Phanerozoic tectonics of the South China Block: Key observations and controversies
Phanerozoic tectonics of the South China Block: Key observations and controversies
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DOI：
10.1016/j.gr.2012.02.019
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发表时间：
2013-05
影响因子：
6.1
通讯作者：
Yuejun Wang;W. Fan;Guowei Zhang;Yanhua Zhang
中科院分区：
文献类型：
--
作者：
Yuejun Wang;W. Fan;Guowei Zhang;Yanhua Zhang
华南陆块中生代构造体制是了解其地球动力学演化和众多矿产形成的关键。尽管在过去的30年里，对于中生代构造活动是太平洋板块俯冲还是陆内改造，以及中古生代的三期构造活动是否是太平洋板块俯冲和陆内改造两个关键问题，（Kwangsian），三叠（印支期）和侏罗纪-白垩纪（燕山期）主要是由构造转换的洋壳俯冲作用，从古特提斯向东太平洋。本文概述了华南板块在中生代构造方面的关键地质观测。现有资料表明，雪丰-江南构造域存在着独特的沉积、岩浆、构造和变质记录。与广西期和印支期构造活动有关的地质特征主要保存在华南板块东部，包括雪峰-江南域以东的扬子地块和华夏地块东部。它们具有强烈的逆冲/平移挤压作用、深熔花岗质岩浆作用、高级变质作用和幼年幔源岩参与程度低的特点。这两个事件的日期是在CA。400- 460 Ma，约为200-250Ma。燕山期构造事件主要表现为从沿海省到雪峰-江南域的1300 km以上的宽岩浆带和从沿海省到四川盆地的2000 km以上的宽变形带。燕山期的I型、S型和A型花岗岩、正长岩和火山岩分别呈斜向和平行于中国东南沿海省份的两种排列。它们主要形成于152- 180 Ma、120-130和87- 107 Ma三个年龄段，峰值分别为158 Ma、125 Ma和93 Ma。燕山期岩浆活动的停滞期与132- 142 Ma的自顶向北西的递进挤压变形期和95- 112 Ma的左旋走滑变形期在时间上重叠。结合观测和争议，提出了华南板块中生代构造演化的地球动力学模式。
The Phanerozoic tectonic regimes of the South China Block (SCB) hold a key to understanding of its geodynamic evolution with respect to formation of numerous mineral resources. Despite long-time debates in the past three decades, there is still no consensus on the two key points whether the Phanerozoic tectonothermal events were due to subduction of the Pacific plate or intracontinental reworking and whether the three periods of tectonothermal events in the middle Paleozoic (Kwangsian), Triassic (Indosinian) and Jurassic–Cretaceous (Yanshanian) are mainly driven by tectonic transition in subduction of the oceanic crust from Paleotethyan in the west to Pacific in the east. This paper presents an overview of key geological observations in the SCB with respect to its Phanerozoic tectonics. Available data show that there are distinctive sedimentary, magmatic, structural and metamorphic records across the Xuefeng-Jiangnan Domain in the SCB. The geological signatures associated with the Kwangsian and Indosinian tectonothermal events are predominantly preserved in the eastern SCB, including the eastern Yangtze and Cathaysia Blocks to the east of the Xuefeng-Jiangnan Domain. They are characterized by strong thrusting/transpression, anatexic granitic magmatism, high-grade metamorphism and the poor involvement of the juvenile mantle-derived rocks. The two events were dated at ca. 400–460Ma and ca. 200–250Ma, respectively. The Yanshanian tectonothermal event is dominantly represented by the development of a wide magmatic belt of exceeding 1300km (from the coastal province to the Xuefeng-Jiangnan Domain) and a broad deformational belt of more than 2000km (from the coastal province to the Sichuan basin). The Yanshanian I-, S- and A-type granites, syenite and volcanic rocks display two arrays, which are oblique and parallel to the coastal provinces of the southeast China, respectively. They were mainly formed at the three age-spans of 152–180Ma, 120–130 and 87–107Ma with the peak of 158Ma, 125Ma and 93Ma, respectively. The stillstand time of the Yanshanian magmatism was temporally overlapped by the deformation time of the top-to-the-NW progressive transpression or sinistral strike-slip at 132–142Ma and 95–112Ma, respectively. In conjunction with the observations and controversies, a geodynamic model is proposed for the Mesozoic tectonic evolution of the SCB.