Geodynamic patterns of ophiolites and marginal basins in the Indonesian and New Guinea regions
Geodynamic patterns of ophiolites and marginal basins in the Indonesian and New Guinea regions
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DOI：
10.1144/gsl.sp.2003.218.01.25
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
R. Harris
中科院分区：
文献类型：
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作者：
R. Harris
摘要 对印度尼西亚和新几内亚地区蛇绿岩的空间、时间、地质和地球化学模式的分析表明，与边缘盆地的发育和闭合有很强的相关性。蛇绿岩的空间分布多与盆地边缘斜交碰撞产区有关。这些区域中的应变划分在几个独立移动的岩石圈块之间产生了一系列短暂的板块边界。板块运动的变化和碰撞引起的地幔挤压不断破坏块体之间的扩散边界，产生的空间迅速被俯冲带上部板块中的新洋盆所填充。这些盆地的俯冲带（SSZ）扩张因逃离碰撞缝合带的软流圈的幕式挤压而增强。边缘盆地和蛇绿岩年龄的时间分布反映了各种闭合事件和全球板块运动的变化。印度尼西亚和新几内亚地区的大多数蛇绿岩板片代表了具有俯冲带成分的海洋岩石圈碎片，如地幔序列的常见难熔岩石化学特征和博尼岩的出现所表明的那样。年龄和成分异质性可能表明一些蛇绿岩体是复合地体。与浮力岩石圈的碰撞将这些海洋盆地的部分区域转变为蛇绿岩。蛇绿岩与边缘盆地之间的联系最强，其中部分活跃扩张的 SSZ 盆地部分表现为碰撞带中的蛇绿岩。
Abstract Analysis of spatial, temporal, geological and geochemical patterns of ophiolites in the Indonesian and New Guinea region indicates a strong correlation with marginal basin development and closure. The spatial distribution of ophiolites is mostly linked with marginal basin producing zones of oblique convergence and collision. Strain partitioning in these zones creates a series of ephemeral plate boundaries between several independently moving lithospheric blocks. Repeated disruption of the diffuse boundaries between the blocks by changes in plate motion and collision-induced mantle extrusion creates space that is rapidly filled by new ocean basins in the upper plate of subduction zones. Suprasubduction zone (SSZ) spreading of these basins is enhanced by episodic extrusion of asthenosphere escaping collisional suture zones. Various closure events and global plate motion changes are reflected in the temporal distribution of marginal basin and ophiolite ages. Most ophiolite slabs in the Indonesian and New Guinea region represent fragments of oceanic lithosphere with a subduction zone component, as indicated by the common refractory petrochemistry of the mantle sequence and occurrence of boninite. Age and compositional heterogeneity may indicate that some ophiolite bodies are composite terranes. Collisions with buoyant lithosphere transform parts of these ocean basins into ophiolites. The connection between ophiolites and marginal basins is strongest where parts of actively spreading SSZ basins are partially represented as ophiolites in collision zones.