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东南太平洋海底扩张(方向和速率)的演变,与安第斯构造走向、深成岩活动事件,以及同较长的引张期交替的各次短期挤压性造山阶段有着密切的关系。造山期与速率相对高的板块会聚初期相符,在一些相对“静止”期后马上出现的周期是:110—85,76—70,63—60,49—45,35—33,16—13,7(百万年)。一些大洋构造(如无震海脊或断裂带),可产生“弱的”贝尼奥夫带(浅的,不太明显的),无相应的火山活动。另一方面,古大陆构造(如前寒武纪-古生代造山带)则曾有火山活动和平直的、深而发育良好的贝尼奥夫带。
The evolution of the seabed expansion (direction and velocity) in the southeastern Pacific Ocean is closely related to the Andean tectonic movement, the events of deep diagenesis, and the various short-term crustal orogenies alternated with the longer extension period. The orogeny coincides with the initial convergence of plates at relatively high rates, and the periods that appear immediately after some relatively “quiescent” periods are: 110-85, 76-70, 63-60, 49-45, 35-33, 16-13, 7 (millions of years). Some oceanic structures (such as seismogenic ridges or faults) can produce “weak” Benioff bands (shallow, less obvious) with no corresponding volcanic activity. On the other hand, ancient continental structures (such as the Precambrian-Paleozoic orogenic belt) have volcanic activity and straight, deep and well-developed Benioff belts.