Tectonic development of the North Patagonian Andes and their related Miocene foreland basin (41°30′‐43°S)
Tectonic development of the North Patagonian Andes and their related Miocene foreland basin (41°30′‐43°S)
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北巴塔哥尼亚安第斯山脉及其相关的中新世前陆盆地（41°30′‐43°S）的构造发育
DOI：
10.1029/2011tc003084
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发表时间：
2012
期刊：
影响因子：
4.2
通讯作者：
V. Ramos
中科院分区：
文献类型：
--
作者：
D. Orts;A. Folguera;A. Encinas;Miguel E. Ramos;J. Tobal;V. Ramos
北方巴塔哥尼亚安第斯山脉是通过多种机制形成的，从主安第斯山脉早中侏罗世伸展构造的构造反转到前心地区渐新世。这些作用发生在两个不同的造山阶段，首先是早白垩世晚期，后来是中新世，晚渐新世伸展将这两个收缩期分开，并记录在弧后地区发育的半地堑中。最后一个收缩阶段与中新世晚期弧的东部前陆扩张同时存在，弧的根部目前在主安第斯山脉（位于本弧以东）作为次要的花岗质岩石和火山岩堆暴露。由于这一造山阶段的结果，前陆盆地的发展，从18 Ma的主要北巴塔哥尼亚安第斯山脉，在那里的山前被海侵淹没对应的基础上的Ekrihuau组，到11 Ma的前陆地区。该前陆盆地的蚕食作用首先发生在腹地，然后向前陆带发展。根据生长地层的几何形状推断，隐伏构造在前缘带形成破碎的前陆。在上新世至第四纪，当弧锋收缩到现在的位置时，大部分收缩变形在造山楔中消失。
The Northern Patagonian Andes have been constructed through multiple mechanisms that range from tectonic inversion of extensional structures of Early to Middle Jurassic age in the Main Andes to Oligocene in the Precordilleran region. These have acted during two distinctive orogenic stages, first in late Early Cretaceous and later in Miocene times Late Oligocene extension separates these two contractional periods and is recorded by half‐grabens developed in the retroarc region. The last contractional stage coexists with an eastward foreland expansion of the late Miocene arc whose roots are presently exposed as minor granitic stocks and volcanic piles subordinately in the Main Andes, east of the present arc. As a consequence of this orogenic stage a foreland basin has developed, having progressed from 18 Ma in the main North Patagonian Andes, where the mountain front was flooded by a marine transgression corresponding to the base of the Ñirihuau Formation, to 11 Ma in the foreland area. Cannibalization of this foreland basin occurred initially in the hinterland and then progressed to the foreland zone. Blind structures formed a broken foreland at the frontal zone inferred from growth strata geometries. During Pliocene to Quaternary times most of the contractional deformation was dissipated in the orogenic wedge at the time when the arc front retracted to its present position.