The role of deep basement during continent-continent collision: a review
The role of deep basement during continent-continent collision: a review
复制标题
深层基底在大陆与大陆碰撞过程中的作用：综述
DOI：
10.1144/gsl.sp.2001.184.01.03
复制
发表时间：
2001
期刊：
影响因子：
--
通讯作者：
P. Ryan
中科院分区：
文献类型：
--
作者：
P. Ryan
摘要 构造、地球物理和变质研究表明，碰撞造山运动使地壳增厚两倍或更多。因此，造山带底部的大量大陆物质受到榴辉岩相条件的影响。相平衡导致浮力损失和地壳根部的热力学加热。这种致密的地壳物质可能会部分俯冲，就像在阿尔卑斯山或喜马拉雅山一样，然后消失在系统中。或者，它可能均衡地停留在莫霍面以下，直到在造山崩塌期间部分被挖出，如斯堪的纳维亚喀里多尼德山脉或通拜-大别山脉。残留的造山根可能以地震反射地幔的形式存在，并为随后的威尔逊旋回裂谷提供了场所。这些相变发生的速率可能对造山收缩的数量和持续时间产生深远的缓冲作用。提出了等静压补偿瞬态二维有限元热模型，试图对这些过程施加一些限制。推测是否可以通过单个挖掘出的榴辉岩布丁或通过绘制推覆复合体来了解更多关于造山运动的过程，这是很有趣的。
Abstract Structural, geophysical and metamorphic studies show that collisional orogeny thickens the crust by a factor of two or more. A large volume of continental material at the base of the orogen is, therefore, subject to eclogite facies conditions. Phase equilibration results in a loss of buoyancy and thermodynamic heating of this crustal root. This dense crustal material may be partially subducted, as in the Alps or the Himalayas, and lost to the system. Alternatively, it may rest isostatically below the Moho until it is partially exhumed during orogenic collapse, as in the Scandinavian Caledonides or the Tonbai-Dabie Mountains. Remnant orogenic roots may exist as seismically reflective mantle and provide a locus for subsequent Wilson Cycle rifting. The rate at which these phase transformations take place may have a profound buffering effect on the amount and duration of orogenic contraction. Isostatically compensated transient 2-dimensional finite element thermal models are presented, which seek to place some limits on these processes. It is interesting to speculate whether more is learnt about the process of orogeny from a single exhumed eclogitic boudin or from mapping nappe complexes.