Abstract—

The present study deals with the Jabal Tays ophiolite area, which was affected by Al Amar-Idsas fault. It is one of the most important tectonic features in the Eastern Arabian Shield. This study aims to accomplish through field investigation, finite strain and microstructural analysis for understanding the nature of tectonic evolution and the deformation in the Jabal Tays area. Field and microscopic investigations indicate that mafic-ultramafic rocks at Jabal Tays include the large amount of serpentinite, subordinate amounts of gabbro intruded by mafic dikes, mélange, serpentinite schist, and listwaenite. The serpentinite makes up the bulk of Jabal Tays, is variably sheared and typically consists of relatively massive serpentinite cut by shear zones marked by serpentinite schist. Based on finite strain and microstructural analysis, mafic-ultramafic rocks in the Jabal Tays area are generally confined to brittle-ductile shear zones, which they are sub-parallel to the prevailing NW or NNW structural trends. It is confined mainly to the metamorphic terrains, especially to zones intruded by mafic volcanic rocks. It is concluded that the contacts between the Abt schist and metavolcano-sedimentary rocks were formed during progressive thrusting under brittle to semi-ductile deformation conditions by simple shear that also involved a component of vertical shortening, causing subhorizontal foliation in the Jabal Tays area.

中文翻译：

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沙特阿拉伯东部阿拉伯盾牌Jabal Tays蛇绿岩配合物的应变分析和微结构研究

摘要—

本研究涉及受Al Amar-Idsas断层影响的Jabal Tays蛇绿岩地区。它是阿拉伯东部盾牌最重要的构造特征之一。这项研究旨在通过野外调查，有限应变和微观结构分析来了解Jabal Tays地区的构造演化和变形的本质。野外和显微镜研究表明，贾巴尔泰伊斯地区的镁铁质-超镁铁质岩石包括大量的蛇纹岩，次要量的辉长岩，​​镁铁岩，混杂岩，蛇纹岩片岩和长白云母侵入。蛇纹岩构成了Jabal Tays的大部分，受到不同程度的剪切作用，通常由相对较大的蛇纹岩组成，这些蛇纹岩被蛇纹岩片岩标记的剪切带切割。基于有限应变和微观结构分析，Jabal Tays地区的镁铁质-超镁铁质岩石通常局限于脆性-韧性剪切带，它们与普遍的NW或NNW结构趋势不平行。它主要局限于变质地带，特别是由镁铁质火山岩侵入的区域。结论是，Abt片岩和准火山沉积岩之间的接触是在脆性至半延性变形条件下通过简单剪切的渐进推力过程中形成的，该剪切还涉及垂直缩短的一部分，从而在Jabal Tays地区造成了水平下的页岩化。