摘要
为了解兴蒙造山带基底属性和多个构造体系演化与叠加历史,系统总结了近年来在基础地质研究中取得的新成果,并利用这些成果讨论了兴蒙造山带的基底属性与演化历史.兴蒙造山带是指我国东北地区古生代构造作用影响的地区,这些地区也遭受了中生代构造作用的叠加与改造.兴蒙造山带主要由微陆块和其间的造山带组成.虽然传统上认为属于前寒武纪结晶基底的地质体主要已解体为古生代和早中生代,但随着新太古代和古元古代地质体的相继发现,以及新生代玄武岩中幔源古元古代橄榄岩包体的发现,可以判定兴蒙造山带内微陆块应具有古老的前寒武纪基底,并且壳幔是耦合的.微陆块内部地壳增生以垂向增生为主,且主要发生在新元古代和中元古代,以及次要的新太古代和古生代.相反,陆块间造山带或岛弧地体的陆壳则以侧向增生为主,且主要发生在新元古代和古生代.额尔古纳地块与兴安地块的拼合发生在早古生代早期;兴安地块与松嫩地块的拼合发生在早石炭世晚期;松嫩地块与佳木斯地块的拼合发生在早古生代晚期,中生代早期又经历了裂解与再闭合的构造演化过程;华北克拉通北缘增生杂岩带与北方微陆块群的最终拼合发生在晚二叠世-中三叠世,古亚洲洋的最终闭合发生在中三叠世,且为剪刀式闭合.晚古生代晚期蒙古-鄂霍茨克大洋板块南向俯冲作用的发生以及早中生代(三叠纪-早侏罗世)的持续南向俯冲,控制了大兴安岭-冀北-辽西地区的岩浆活动,蒙古-鄂霍茨克大洋的闭合发生在中侏罗世,晚侏罗世-早白垩世主要表现为闭合后的伸展环境.古太平洋板块中生代的俯冲起始时间为早侏罗世,晚侏罗世-早白垩世早期东北亚陆缘主要表现为走滑的构造属性和陆缘地体从低纬度到高纬度的构造就位过程,早白垩世晚期-古近纪岩浆作用的向东收缩揭示了古太平洋板块的持续俯冲和俯冲板片的后撤过程,古近纪晚期日本海的打开标志着东北亚陆缘从活动陆缘已经转变为沟-弧-盆体系,并且标志着东亚大地幔楔的形成.
This paper summarizes recent achievements in basic geological studies in NE China, with the aim of understanding the basement nature and the evolution and overprinting processes of multiple tectonic regimes within the Xing'an-Mongolian Orogenic Belt (XMOB). In this paper, the XMOB only includes the northeastern China which influenced by the Paleozoic orogenic processes, where the overprinting and modification of the Mesozoic tectonic processes took place. The XMOB mainly consists of microcontinental massifs and several orogenic belts between them. Although the so-called Precambrian basement has been dated as Paleozoic and Mesozoic terranes, the new discoveries of the Neoarchean and Paleoproterozoic terranes, together with the Paleoproterozoic mantle-derived xenoliths hosted in Cenozoic basalts, indicate that the microcontinental massifs in the XMOB have the Precambrian basement, and the mantle-crust is coupling within the microcontinental massifs. The crustal accretion within the microcontinental massifs mainly happened in the Neoproterozoic and Mesoproterozoic as well as Neoarchean and Paleozoic by vertical accretion. In contrast, the crustal accretion within intercontinental orogenic belts or island arc terranes mainly took place in the Neoproterozoic and Paleozoic by lateral accretion. The amalgamation of the Erguna and Xing'an massifs happened in the Early stage of Early Paleozoic. The collision between the Xing'an and Songnen massifs took place in the late Early Carboniferous. The amalgamation of the Songnen and Jiamusi massifs occurred in the late stage of Early Paleozoic, the breakup and second amalgamation of these two massifs happened in the Early Mesozoic (the Middle Triassic to Early Jurassic). The final collision between the accretionary belt of northern margin of the North China craton and northern massifs took place during the Late Permian to Middle Triassic. The scissor type closure of the Paleo-Asian Ocean finally happened in the Middle Triassic. The southward subduction of the Mongol-Okhotsk oceanic plate happened during the late stage of Late Paleozoic to Early Jurassic, which controlled the magmatic activities in the Great Xing'an Range and northern Hebei-western Liaoning provinces in this period. The closure of the Mongol-Okhotsk Ocean took place in the Middle Jurassic, and the post-closure extensional environment occurred in the Late Jurassic to Early Cretaceous. The onset of subduction of the Paleo-Pacific plate beneath the Eurasia continent took place in the Early Jurassic. The stike-slip tectonic nature in continental margin of northeastern Asia occurred in the Late Jurassic to early Early Cretaceous, resulting in the tectonic emplacement of accretionary complexes in continental margin from low latitude to high latitude. The eastward shrinking of extents of magmatic activities from the late Early Cretaceous to Paleogene reveals the subduction and subsequent roll-back processes of the Paleo-Pacific plate. The opening of the Japan Sea in the Late Paleogene marks the transformation from active continental margin to trench-arc-basin system and the formation of large mantle wedge in eastern Asia.
作者
许文良
孙晨阳
唐杰
栾金鹏
王枫
Xu Wenliang;Sun Chenyang;Tang Jie;Luan Jinpeng;Wang Feng(College of Earth Sciences,Jilin University,Changchun 130061,China;Key Laboratory of Mineral Resources Evaluation in Northeast Asia,Ministry of Natural Resources,Changchun 130061,China)
出处
《地球科学》
EI
CAS
CSCD
北大核心
2019年第5期1620-1646,共27页
Earth Science
基金
国家自然科学基金项目(Nos.41772047
41702051
41330206)
关键词
兴蒙造山带
微陆块
地壳增生与再造
古亚洲洋构造体系
蒙古-鄂霍茨克构造体系
环太平洋构造体系
构造地质
Xing'an-Mongolian Orogenic Belt
microcontinental massif
crustal accretion and reworking
the Paleo-Asian Oceanic tectonic regime
the Mongol-Okhotsk tectonic regime
the circum-Pacific tectonic regime
tectonics