【摘要】：位于華北克拉通中部造山帶中北段的懷安地體與內(nèi)蒙孔茲巖帶相接,出露高壓麻粒巖和退變榴輝巖等多種高級變質(zhì)巖,是洞悉華北克拉通古元古代構(gòu)造演化歷史的重要窗口。研究區(qū)變質(zhì)表殼巖包括夕線石榴長英質(zhì)片麻巖、石榴長英質(zhì)粒狀巖石以及紫蘇黑云二長片麻巖。陰極發(fā)光圖像特征顯示研究區(qū)樣品的鋯石主要包括碎屑鋯石和變質(zhì)鋯石,其中碎屑鋯石具有巖漿結(jié)晶環(huán)帶,而變質(zhì)鋯石為單顆�；驀@著繼承性碎屑鋯石邊部生長,內(nèi)部結(jié)構(gòu)均勻,Th/U比值較低。鋯石LAICP-MS U-Pb定年結(jié)果與前人研究結(jié)果綜合表明該區(qū)變質(zhì)表殼巖石的碎屑鋯石的207Pb/206Pb年齡主要集中在~2040Ma,其原巖形成時代與孔茲巖帶變泥質(zhì)巖石相近,均為~2.0Ga。變質(zhì)鋯石記錄其變質(zhì)時代為1957~1804Ma,結(jié)合前人對懷安地區(qū)變泥質(zhì)巖和變基性巖變質(zhì)作用和年代學(xué)研究結(jié)果,推測得出1.95~1.92Ga代表了峰期(高壓)麻粒巖相變質(zhì)時代,1.90~1.85Ga代表峰后減壓階段變質(zhì)時代,而1.85~1.80Ga代表退變質(zhì)晚期的時代。懷安地區(qū)變質(zhì)巖石可能卷入了陰山陸塊、鄂爾多斯陸塊以及東部陸塊間的先后碰撞造山過程,并持續(xù)較長時間(1.95~1.80Ga),最終拼貼為統(tǒng)一的整體。
[Abstract]:The Huai'an terrane located in the central part of the North China Craton orogenic belt is connected with the inner Mongolia Kongzi belt, and many kinds of high grade metamorphic rocks, such as high-pressure granulites and retrograde eclogites, have emerged, which are important windows for understanding the ancient tectonic evolution history of the North China Craton Gu Yuan. Metamorphic crust rocks in the study area include pomegranate feldspar gneiss, pomegranate feldspar granulite and perilla biotite gneiss. The characteristics of catholuminescence images show that the zircons in the study area mainly include clastic zircon and metamorphic zircon, among which the clastic zircon has a magmatic crystallization ring, while the metamorphic zircon is single grain or around the edge of inherited clastic zircon. The ratio of Th / U was lower. The results of zircon LAICP-MS U-Pb dating and previous studies show that the 207Pb / 206Pb age of the detrital zircon of the metamorphic epidermal rocks in this area is mainly concentrated at 2040Ma.The age of origin of the zircon is similar to that of the muddy rocks of the Kongzite belt, and they are all of 2.0 Ga. The metamorphic zircon has a metamorphic age of 1957-1804 Ma. combined with previous studies on metamorphism and chronology of argillite and metamorphic rocks in Huai'an area. It is inferred that 1.95 ~ 1.92Ga represents the peak (high pressure) granulite facies metamorphic epoch (1.90- 1.85Ga) representing the post-peak decompression stage metamorphism, while 1.85- 1.80Ga represents the late retrograde metamorphic period. The metamorphic rocks in Huai'an area may have been involved in the collision orogenic process between the Yinshan block, Ordos block and the eastern continent block, which lasted for a long time (1.951.80Ga) and finally collated into a unified whole.
【作者單位】： 中國地質(zhì)科學(xué)院地質(zhì)研究所;天津地質(zhì)礦產(chǎn)研究所;
【基金】：國家自然科學(xué)基金項目(41430210、41502181) 中國地質(zhì)調(diào)查局地質(zhì)大調(diào)查項目(DD20160121) 中國地質(zhì)科學(xué)地質(zhì)研究所基本科研業(yè)務(wù)費(YYWF201703、J1713)聯(lián)合資助
【分類號】：P588.3;P597.3

【相似文獻】

相關(guān)期刊論文 前1條

1 張耀華;高新國;宋昌錦;李星云;;遼寧省巖石地球化學(xué)研究新進展[J];遼寧地質(zhì);1990年03期

，

本文編號：2128129