Tectonosedimentary evolution of the deep Iberia-Newfoundland margins:: Evidence for a complex breakup history
Tectonosedimentary evolution of the deep Iberia-Newfoundland margins:: Evidence for a complex breakup history
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DOI：
10.1029/2006tc001970
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发表时间：
2007-04-06
期刊：
影响因子：
4.2
通讯作者：
Sawyer, Dale S.
中科院分区：
文献类型：
--
作者：
Peron-Pinvidic, Gwenn;Manatschal, Gianreto;Sawyer, Dale S.
关于深裂陷边缘的沉积结构和构造演化的大多数概念性观点都是基于陆内裂陷盆地或近缘，这两种盆地都只经历了少量的地壳减薄。在本文中，我们调查的构造沉积和地貌构造演化与大陆分裂的高度延伸，深伊比利亚-纽芬兰边缘。结果表明，大陆裂解是一个复杂的时空分布过程。根据测年地震单元和钻孔资料的绘图，我们能够确定两个主要的伸展阶段。在第一个阶段，为提托期Barremian（145 - 128马），变形是有关的地幔岩石的折返，盆地变得年轻的海洋，和断层几何形状的变化，从向上到向下凹导致复杂的沉积结构和盆地的几何形状。第二阶段，最新的Aptian（112马），叠印以前挖出的地幔和增生的少年洋壳超过200公里，导致形成的基底高点。观察到的复杂的解体历史挑战经典的裂谷概念，并导致新的解释深裂谷边缘的构造沉积演化。
Most of the conceptual ideas concerning sedimentary architecture and tectonic evolution of deep rifted margins are based on either intracontinental rift basins or proximal margins, both of which underwent only small amounts of crustal thinning. In this paper, we investigate the tectonosedimentary and morphotectonic evolution related to continental breakup of the highly extended, deep Iberia-Newfoundland margins. Our results show that continental breakup is a complex process distributed in time and space. On the basis of mapping of dated seismic units and borehole data we are able to identify two major phases of extension. During a first phase, dated as Tithonian to Barremian (145-128 Ma), deformation is related to exhumation of mantle rocks; basins become younger oceanward, and fault geometry changes from upward to downward concave resulting in complex sedimentary structures and basin geometries. A second phase, dated as latest Aptian (112 Ma), overprints previously exhumed mantle and accreted juvenile oceanic crust over more than 200 km leading to the formation of basement highs. The observed complex breakup history challenges classical concepts of rifting and leads to new interpretations for the tectonosedimentary evolution of deep rifted margins.