Petrogenesis of Mesozoic granitoids and volcanic rocks in south China : a response to tectonic evolution.
Petrogenesis of Mesozoic granitoids and volcanic rocks in south China : a response to tectonic evolution.
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DOI：
10.18814/epiiugs/2006/v29i1/004
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发表时间：
2006-03
期刊：
影响因子：
3.1
通讯作者：
Xinmin Zhou;T. Sun;W. Shen;L. Shu;Y. Niu
中科院分区：
文献类型：
--
作者：
Xinmin Zhou;T. Sun;W. Shen;L. Shu;Y. Niu
本文总结了华南中生代花岗岩类和火山岩成因研究的新成果。作者认为，这些岩石是早中生代（T1-T3）广泛特提斯造山域内印支造山带陆-陆碰撞后区域构造体制变化的时空响应（第I期）为燕山期造山运动与古陆北西-北西西向俯冲的结果，晚中生代（J2-K2）太平洋岩石圈（II期）印支Ⅰ期花岗岩类早期（T1-T21）为同碰撞型，形成于挤压环境，晚期（T22-T3）为晚碰撞型，形成于局部拉张环境。在燕山Ⅱ期岩浆活动中，燕山早期（J2-J3）花岗岩类火山岩主要分布在南岭和华南构造块体内部，具有裂谷型板内岩浆活动特征，而燕山晚期（K1）花岗岩类火山岩则在成因上代表了活动大陆边缘岩浆活动。K2拉斑玄武岩与红层夹层被解释为与SCB内部弧后伸展盆地的发育有关。华南地区广泛分布着燕山期的花岗岩类火山岩，反映了华南造山带大部分地区的伸展构造。拉张作用引起的地壳深部熔融和幔源玄武质熔体的底侵作用是华南燕山期花岗质岩浆活动的两种主要驱动机制。
This paper summarizes the new results on the petrogenesis of Mesozoic granitoids and volcanic rocks in South China. The authors propose that these rocks were formed in time and space as a response to regional tectonic regime change from the continent-continent collision of the Indosinian orogeny within the broad Tethyan orogenic domain in the Early Mesozoic (T1–T3) (Period I) to the largely extensional setting as a result of the Yanshanian orogeny genetically associated with the NW–WNW-ward subduction of the paleo-Pacific oceanic lithosphere in the Late Mesozoic (J2–K2) (Period II). Of the Period I Indosinian granitoids, the early (T1–T21) ones are syn-collisional, and formed in a compressional setting; the late (T22–T3) ones are late-collisional, and formed in a locally extensional environment. During the Period II Yanshanian magmatism, the Early Yanshanian (J2–J3) granitoid-volcanic rocks, which are distributed mainly in the Nanling Range and in the interior of the South China tectonic block (SCB), are characteristic of rift-type intraplate magmatism, whereas the Late Yanshanian K1 granitoid-volcanic rocks are interpreted as genetically representing active continental margin magmatism. The K2 tholeiitic basalts interlayered with red beds are interpreted as genetically associated with the development of back-arc extensional basins in the interior of the SCB. The Yanshanian granitoid-volcanic rocks are distributed widely in South China, reflecting extensional tectonics within much of the SCB. The extension-induced deep crustal melting and underplating of mantle-derived basaltic melts are suggested as the two principal driving mechanisms for the Yanshanian granitic magmatism in South China.