首页|新疆库地北喀拉斯坦代里牙一带中元古代石英闪长岩年代学、地球化学特征及地质意义

新疆库地北喀拉斯坦代里牙一带中元古代石英闪长岩年代学、地球化学特征及地质意义

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在库地北喀拉斯坦代里牙一带构造混杂岩中厘定出中元古代石英闪长岩,对其开展地质学、岩石学、岩石地球化学和同位素年代学研究.石英闪长岩SiO2含量54.55%~55.84%,MgO含量5.42%~5.65%,Ti2O含量1.15%~1.57%,Mg#为57~58,里特曼指数σ为1.57~1.80,属高钾钙碱性系列.稀土元素总量∑ REE为150.5×10-6~183.68×10-6;(La/Yb)N为 1.98~2.27,(La/Sm)N为 1.39~2.08,(Gd/Yb)N为 1.00~1.01,δEu=1.03~1.11.石英闪长岩锆石 U-Pb年龄为(1 130.3±5.6)Ma.西昆仑库地北喀拉斯坦代里牙一带石英闪长岩形成时代为中元古代晚期,属赞岐类高镁闪长岩,由地幔橄榄岩与消减洋片反应形成,形成于大陆岛弧环境,是Rodinia超大陆聚合过程洋壳向塔里木板块俯冲消减的地质记录.
Chronology,Geochemical Characteristics and Geological Significance of Middle Proterozoic Quartz Diorite in the Kalasitandaliya Area of Northern Kudi,Xinjiang
Previous scholars have insufficient understanding of the pre Cambrian magmatic activity and tectonic evolu-tion in the northern margin of the West Kunlun Mountains,resulting in significant differences.The author identified the Middle Proterozoic quartz diorite in the tectonic melange of the Kalastandailiya area in Kudi,and conducted geological,petrological,geochemical,and isotopic dating studies on it.The SiO2 content of quartz diorite ranges from 54.55%to 55.84%,MgO ranges from 5.42%to 5.65%,Ti2O content ranges from 1.15%to 1.57%,Mg# ranges from 57%to 58%,and the Rittmann index σ ranges from 1.57 to 1.80,belonging to the high potassium calcium alkaline series.The total amount of rare earth elements ∑ REE ranges from 150.5 to 183.68 ×10-6;(La/Yb)N ranges from 1.98 to 2.27,(La/Sm)N ranges from 1.39 to 2.08,and(Gd/Yb)N ranges from 1.00 to 1.01,δEu ranges from1.03 to 1.11.The U-Pb age of zircon obtained from quartz diorite is 1130.3±5.6 Ma.The formation of quartz diorite in the northern Kalastandailiya area of Ku-di in the western Kunlun Mountains dates back to the late Mesoproterozoic era,belonging to the Zanqi type high magne-sium diorite.It was formed by the reaction of mantle peridotite and subducted ocean sheets,and was formed in continen-tal island arc environment.It is the geological record of the subduction and subduction of oceanic crust towards the Tarim block during the Rodinia supercontinent aggregation process.

West KunlunSouth Kunlun BlockRodinia supercontinentMiddle ProterozoicQuartz dioriteSubduc-tion subduction

白春东、张新征、李典

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河北省区域地质调查院,河北廊坊 065000

西昆仑 南昆仑地块 Rodinia超大陆 中元古代 石英闪长岩 俯冲消减

新疆国土资源厅新疆叶城县库地东1∶5万区域地质矿产调查项目

XJDKJJZ2011-4

2024

新疆地质
新疆维吾尔自治区地质学会

新疆地质

CSTPCD
影响因子:0.879
ISSN:1000-8845
年,卷(期):2024.42(1)
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