本文選題：內(nèi)蒙古黃花灘銅鎳礦區(qū) + 輝長巖�。� 參考：《巖礦測試》2016年02期

【摘要】：在烏拉特后旗—達茂旗—四子王旗一帶的內(nèi)蒙古中部地區(qū)分布著超基性-酸性連續(xù)巖漿系列,開展其巖體年代學、地球化學研究可為內(nèi)蒙古中部地區(qū)與超基性-基性巖有關(guān)的銅鎳礦成礦規(guī)律研究提供基礎(chǔ)地質(zhì)資料,還可以推斷巖漿侵位時期的區(qū)域大地構(gòu)造背景。本文以達茂旗黃花灘銅鎳礦區(qū)出露的輝長巖為研究對象,采用LA-ICP-MS儀器對無裂隙、高透明度、陰極發(fā)光均勻、環(huán)帶清晰的鋯石進行U-Pb定年,獲得巖體加權(quán)平均年齡為262.4±1.1 Ma,并利用XRF和ICP-MS進行巖石地球化學分析顯示黃花灘輝長巖具有后碰撞拉伸環(huán)境下的巖漿特征。綜合前人相關(guān)研究認為,內(nèi)蒙古中部地區(qū)于中二疊世晚期(255~275 Ma)已經(jīng)進入后碰撞構(gòu)造階段,而古亞洲洋在該區(qū)域的閉合應(yīng)發(fā)生在晚二疊世前(~285 Ma),此結(jié)論豐富了古亞洲洋閉合時間上限及中晚二疊世期間內(nèi)蒙古中部地區(qū)構(gòu)造背景方面的證據(jù)。
[Abstract]:In the central part of Inner Mongolia, the ultrabasic-acid continuous magma series is distributed in the area of Wulatou Banner, Damao Banner and Siziwang Banner, and its geochronology is carried out. The geochemical study can provide basic geological data for the study of copper-nickel metallogenic regularity related to ultrabasic-basic rocks in the central part of Inner Mongolia, and can also infer the regional tectonic setting during the magmatic emplacement period. In this paper, the exposed gabbro from Huanghuatan Copper and Nickel Mine of Damao Banner is taken as the research object. The zircon with no fissure, high transparency, uniform cathodic luminescence and clear annulus is used for U-Pb dating by using LA-ICP-MS instrument. The weighted mean age of the rock mass is 262.4 鹵1. 1 Ma.The geochemistry analysis by XRF and ICP-MS shows that the Huanghuatan gabbro has the characteristics of magma in the post-collisional extensional environment. Based on previous studies, it is concluded that the central part of Inner Mongolia has entered the post-collision tectonic stage since the late Middle Permian. The closure of the Paleo-Asian Ocean in the region should have occurred at 285 Mai before the late Permian. This conclusion enriches the upper limit of the closure time of the Paleo-Asian Ocean and the evidence of tectonic setting in the central part of Inner Mongolia during the Middle and late Permian.
【作者單位】： 中國地質(zhì)科學院研究生部;中國地質(zhì)調(diào)查局天津地質(zhì)礦產(chǎn)研究所;內(nèi)蒙古自治區(qū)地質(zhì)調(diào)查院;中國地質(zhì)科學院地質(zhì)研究所;
【基金】：國家國際科技合作項目(2012DFB20220) 中國地質(zhì)調(diào)查局項目(1212010561510,1212010811061)
【分類號】：P597.3;P618.41;P618.63
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本文編號：1930674