A model of volcanogenic sedimentation in marginal basins
A model of volcanogenic sedimentation in marginal basins
复制标题
边缘盆地火山沉积模型
DOI：
10.1144/gsl.sp.1984.016.01.04
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
H. Sigurdsson
中科院分区：
文献类型：
--
作者：
S. Carey;H. Sigurdsson
与大洋岛弧相邻的边缘盆地接受来自边缘火山弧、弧后扩张中心以及较小程度上的残余弧的火山碎屑。火山弧是体积上最重要的来源，与丰富的火山碎屑正在产生的爆炸性陆上和/或水下喷发和弧复合体的二次侵蚀。物质通过水柱被动沉降或通过初次喷发和二次再活动过程产生的各种沉积物重力流向边缘盆地较深部分输送。在弧翼底部的弧源物质的沉积产生厚的火山碎屑裙，并导致盆地内火山沉积物积累的显著不对称。由于弧火山作用对沉积物的性质和向深海的输送的影响，裙岩相是复杂的，与典型的深海扇系统不相似。弧后扩张中心提供少量深水玻璃碎屑岩和热液衍生的火山成因沉积物，这些沉积物被纳入沉积序列的基底部分。火山成因沉积物的分散和沉积受到与边缘盆地演化相关的地质作用的深刻影响，如弧后扩张、断裂和岛弧裂解。
Summary Marginal basins adjacent to oceanic island arcs receive volcaniclastic debris from the bordering volcanic arc, back-arc spreading centre, and, to a lesser degree, the remnant arc. The volcanic arc is volumetrically the most important source, with abundant volcaniclastics being produced by explosive subaerial and/or subaqueous eruptions and secondary erosion of the arc complex. Transport of material to the deeper parts of marginal basins occurs by passive settling through the water column or by a variety of sediment gravity flows generated by primary eruptions and secondary remobilization processes. Deposition of arc-derived material at the base of the arc flank produces thick volcaniclastic aprons and results in a marked asymmetry in the accumulation of volcanogenic sediment within basins. The apron facies are complex and not analogous to typical deep-sea fan systems because of the influence of arc volcanism on the nature and delivery of sediment to the deep sea. Back-arc spreading centres supply a small volume of deep-water hyaloclastites and hydrothermally derived volcanogenic sediments which are incorporated into the basal parts of sedimentary sequences. The dispersal and deposition of volcanogenic sediments are profoundly influenced by geological processes associated with marginal basin evolution such as back-arc spreading, faulting, and island-arc splitting.