan H L, et al.Recycling lower continentalcrust in the North China craton[J].Nature, 2004, 432:892-897. doi: 10.1038/nature03162 CrossRef Google Scholar
[7]	李光明, 苪宗瑶.西藏冈底斯成矿带斑岩铜矿的成岩成矿年龄[J].大地构造与成矿学, 2004, 28(2):166-170. Google Scholar
[8]	杨志明, 谢玉玲, 李光明, 等.西藏冈底斯斑岩铜矿带厅宫铜矿床流体包裹体研究[J].矿床地质, 2005, 24(6):584-594. Google Scholar
[9]	杨志明, 谢玉玲, 李光明, 等.西藏冈底斯斑岩铜矿带成矿流体的扫描电镜(能谱)约束——以驱龙和厅宫矿床为例[J].矿床地质, 2006, 25(2):148-154. Google Scholar
[10]	Ji W Q, Wu F Y, Chung S L, et al.Zircon U-Pb geochronology and Hf isotopic constraints on petrogenesis of the Gangdese batholiths, southern Tibet[J].Chemical Geology, 2009, 262(3/4):229-245. Google Scholar
[11]	朱弟成, 王青, 赵志丹, 等.岩浆岩定量限定陆-陆碰撞时间和过程的方法和实例[J].中国科学:地球科学, 2017, 47(6):150-156. Google Scholar
[12]	潘桂棠.青藏高原及邻区大地构造图及说明书[M].北京:地质出版社, 2013. Google Scholar
[13]	Liu Y S, Hu Z C, Zong K Q, et al.Reappraisement and refinement of zircon U-Pb isotope and trace element analyses by LA-ICP-MS[J].Science Bulletin, 2010, 55(15):1535-1546. doi: 10.1007/s11434-010-3052-4 CrossRef Google Scholar
[14]	侯振辉, 王晨香.电感耦合等离子体质谱法测定地质样品中35种微量元素[J].中国科学技术大学学报, 2007, 37(8):940-944. Google Scholar
[15]	Crofu F, Hanchar J M, Hoskin P W O, et al.Atlas of zircon textures[J].Reviews in Mineralogy and Geochemistry, 2003, 53(1):469-500. doi: 10.2113/0530469 CrossRef Google Scholar
[16]	吴元保, 郑永飞.锆石成因矿物学研究及其对U-Pb年龄解释的制约[J].科学通报, 2004, 49(16):1589-1604. Google Scholar
[17]	Le Bas M, Le Maitre R W, Streckeisen A, et al.A chemical classification of volcanic rocks on the total alkali-silica diagram[J].Journal of Petrology, 1986, 27(3):745-750. doi: 10.1093/petrology/27.3.745 CrossRef Google Scholar
[18]	Wright J B.A simple alkalinity ratio and its application to questions of non-orogenic granite genesis[J].Geol.Mag., 1969, 106:370-384. Google Scholar
[19]	Irvine T N, Baragar W R.A Guide to the Chemical Classification of the Common Volcanic Rocks[J].Canadian Journal of Earth Sciences, 1971, 8(5):523-548. doi: 10.1139/e71-055 CrossRef Google Scholar
[20]	Maniar P D, Piccoli P M.Tectonic discrimination granimids[J].Geological Society of America Bulletin, 1989, 101:635-643. doi: 10.1130/0016-7606(1989)101<0635:TDOG>2.3.CO;2 CrossRef Google Scholar
[21]	莫宣学, 赵志丹, 邓晋福, 等.印度-亚洲大陆主碰撞过程的火山作用影响[J].地学前缘, 2003, 10(3):136-147. Google Scholar
[22]	Boynton W V.Cosmochemistry of the rare earth elements:meteoricstudies[J].Rare Earth Element Geochemistry, 1984, 5(2):63-114. Google Scholar
[23]	Sun S S, McDonough W F.Chemical and isotopic systematics ofoceanic basalts: Implications for mantle composition and processes[C]//Saunders A D, Norry M J.Magmatism in Ocean Basins.London: Geological Society of London, 1989, 42(1): 313-345. Google Scholar
[24]	董国臣, 莫宣学, 赵志丹, 等.拉萨北部林周盆地林子宗火山岩层序新议[J].地质通报, 2005, 24(6):549-557. Google Scholar
[25]	付文春, 康志强, 潘会彬.西藏冈底斯带西段狮泉河地区林子宗群火山岩地球化学特征、锆石U-Pb年龄及地质意义[J].地质通报, 2014, 33(6):850-859. Google Scholar
[26]	Martin H.Adakitic magmas:Modern analogues of Archaean granitoids[J].Lithos, 1999, 46(3):411-429. doi: 10.1016/S0024-4937(98)00076-0 CrossRef Google Scholar
[27]	张旗, 许继峰, 王焰, 等.埃达克岩的多样性[J].地质通报, 2004, 23(9):959-965. Google Scholar
[28]	朱弟成, 段丽萍, 廖忠礼, 等.两类埃达克岩(Adakite)的判别[J].矿物岩石, 2002, 22(3):5-9. Google Scholar
[29]	Muir R J, Weaver S D, Bradshaw J D, et al.The Cretaceous separationpoint batholith, New Zealand:Granitoid magmas formed by meltingof mafic lithosphere[J].J.Geol.Soc.London, 1995, 152:689-701. doi: 10.1144/gsjgs.152.4.0689 CrossRef Google Scholar
[30]	Petford N, Atherton M.Na-rich partial melts from newly underplat-ebasalic crust:The Cordillera Blanca batholith[J].Peru J. Petrology, 1996, 37:1491-1521. doi: 10.1093/petrology/37.6.1491 CrossRef Google Scholar
[31]	Gao S, Rudnick R L, Yuan H L, et al.Recycling lower continental crust in the North China craton[J].Nature, 2004, 432:892-897. doi: 10.1038/nature03162 CrossRef Google Scholar
[32]	孟繁一, 赵志丹, 朱弟成, 等.西藏冈底斯东部门巴地区晚白垩世埃达克质岩的岩石成因[J].岩石学报, 2010, 26(7):2181-2190. Google Scholar
[33]	孙书勤, 汪云亮, 张成江.玄武岩类岩石大地构造环境的Th、Nb、Zr判别[J].地质评论, 2003, 49(1):40-47. Google Scholar
[34]	Defant M J, Xu J F, Kepezhinskas P, et al.Adakaits:Some variationson a theme[J].Acta Petrologica Sinica, 2002, 18(2):129-142. Google Scholar
[35]	Chung S L, Chu M F, Ji J Q, et al.The nature and timing of crustal thickening in Southern Tibet:geochemical and zircon Hf isotopicconstraints from post-collisional adakites[J].Tectonophysics, 2009, 477(1/2):36-48. Google Scholar
[36]	张运昌, 陈彦, 杨青, 等.西藏冈底斯带中部南木林地区林子宗群火山岩锆石U-Pb年龄和地球化学特征[J].地质通报, 2019, 38(5):719-732. Google Scholar
[37]	刘安琳, 朱弟成, 王青, 等.藏南米拉山地区林子宗火山岩LA-ICP-MS锆石U-Pb年龄和起源[J].地质通报, 2015, 34(5):826-833. Google Scholar
[38]	谢克家, 曾令森, 刘静, 等.藏南昂仁县桑桑地区林子宗群火山岩的形成时代和地球化学特征[J].地质通报, 2011, 30(9):1339-1352. Google Scholar
[39]	岳雅慧, 丁林.西藏林周基性岩脉的⁴⁰Ar/³⁹Ar年代学、地球化学及其成因[J].岩石学报, 2006, 22(4):855-866. Google Scholar
[40]	李皓杨, 钟孙霖, 王彦斌, 等.藏南林周盆地林子宗火山岩的时代、成因及其地质意义:锆石U-Pb年龄和Hf同位素证据[J].岩石学报, 2007, 23(2):493-500. Google Scholar
[41]	Lee H Y, Chung S L, Lo C H, et al.Eocene Neotethyan slab break off in southern Tibet inferred from the Linzizong volcanic record[J].Tectonophysics, 2009, 477:20-35. doi: 10.1016/j.tecto.2009.02.031 CrossRef Google Scholar
[42]	Wen D R, Liu D Y, Chung S L, et al.Zircon SHRIMP U-Pb ages of the Gangdese Batholith and implications for Neotethyan subduction in southern Tibet[J].Chemical Geology, 2008, 252:191-201. doi: 10.1016/j.chemgeo.2008.03.003 CrossRef Google Scholar
[43]	Rapp R P, Watson E B.Dehydration melting of metabasalt at 8-32 kbar:Implications for continental growth and crust-mantle recycling[J].Journal of Petrology, 1995, 36(4):891-931. doi: 10.1093/petrology/36.4.891 CrossRef Google Scholar
[44]	许继峰, 王强.Adakitic火成岩对大陆地壳增厚过程的指示:以青藏北部火山岩为例[J].地学前缘, 2003, 12(5):401-406. Google Scholar
[45]	张旗.关于C型埃达克岩成因的再探讨[J].岩石矿物学杂志, 2011, 30(4):739-747. Google Scholar