Evolution of volcanism and magmatism during initial arc stage: constraints on the tectonic setting of the Oman Ophiolite. In Rollinson, H.R., Searle, M.P., Abbasi, I.A., Al-Lazki, A. and Al Kindi, M.H. (eds.), Tectonic Evolution of the Oman Mountains
Evolution of volcanism and magmatism during initial arc stage: constraints on the tectonic setting of the Oman Ophiolite. In Rollinson, H.R., Searle, M.P., Abbasi, I.A., Al-Lazki, A. and Al Kindi, M.H. (eds.), Tectonic Evolution of the Oman Mountains
复制标题
初始弧阶段火山作用和岩浆作用的演化：对阿曼蛇绿岩构造环境的制约。
DOI：
10.1144/sp392.9
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
S.
中科院分区：
文献类型：
--
作者：
Kusano;Y. Hayashi;M.;Adachi;Y.;Umino;S. and Miyashita;S.
在详细的地层学、岩石学和地球化学研究的基础上，研究了阿曼山北部Wadi Bidi地区蛇绿岩的初始弧岩浆活动，该岩浆活动主要由拉斑熔岩-波长岩流-粗砂岩组成。1110 m厚的V2层序被1.0 m厚的沉积层划分为970 m （LV2）下层序和140 m （UV2）上层序。LV2下部以Pahoehoe流为主，上部以片状流为主，上层沉积物稀疏互层，呈柱状塞状。LV2段除存在输水管道外，以流为主的岩相及少量薄层沉积互层表明研究区曾是短时间内发育的火山中心。UV2是由一个2.0 m厚的火山碎屑落层覆盖的宝钢岩片流组成。在V2层序的末端，有少量的博宁质熔岩被厚厚的远洋沉积物覆盖，这表明与俯冲有关的弧火山作用是短暂的，早在蛇绿岩逆冲之前就结束了。
Based on detailed stratigraphy, petrology and geochemistry, the initial arc magmatism of the Oman Ophiolite consisting of tholeiitic lavas followed by boninite flows and tephras is studied in the Wadi Bidi area, northern Oman Mountains. An 1110-m-thick V2 sequence is divided into the lower 970 m (LV2) and upper 140 m (UV2) thick subsequences by a 1.0-m-thick sedimentary layer. Pahoehoe flows dominate in the lower part of the LV2, while the upper part consists mainly of sheet flows with sparse interbedded pelagic sediments and a cylindrical plug. In addition to the presence of a feeder conduit, the flow-dominant lithofacies with a few thin sedimentary interbeds in the LV2 indicates that the study area was the centre of a volcano grown in a short period. The UV2 is composed of boninite sheet flows overlain by a 2.0-m-thick pyroclastic fall deposit. A small amount of boninite lavas at the end of the V2 sequence overlain by thick pelagic sediments suggests that the subduction-related arc volcanism was short lived and terminated long before the ophiolite obduction.