Sedimentation in the Sunda Trench and forearc region
Sedimentation in the Sunda Trench and forearc region
复制标题
巽他海沟和弧前区域的沉积
DOI：
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发表时间：
1982
期刊：
影响因子：
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通讯作者：
F. Emmel
中科院分区：
文献类型：
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作者：
G. Moore;J. Curray;F. Emmel
巽他海沟和弧前区域的沉积作用主要是由印度洋东北部边缘周围的造山带和火山岩的陆源碎屑搬运而成。喜马拉雅石英质碎屑被输送到孟加拉湾，沿着海沟轴线向南一直到巽他海峡。在弧外脊发育之前，大部分弧源沉积物绕过弧前盆地，沉积在海沟中。新近纪期间，几乎所有来自爪哇和苏门答腊岛弧的沉积物都被捕获在弧前盆地中，没有到达海沟。半远洋沉积作用在海沟内坡下部占主导地位。钙质微体化石和火山灰是这些半远洋沉积物的主要成分。在斜坡的高处，陆源和半远洋沉积物堆积在大型沟坡盆地中。Sunda弧前盆地是一系列较小的单个盆地，它们被横向高点彼此分开，隔离了各自的沉积序列。在北苏门答腊外海，石英质碎屑堆积，而在爪哇外海，火山碎屑沉积物占主导地位。沉积物沿海沟轴线的长距离搬运、外弧脊后沉积物的筑坝以及弧前盆地的分段性质，导致不同物源的沉积体并置。
Summary Sedimentation in the Sunda Trench and forearc region is dominated by the transport of terrigenous detritus from orogenic and volcanic terranes around the margins of the north-eastern Indian Ocean. Quartzose Himalayan detritus is transported into the Bay of Bengal and down the trench axis as far south as the Sunda Strait. Prior to development of the outer-arc ridge, the majority of arc-derived sediment bypassed the forearc basin and was deposited in the trench. Nearly all sediment derived from the arc terranes of Java and Sumatra during the Neogene has been trapped in the forearc basin and has not reached the trench. Hemipelagic sedimentation dominates on the lower part of the inner trench slope. Calcareous microfossils and volcanic ash are the dominant constituents of these hemipelagic deposits. Higher on the slope, terrigenous and hemipelagic sediments accumulate in large trench-slope basins. The Sunda forearc basin is a series of smaller individual basins separated from each other by transverse highs, isolating the respective sedimentary sequences. Off north Sumatra, quartzose detritus accumulates, whereas off Java, volcaniclastic sediments predominate. Long-distance transport of sediment down the trench axis, damming of sediments behind the outer-arc ridge, and the segmented nature of the forearc basin leads to the juxtaposition of sediment bodies with different provenances.