Correlations between the Eastern Block of the North China Craton and the South Indian Block of the Indian Shield: an Archaean to Palaeoproterozoic link
Correlations between the Eastern Block of the North China Craton and the South Indian Block of the Indian Shield: an Archaean to Palaeoproterozoic link
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DOI：
10.1016/s0301-9268(02)00212-7
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发表时间：
2003-04
影响因子：
3.8
通讯作者：
Guochun Zhao;M. Sun;S. Wilde
中科院分区：
文献类型：
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作者：
Guochun Zhao;M. Sun;S. Wilde
华北陆块是由东、西陆块沿着横贯华北造山带（TNCO）拼合而成，印度地盾是由南印度陆块和北印度陆块沿着中印度构造带（CITZ）拼合而成。华北陆壳的EB与印度地盾的SIB具有许多相似的岩浆和沉积特征。EB和SIB的早白垩世表壳岩序列均由3.6-3.4Ga（紫红色）石英岩、泥质片麻岩、钙硅酸盐、大理岩、条带状磁性石英岩和斜长角闪岩组成，EB称曹庄群，SIB称老变质群（OMG）。两个地块的中侏罗世组合可划分为早侏罗世和早侏罗世。（3.4-3.3Ga）相，以EB中的陈台沟表壳岩和正片麻岩、SIB中的Holenarsipur表壳岩和Gorur正片麻岩为代表;（3.1-2.9Ga）相，以EB群中的乾安表壳岩、杨崖山正片麻岩和SIB群中的半岛片麻岩为代表。晚侏罗世泰山群及其在EB中的等价物在地层上与SIB中的达尔瓦尔超群相似。此外，无论是EB和SIB的特点是近同期的晚中生代花岗岩类侵入和变质事件。EB和SIB均以穹盆构造为主，晚中生代麻粒岩的变质演化均以逆冲P-T轨迹为特征。两区块古元古代沉积-火山岩分别由下部富碎屑岩、中部富火山岩和上部碎屑岩+碳酸盐岩组成。侏罗纪与古元古代岩浆和沉积记录的强烈相似性表明，EB和SIB可能是曾经是一个大陆的分散残余。一个可能的适合的EB和SIB的重建，其中EB的北方边缘被放置毗邻SIB的西部边缘，与TNCO和WB代表的延续，分别为CITZ和NIB。这种拟合表明，EB+SIB和WB+NIB代表了两个离散的大陆块体，在古元古代碰撞事件期间沿沿着TNCO+CITZ造山带连接。EB和SIB的碎裂可能发生在中元古代的开始，并在1.4Ga，EB和SIB可能已经分离成两个不同的大陆块，证明了在中元古代沉积序列和相关的双峰火山岩在两个块体的显着差异。
Recent tectonometamorphic data reveal that the North China Craton formed by amalgamation of an Eastern Block (EB) and a Western Block (WB) along the Trans-North China Orogen (TNCO), and the Indian Shield formed by amalgamation of the South Indian Block (SIB) and the North Indian Block (NIB) along the Central Indian Tectonic Zone (CITZ). The EB of the North China Craton and the SIB of the Indian Shield share many similar magmatic and sedimentary features. The early Archaean supracrustal sequences in both the EB and SIB consist of 3.6–3.4Ga (fuchsite) quartzites, pelitic gneisses, calc-silicates, marbles, banded magnetic quartzites and amphibolites, called the Caozhuang Group in the EB and the Older Metamorphic Group (OMG) in the SIB. The middle Archaean assemblages in both the blocks can be divided into an early (3.4–3.3Ga) phase, represented by the Chentaigou supracrustal rocks and orthogneisses in the EB and the Holenarsipur supracrustal rocks and the Gorur orthogneisses in the SIB, and a late (3.1–2.9Ga) phase, represented by the Qianan supracrustal rocks and the Yangyashan orthogneiss in the EB and the Sargur Group and the Peninsular gneiss in SIB. The late Archaean Taishan Group and its equivalents in the EB are stratigraphically similar to the Dharwar Supergroup in the SIB. Moreover, both the EB and SIB are characterised by near-contemporaneity of late Archaean granitoid intrusive and metamorphic events. In addition, dome-and-basin structures are dominant in both the EB and SIB, and anticlockwise P–T paths charaterise the metamorphic evolution of the late Archaean granulites in the two blocks. The Palaeoproterozoic sedimentary–volcanic rocks in both blocks comprise lower clastic-rich, middle volcanic-rich and upper clastic+carbonate sequences. The strong resemblance of the Archaean to Palaeoproterozoic magmatic and sedimentary records suggests that it is possible that the EB and SIB are dispersed remnants of what was once a single continent. A possible fit is proposed for the reconstruction of the EB and SIB, where the northern margin of the EB is placed adjacent to the western margin of the SIB, with the TNCO and WB representing the continuations, respectively, of the CITZ and NIB. This fit suggests that the EB+SIB and the WB+NIB represent two discrete continental blocks that joined along the TNCO+CITZ orogen during a Palaeoproterozoic collisional event. Fragmentation of the EB and SIB may have occurred at the beginning of the Mesoproterozoic and, by 1.4Ga, the EB and SIB may have separated into two different continental blocks, as evidenced by striking differences in the Mesoproterozoic sedimentary successions and associated bimodal volcanics in the two blocks.