Geochemistry and geological significance of Indosinian granites in the Ladigongma area of northern segment of the Sanjiang belt,Qinghai
LI Shanping1, LI Yanjing2, REN Hua1, LIN Hao3, JIN Tingting1, DOU Yongbin1
1.Qinghai Province Key Laboratory of Geological Processes and Mineral Resources of Northern Qinghai-Tibetan Plateau,Qinghai Institute of Geological Survey, Xining 810012, China; 2.Seismological Bureau of Qinghai Haidong,Haidong 810600, China; 3.Qinghai University, Xining 810016, China
Abstract：The Ladigongma granite is located in the Tongtian river tectono-magmatic belt of the Xijin Ulan - Jinsha river suture zone. According to the outcrop research, the rock types could be subdivided into 3 units: the Ladigongma granodiorite (T3γδ), the Riariqu quartz diorite (T3δo) and the Mianqie tonalite (T3δi). All of the granites are formed in the Late Triassic. The major elements results show that the granites are rich in silicon, aluminum, alkalis and volatile components; the rare earth elements results show intense fractionation between LREE and HREE with significant LREE enrichment and weak negative of Eu and Ce; and the trace elements are characterized by Rb, Th and Ba enrichment, and Y, Yb and Cr depletion. All of these are the characteristics of I- and S-type peraluminous granite. They have the same geochemical characteristics as the calc-alkaline granite in volcanic arc. It is inferred that the subduction of Duocai—Dangjiang tectonic melange zone in Late Triassic may be responsible for the granites in the study area. The granites are the continental collision type granite and the tectonic setting is subduction-convergent environment.
李善平， 李延京， 任 华， 林 浩， 金婷婷， 窦永斌. 青海三江北段拉地贡玛地区印支期花岗岩地球化学特征及地质意义[J]. 中国地质调查, 2016, 3(1): 35-43.
LI Shanping, LI Yanjing, REN Hua, LIN Hao, JIN Tingting, DOU Yongbin. Geochemistry and geological significance of Indosinian granites in the Ladigongma area of northern segment of the Sanjiang belt,Qinghai. , 2016, 3(1): 35-43.
[1] 黄汲清,陈炳蔚.中国及邻区特提斯海的演化[M].北京:地质出版社,1987:1-105. [2] 刘训.青藏高原不同地体的地层、生物区系及沉积构造演化史[M].北京:地质出版社,1992:2-50. [3] 刘增乾,徐宪,潘桂棠.青藏高原大地构造与形成演化[M].北京:地质出版社,1990:1-174. [4] 王鸿祯,杨森楠,刘本培,等.中国及邻区构造古地理和生物古地理[M].武汉:中国地质大学出版社,1990:3-50. [5] 孙晓猛,简平.滇川西部金沙江古特提斯洋的威尔逊旋回[J].地质论评,2004,50(4):343-350. [6] 莫宣学,沈上越,朱勤文,等.三江中南段火山岩-蛇绿岩与成矿[M].北京:地质出版社,1998:86-167. [7] 孙晓猛,张保民,聂泽同,等.滇西北金沙江带蛇绿岩、蛇绿混杂岩形成环境及时代[J].地质论评,1997,43(2):113-120. [8] 董云鹏,朱炳泉,常向阳,等.哀牢山缝合带中两类火山岩地球化学特征及其构造意义[J].地球化学,2000,29(1):6-13. [9] 王培生.云南德钦蛇绿岩中基性熔岩的岩石化学特征初步研究[G]//青藏高原地质文集编委会.青藏高原地质文集(9).北京:地质出版社,1985:147-209. [10] 王永文,王玉德,李善平,等.西金乌兰构造混杂岩带特征[J].西北地质,2004,37(3):15-20. [11] 陈健,李建放,安勇胜,等.风火山地区西金乌兰湖-金沙江蛇绿构造混杂带的物质组成及发展演化特征[J].西北地质,2007,40(3):36-43. [12] 李善平,潘彤,李永祥,等.青藏高原北羌塘盆地多彩地区蛇绿岩地球化学特征及构造环境[J].中国地质,2010,37(6):1592-1606. [13] 翟庆国,李才,程立人,等.西藏羌塘角木日地区二叠纪蛇绿岩的地质特征及意义[J].地质通报,2004,23(12):1228-1230. [14] 任纪舜,肖黎薇.1∶25万地质填图进一步揭开了青藏高原大地构造的神秘面纱[J].地质通报,2004,23(1):1-11. [15] 王传尚.滇西德钦地区放射虫化石新发现[J].华南地质与矿产,1999,12(2):31-35. [16] 莫宣学,邓晋福,董方浏,等.西南三江造山带火山岩-构造组合及其意义[J].高校地质学报,2001,7(2):121-138. [17] 青海省地质调查院.杂多、治多幅1∶25万区域地质调查报告及图件[R].2005. [18] 李勇,王成善,伊海生.西藏金沙江缝合带西段晚三叠世碰撞作用与沉积响应[J].沉积学报,2003,21(2):191-197. [19] 青海省第二区域地质调查队.1∶20万治多县幅区域地质矿产调查报告[R].1984. [20] Sylvester P J.Post-collisional strongly peraluminous granites[J].Lithos,1998,45(1/4): 29-44. [21] Peccerillo A,Taylor S R.Geochemistry of Eocene calc-alkaline volcanic rocks from the Kastamonu area,northern Turkey[J].Contributions to Mineralogy and Petrology,1976,58(1):63-81. [22] Nakada S,Takahashi M.Regional variation in chemistry of the Miocene intermediate to felsic magmas in the outer zone and the Setouchi province of Southwest Japan[J].The Journal of the Geological Society of Japan,1979,85(9): 571-582. [23] 赵枕华.微量元素地球化学原理[M].北京:科学出版社,1997:113-138. [24] 毛景文,李红艳,裴荣富,等.千里山花岗岩体地质地球化学及与成矿关系[J].矿床地质,1995,14(1):12-25. [25] 肖庆辉,邓晋福,马大铨,等.花岗岩研究思维与方法[M].北京:地质出版社,2002:21-38. [26] 邱瑞龙.九华山花岗岩岩浆分异特征及岩石成因[J].岩石矿物学杂志,1998,17(4):308-315. [27] Harrison M T,Grove M,Mckeegan K D,et al.Origin and episodic emplacement of the Manaslu intrusive complex,central Himalaya[J].Journal of Petrology,1999,40(1): 3-19. [28] 华仁民,张文兰,陈培荣,等.赣南大吉山与漂塘花岗岩及有关成矿作用特征对比[J].高校地质学报,2003,9(4):609-619. [29] Miniar P D,Piccoli P M.Tectonic discrimination of granitoids[J].Geological Society of America Bulletin,1989,101: 635-643. [30] Pearce J A,Harris N B W,Tindle A G.Trace element discrimination diagrams for the tectonic interpretation of granitic rocks[J].Journal of Petrology,1984,25(4): 956-983. [31] Batchelor R A,Bowden P.Petrogenetic interpretation of granitoid rock series using multicationic parameters[J].Chemical Geology,1985,48(1/4): 43-55.
2016, Vol. 3 
