Evolution of the eastern Indian Ocean since the Late Cretaceous: Constraints from Geosat altimetry
Evolution of the eastern Indian Ocean since the Late Cretaceous: Constraints from Geosat altimetry
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DOI：
10.1029/jb094ib10p13755
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发表时间：
1989-10
影响因子：
--
通讯作者：
J. Royer;D. Sandwell
中科院分区：
文献类型：
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作者：
J. Royer;D. Sandwell
我们提出了一个从晚白垩世至今东印度洋构造演化的新模型。使用了两类数据来改进先前发表的重建结果。首先，对澳大利亚与南极洲之间以及沃顿盆地的海底磁异常的最新重新解释，对扩张速率和主要重组的时间提供了新的约束条件。其次，从22个地球卫星高度计数据重复周期得出的垂直挠曲剖面（即水平重力异常），揭示了与断裂带相关的构造结构。这些新的地球卫星数据对古扩张方向提供了严格的约束。例如，从塔斯马尼亚岛南部到南极洲乔治五世盆地可以追踪到三个显著的断裂带，这对晚始新世澳大利亚和南极洲的相对运动提供了一个重要的约束。此外，地球卫星剖面被用于确定澳大利亚和南极洲的共轭大陆边缘以及大陆 - 海洋边界，以及凯尔盖朗高原和布鲁肯岭的共轭裂谷边缘。基于对克罗泽盆地、中印度洋盆地、沃顿盆地以及澳大利亚 - 南极盆地的磁异常数据的汇编，提出了十个板块构造重建。在年代5（1100万年）、6（2100万年）、13（3600万年）和18（4300万年）的重建证实，自年代18以来，东南印度洋脊作为一个单一的板块边界。地球卫星数据的约束条件改善了在年代20（4600万年）时凯尔盖朗高原和布鲁肯岭的拟合情况。为了避免布鲁肯岭和凯尔盖朗高原在分裂之前发生重叠，我们的模型包括了凯尔盖朗高原北部和南部区域之间的相对运动。最后，我们研究了我们的模型对印度、澳大利亚和南极洲的相对运动在凯尔盖朗高原和布鲁肯岭以及相邻的纳闽盆地和迪亚曼蒂纳带的构造演化方面的影响，以及东经九十度海岭和凯尔盖朗高原在一个固定热点上的就位情况。
We propose a new model for the tectonic evolution of the eastern Indian Ocean from the Late Cretaceous to the present. Two types of data are used to improve previously published reconstructions. First, recent reinterpretations of seafloor magnetic anomalies, between Australia and Antarctica and in the Wharton Basin, provide new constraints on spreading rates and the timing of major reorganizations. Second, vertical deflection profiles (i.e., horizontal gravity anomaly), derived from 22 repeat cycles of Geosat altimeter data, reveal the tectonic fabric associated with fracture zones. These new Geosat data provide tight constraints on paleospreading directions. For example, three prominent fracture zones can be traced from south of Tasmania to the George V Basin, Antarctica, providing an important constraint on the relative motions of Australia and Antarctica through the Late Eocene. In addition, the Geosat profiles are used to locate the conjugate continental margins and continent-ocean boundaries of Australia and Antarctica, as well as the conjugate rifted margins of Kerguelen Plateau and Broken Ridge. Based on a compilation of magnetic anomaly data from the Crozet Basin, the Central Indian Basin, the Wharton Basin and the Australian-Antarctic Basin, ten plate tectonic reconstructions are proposed. Reconstructions at chrons 5 (11 Ma), 6 (21 Ma), 13 (36 Ma) and 18 (43 Ma) confirm that the Southeast Indian Ridge behaved as a single plate boundary since chron 18. The constraints from the Geosat data provide an improvement in the fit of the Kerguelen Plateau and Broken Ridge at chron 20 (46 Ma). To avoid overlaps between Broken Ridge and the Kerguelen Plateau prior to their breakup, our model includes relative motions between the northern and southern provinces of the Kerguelen Plateau. Finally, we examine the implications of our model for the relative motions of India, Australia and Antarctica on the tectonic evolution of the Kerguelen Plateau and Broken Ridge, and the adjacent Labuan Basin and Diamantina Zone, as well as the emplacement of the Ninetyeast Ridge and the Kerguelen Plateau over a fixed hot spot.