本文選題：帕米爾 + 塔什庫爾干�。� 參考：《地質(zhì)論評》2017年03期

【摘要】：塔什庫爾干地區(qū)位于青藏高原西北緣,帕米爾高原東北部,是中國境內(nèi)唯一屬于帕米爾弧形構(gòu)造帶的地區(qū)。然而,對于東北帕米爾地區(qū)新生代巖漿作用的研究相對青藏高原主體的研究薄弱得多。我們對東北帕米爾塔什庫爾干地區(qū)新生代巖漿巖的鋯石U-Pb年代學、地球化學及鋯石Hf同位素組成進行了研究。結(jié)果表明:塔什庫爾干新生代巖體中鋯石U-Pb年齡約為10 Ma。所有樣品顯示高鉀、堿性特征:K_2O(4.39%~11.86%)、AR值為3.07~6.36及A/CNK為0.57~0.81,為高鉀堿性巖。塔什庫爾新生代高鉀堿性巖相對虧損Nb、Ta、Zr、Hf、Ti等高場強元素。巖石具有高的Sr/Y比值,Eu異常不明顯。富集LREE,(La/Yb)_N=40.26~287.59。這些地球化學特征指示了塔什庫爾干高鉀堿性巖可能來源于榴輝巖相加厚下地殼。巖石的ε_(Hf)(t)為-0.83~-8.90,范圍較大,說明其源巖物質(zhì)主要來自地殼。推測新生代印度—亞洲大陸碰撞后,印度板塊持續(xù)向北推進引起帕米爾地殼快速增厚,由于地殼增厚不均以及喀喇昆侖斷裂的向北擴展作用,在中新世中期塔什庫爾干地區(qū)局部范圍內(nèi)巖石圈重力失穩(wěn)并發(fā)生垮塌,下地殼發(fā)生部分熔融形成高鉀堿性巖漿。
[Abstract]:The Tashkurgan region is located on the northwest margin of the Qinghai-Tibet Plateau and northeast of the Pamir Plateau. It is the only region in China that belongs to the Pamir arc tectonic belt. However, the study of Cenozoic magmatism in Pamirs in Northeast China is much weaker than that in the main body of Qinghai-Tibet Plateau. Zircon U-Pb geochronology, geochemistry and HF isotopic composition of zircon from Cenozoic magmatic rocks in Pamir Tashkorgan area, Northeast China, have been studied. The results show that the U-Pb age of zircon in the Tashkurgan Cenozoic is about 10 Ma. All the samples showed high potassium and alkaline characteristics: K _ 2O 4.39 ~ 11.86 and AR = 3.07 ~ 6.36 and A/CNK = 0.57 ~ 0.81, respectively, which is a high-potassium alkaline rock. The Cenozoic high-potassium alkaline rocks in Tashkur are relatively depleted in high field strength elements such as NB ~ (2 +) ~ (2 +) ~ (2 +) ~ (2 +) ~ (2 +) ~ (2) ~ ( The rocks have high Sr/Y ratio and EU anomaly is not obvious. Enriched LREE / Yb / N 40.26 / 287.59. These geochemical characteristics indicate that the high potassium alkaline rocks in Tashkurgan may have originated from the lower crust thickened by the durgite facies. The range of 蔚 -0.83 ~ 8.90 for the rocks is -0.83 ~ 8.90, indicating that the source rocks are mainly derived from the crust. It is inferred that after the Cenozoic Indo-Asian continental collision, the Indian plate continued to push northward, resulting in rapid thickening of the Pamir crust, due to uneven crustal thickening and the northward expansion of the Karakoram fault. In the middle Miocene Tashkurgan area, the lithospheric gravity instability occurred and collapsed, and the lower crust partially melted to form high potassium alkaline magma.
【作者單位】： 中國地質(zhì)大學(北京)能源學院;中國地質(zhì)科學院地質(zhì)研究所;南京大學地球科學與工程學院;
【基金】：國家自然科學基金資助項目(編號:41302166;41472198及41430212) 中國地質(zhì)調(diào)查局項目(編號:1211302108022;12120115027001及12120115002101)的成果~~
【分類號】：P588.15

【相似文獻】

相關(guān)期刊論文 前2條

1 年武強;謝月橋;馮昌榮;;西昆侖塔什庫爾干地區(qū)1∶5萬航磁異常特征及找礦前景[J];西部探礦工程;2014年09期

2 ;[J];;年期

，

本文編號：1826494