中亚造山带东部微陆块在Columbia—Rodinia超大陆演化中的岩浆—沉积记录  

Magmatic and sedimentary records of Columbia-Rodinia supercontinent cycle in microcontinents within eastern central Asian orogenic belt

作　　者：王志伟 刘振宇 杨振宁 张立杨 王智慧 徐备 李灿清 孙瑜欣 徐引 朱泰昌 WANG Zhiwei;LIU Zhenyu;YANG Zhenning;ZHANG Liyang;WANG Zhihui;XU Bei;LI Canqing;SUN Yuxin;XU Yin;ZHU Taichang(Hebei Key Laboratory of Strategic Critical Mineral Resources,Heibei GEO University,Shijiazhuang,050031;Hebei Province Collaborative Innovation Center for Strategic Critical Mineral Research,College of Earth Sciences,Hebei GEO University,Shijiazhuang,050031;No.209 Geological Party,Geological Bureau of Yunnan Nuclear Industry,Kuming,650000)

机构地区：[1]河北地质大学河北省战略性关键矿产资源重点实验室,石家庄050031 [2]河北地质大学地球科学学院,河北省战略性关键矿产研究协同创新中心,石家庄050031 [3]云南省核工业二〇九地质大队,昆明650000

出　　处：《地质论评》2023年第6期2115-2140,共26页Geological Review

基　　金：国家自然科学基金资助项目(编号:41802053);河北地质大学国家预研项目(编号:KY2023002);河北地质大学科技创新团队项目(编号:KJCXTD-2021-05)的成果。

摘　　要：中亚造山带东部分布有多个具有前寒武纪基底的微陆块(额尔古纳、兴安、松嫩和佳木斯地块),其上存在大量元古宙地质记录,包括2.5~2.4 Ga、1.8 Ga、1.5~1.4 Ga、0.9~0.6 Ga岩浆事件和中—新元古代沉积序列,它们是回答微陆块与Columbia和Rodinia超大陆演化联系和地球中年期演化的关键对象。额尔古纳、兴安和松嫩地块发育相似的2.5~1.8 Ga基底岩石且其间缺少古老的蛇绿岩,它们可能构成了一个联合陆块,其陆核至少在2.7 Ga前已经形成,从华北克拉通北部裂解出去并在其周缘演化,2.5 Ga和1.8 Ga经历了洋陆俯冲作用,未参与克拉通化过程。1.87~1.80 Ga岩浆作用很可能是Columbia超大陆周缘俯冲作用于古老的微陆块之下的产物;兴安地块西部和白乃庙岛弧带1.45~1.32 Ga A型花岗岩—流纹岩组合及其向陆缘Hf同位素持续亏损的趋势与劳伦南部Granite—Rhyolite Province和波罗的克拉通西南Fennoscandia十分相似,可能是Columbia超大陆周缘俯冲后撤伸展的产物,俯冲后撤和陆下地幔上涌共同促进了Columbia超大陆的伸展和裂解。兴安地块西部发育岩石组合、碎屑锆石年龄和Hf同位素变化与格林威尔造山有关的同碰撞和碰撞后沉积序列相似的沉积地层,而且碎屑锆石微量元素和Hf同位素随时代的系统性变化也揭示了1.10~0.98 Ga地壳明显加厚,伴有大量古老地壳物质重熔,0.9~0.8 Ga地壳持续减薄,以古老地壳再造为主,这与Rodinia超大陆聚合阶段格林威尔造山(1080~980 Ma)及随后的垮塌伸展过程基本吻合。松嫩地块东北部954 Ma正长花岗岩很可能是松嫩与佳木斯地块陆—陆碰撞后阶段沉积岩部分熔融的产物,可能代表了Rodinia超大陆碰撞聚合在中亚造山带东部的响应。超大陆周缘前进式俯冲引发佳木斯地块与松嫩—兴安—额尔古纳联合陆块在954 Ma前碰撞拼贴,同时在外缘的佳木斯地块上产生953~939 Ma中钾—高钾钙�In the eastern Central Asian orogenic belt(CAOB),there are several micro-continents with Precambrian basement(e.g.,Erguna,Xing’an,Songnen and Jiamusi blocks),where a large number of Proterozoic geological records occurred,including 2.5~2.4 Ga,1.8 Ga,1.5~1.4 Ga,0.9~0.6 Ga magmatic events and Meso—Neoproterozoic sedimentary sequences.They are the key objects to answer the evolutionary relationship between micro-continents and the Columbia and Rodinia supercontinents and the evolution of the Earth’s middle age.The Erguna,Xing’an and Songnen blocks have similar 2.5~1.8 Ga basement rocks and lack of ancient ophiolite,which may constitute a combined continental block.The ancient nuclear of the block was formed at least before 2.7 Ga.This combined block likely breakup from and evolved on the periphery of the northern North China Craton.The block underwent oceanic slab subduction at 2.5 Ga and 1.8 Ga,and did not participate in the cratonization.The 1.87~1.80 Ga magmatism was probably formed by the peripheral subduction along the edge of Columbia supercontinent beneath the ancient micro-continents.The 1.45~1.32 Ga A-type granite—rhyolite assemblage in western Xing’an Block and Baicaimiao arc belt,and the continuously depeleted trend of Hf isotope to continental margin,are remarkably similar to that in Granite—Rhyolite Province in southern Laurentian,and Fennoscandia in southwestern Baltic Craton.It may be generated by retreating subduction on the periphery of the Columbia supercontinent.Retreating subduction and mantle upwelling beneath supercontinent jointly promoted the extension and breakup of the Columbia supercontinent.The western Xing’an Block developed similar rock assemblages,detrital zircon ages and Hf isotope changes,to the syn-and post-collision sedimentary sequences related to the Grenville orogeny.Moreover,the systematic changes of detrital zircon trace elements and Hf isotopes over time also reveal that the crust thickened significantly from 1.10 to 0.98 Ga,accompanied by dominant partial mel

关 键 词：中亚造山带东部 微陆块 地球中年期 元古宙 Columbia—Rodinia超大陆 聚合和裂解 

分 类 号：P588.11[天文地球—岩石学] P512.2[天文地球—地质学] P534.3