The Mesozoic South Atlantic Ocean and evolution of its continental margins
The Mesozoic South Atlantic Ocean and evolution of its continental margins
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中生代南大西洋及其大陆边缘的演化
DOI：
10.1029/jb084ib11p05973
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发表时间：
1979
影响因子：
--
通讯作者：
J. LaBrecque
中科院分区：
文献类型：
--
作者：
P. Rabinowitz;J. LaBrecque
详细比较了南大西洋南部大陆边缘脊顶共轭两侧的重磁异常，并给出了大洋基底与大陆基底边界的模型。研究区域包括阿古拉斯-福克兰断裂带的主要剪切边缘以及阿根廷和南部非洲分别位于格兰德河海隆和沃尔维斯海岭以南的断裂边缘。这些边缘在很大程度上与线性磁异常有关，这些磁异常可以模拟为将海洋基底与大陆基底分开的边缘效应异常。与磁异常相一致的是均衡重力异常中的梯度。我们将这些地球物理线性构造定位在非洲大陆边缘，并将其顺时针旋转，以适应阿根廷大陆边缘的异常。这种拟合为我们提供了南大西洋完全闭合的新极点，在很大程度上消除了在其他重建中观察到的间隙和重叠。因此，改进的拟合表明，在南大西洋南部早期开放期间，刚性板块的行为和大陆地壳的最小拉伸。
Gravity and magnetic anomalies bordering the continental margins of the southern South Atlantic Ocean are compared, in detail, on conjugate sides of the ridge crest, and a model for the boundary between oceanic and continental basement is given. The area of study includes the predominantly sheared margins of the Agulhas-Falkland fracture zone and the rifted margins of Argentina and southern Africa south of the Rio Grande Rise and Walvis Ridge, respectely. These margins have associated with them, for the most part, linear magnetic anomalies that can be modeled as edge effect anomalies separating oceanic from continental basement. Coincident with the magnetic anomalies are gradients in the isostatic gravity anomaly. We have taken the location of these geophysical lineaments on the African margin and rotated them clockwise to fit the anomalies on the Argentine margin. This fit, which gives us a new pole of total closing for the South Atlantic Ocean, obviates, for the most part, the gaps and overlaps observed in other reconstructions. The improved fit thereby suggests rigid plate behavior and minimum stretching of continental crust during the early opening of the southern South Atlantic Ocean.