Petrogenesis and Geological Implications of Late Carboniferous Leucogranites in Harlik Area, Eastern Tianshan

被引：0
|
作者：
Zhu X. [1 ,2 ,3 ]
Zhu T. [1 ]
Zhang X. [1 ]
Xi R. [1 ]
Meng Y. [1 ]
Wang K. [1 ]
机构：
[1] Key Laboratory for the Study of Focused Magmatism and Giant Ore Deposits, Xi'an Center of Geological Survey, China Geological Survey, Xi'an
[2] State Key Laboratory of Continental Dynamics, Northwest University, Xi'an
[3] Department of Geology, Northwest University, Xi'an
来源：
Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences | 2018年 / 43卷 / 12期
关键词：
Geochemistry; Harlik area; LA-ICP-MS U-Pb dating; Leucogranite; Post-collision;
D O I：
10.3799/dqkx.2018.989
中图分类号：
学科分类号：
摘要：
The leucogranite provides key insights into the tectonic evolution of orogenic belt. Petrology, geochemistry and geochronology results show that there are four types of leucogranites in the Xiaopu area in the southern piedmont of the Harlik area, eastern Tianshan, including the biotite leucogranite, two-mica leucogranite, tourmaline-bearing leucogranite and garnet-bearing leucogranite. These leucogranites are rich in silica (SiO2=73.22%-75.12%), aluminium (Al2O3=13.59%-14.49%), alkali(ALK=7.11%-9.67%), but low in titanium (TiO2=0.01%-0.14%), iron(TFeO=0.26%-1.37%), magnesium (MgO=0.09%-0.46%) and calcium (CaO=0.46%-1.92%), which belong to the calc-alkaline to shoshonite peraluminous granite. The high CaO/Na2O (0.46-0.47) and low Rb/Sr (0.31-0.33) ratios of the biotite leucogranite imply that it was formed by the biotite dehydration of greywacke, whereas the low CaO/Na2O (0.11-0.31) and high Rb/Sr (1.41-3.75) ratios indicate that the two-mica and tourmaline-bearing leucogranites were formed by the muscovite dehydration of meta-pelitic-arenaceous sedimentary rocks, and the strong negative Eu anomalies and "seagull forms" REE patterns reveal that the garnet-bearing leucogranite belongs to highly fractionated granite. Considered the geological features and low initial temperature (T=637-644 ℃), the Xiaopu leucogranites were probably formed related to the exhumation of deep material, or extensional collapse of the orogen. Zircon U-Pb results show that the formation ages of biotite and tourmaline-bearing leucogranites are 308.5±2.2 Ma and 307.8±2.3 Ma, respectively. Combining with the previous data, it is suggested that the Harlik area was in extensional tectonic setting in the Late Carboniferous. © 2018, Editorial Department of Earth Science. All right reserved.
引用
收藏
页码：4443 / 4458
页数：15
相关论文
共 57 条
  • [1] Braun I., Raith M., Kumar G.R.R., Dehydration-Melting Phenomena in Leptynitic Gneisses and the Generation of Leucogranites: A Case Study from the Kerala Khondalite Belt, Southern India, Journal of Petrology, 37, 6, pp. 1285-1305, (1996)
  • [2] Brown M., Retrograde Processes in Migmatites and Granulites Revisited, Journal of Metamorphic Geology, 20, 1, pp. 25-40, (2002)
  • [3] Cao F.G., Tu Q.J., Zhang X.M., Et al., Preliminary Determination of the Early Paleozoic Magmatic Arc in the Karlik Mountains, East Tianshan, Xinjiang, China-Evidence from Zircon SHRIMP U-Pb Dating of Granite Bodies in the Tashuihe Area, Geological Bulletin of China, 25, 8, pp. 923-927, (2006)
  • [4] Cao F.G., Zhang Y.P., Li Y., Et al., The Gelogical Character of Nanhuan System Qingshixia Formation Qincheng Hami, Xijiang, Xinjiang Geology, 27, 4, pp. 303-307, (2009)
  • [5] Chen X.J., Shu L.S., Features of the Post-Collisional Tectono-Magmatism and Geochronological Evidence in the Harlik Mt.Xinjiang, Acta Petrologica Sinica, 26, 10, pp. 3057-3064, (2010)
  • [6] Chen X.J., Shu L.S., Santosh M., Late Paleozoic Post-Collisional Magmatism in the Eastern Tianshan Belt, Northwest China: New Insights from Geochemistry, Geochronology and Petrology of Bimodal Volcanic Rocks, Lithos, 127, 3-4, pp. 581-598, (2011)
  • [7] Chen X.J., Zhang K.H., Zhang G.L., Et al., Characteristics, Petrogenesis and Tectonic Implications of the Permian Omoertage Alkaline Granites in Harlik Area, Xinjiang, Acta Petrologica et Mineralogica, 35, 6, pp. 929-946, (2016)
  • [8] Chung S.L., Chu M.F., Zhang Y.Q., Et al., Tibetan Tectonic Evolution Inferred from Spatial and Temporal Variations in Post-Collisional Magmatism, Earth-Science Reviews, 68, 3-4, pp. 173-196, (2005)
  • [9] Gao L.E., Zeng L.S., Fluxed Melting of Metapelite and the Formation of Miocene High-CaO Two-Mica Granites in the Malashan Gneiss Dome, Southern Tibet, Geochimica et Cosmochimica Acta, 130, pp. 136-155, (2014)
  • [10] Gao L.E., Zeng L.S., Hu G.Y., High Sr/Y Two-Mica Granite from Quedang Area, Southern Tibet, China: Formation Mechanism and Tectonic Implications, Geologcal Bulletin of China, 29, 2, pp. 214-226, (2010)
123456