摘要
长江中下游燕山期中酸性岩浆的形成与幔隆带构造叠加和印支期深层拆离作用有关 ,但最终起决定作用的是燕山期 NNE向陡倾左行压扭斜滑深切断裂。由于该组断裂深切地幔隆起 ,促使地幔物质和热流上涌 ,并穿入印支期因拆离作用形成的不同深度的层状岩浆房 ,使岩浆房中的岩浆与壳源重熔岩浆混合。此外 ,沿着陡倾剪切带尚可出现新的局部重熔 ,形成再度混合的脉状岩浆房。区内岩浆的成因、运移上升和侵入定位的构造动力作用是统一的 ,都是压扭构造应力场作用的结果 ;只是在不同深度 ,不同部位 ,不同阶段的不同表现而已。NNE向左旋压扭斜滑断裂是本区驱动岩浆上升和运移的主要因素。
In the middle- lower reaches of the Yangtze River,Yanshanian intermediate- acidic magma is related to superposed action of mantle swell and deep inter- lithospherical detachmentin Indosinian,but sinistral high- angle transpressional faults in Yanshanian are the deciing factor.Because the faults cutoff the mantle swell, lead to the mantle material and heat flow rising,and link up the layer magma chambersin differentdepths, the magma in the chambers mingles with the crust melting magma.Moreover,there is local melting along acute shear faultsurface,which formsnew magma chambers.Tectonic force of magmatic genesis,ascentand emplacement is unitedly caused by NNE trend sinistral compresso- shear stress field,but there are different appearances in different depths and periods.The activities of NNE trend transpressional faults are the main force of driving magma to migrate and ascent.
出处
《现代地质》
CAS
CSCD
北大核心
1999年第4期371-377,共7页
Geoscience
基金
受国土资源部地质行业基金! ( 96- 97)项目
地质力学开放研究实验室资助
关键词
花岗岩类
成因动力学
陡倾斜滑断裂
层圈滑移
dynamics of granite genesis
syntectonic emplacement
high angle oblique- slip fault
layer- lithospheric glide
the lower Yangtze River tectonic bel
