During the Late Jurassic-Early Cretaceous, a significant gas-bearing siliciclastic succession was deposited in the Kopeh Dagh fold-thrust belt in northeastern Iran. Study of the regional evolution of depositional system and geodynamic setting of the red beds continental strata can help in a better understanding of the development of an intracontinental extension in this part of the Eurasia Plate. However, this evolution is driven by faulting events that are not fully understood. Facies analysis in wells and outcrops of the Upper Jurassic-Lower Cretaceous Mozduran and Shurijeh formations in the Saleh Abad area, the easternmost part of the Kopeh Dagh Basin, led to the identification of two fluvial braided river systems in the Shurijeh Formation. Provenance and sedimentological studies indicate that siliciclastic sediments were supplied from the south into the north during the Late Jurassic-Early Cretaceous in the Kopeh Dagh Basin. The higher compositional and textural maturity in the upper part of the Shurijeh Formation relative to the lower part indicate more recycling and more extensive transport of the sediments. Two stages of normal faulting can be identified based on the tectonostratigraphic evolution in this interval: The first phase was initiated with polymictic conglomerates during the Late Jurassic in the lower part of the Shurijeh Formation, while the basin-controlling fault was a buried structure. The second phase started with an influx of quartz conglomerates when the basin-controlling fault reached the surface in the middle part of the Shurijeh Formation. This study integrates new field observations and interpretations to enhance understanding of a complex history of multiphase deformation controlled facies patterns, structural geometries of the Late Jurassic-Early Cretaceous. Renewed Cretaceous extension generated accommodation space for the transgressive Shurijeh Formation.

中文翻译：

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伊朗科佩达格褶皱冲断带东部上侏罗统-下白垩统硅质碎屑岩（Shurijeh 组）的构造地层

晚侏罗世-早白垩世期间，伊朗东北部的Kopeh Dagh 褶皱逆冲带沉积了重要的含气硅质碎屑岩序列。研究红层陆相地层沉积体系的区域演化和地球动力学背景，有助于更好地了解欧亚板块陆内伸展的发育过程。然而，这种演变是由尚未完全了解的断层事件驱动的。对 Kopeh Dagh 盆地最东部的 Saleh Abad 地区上侏罗统-下白垩统 Mozduran 和 Shurijeh 地层的井和露头进行的相分析，确定了 Shurijeh 地层中的两个河流辫状河系统。物源和沉积学研究表明，科佩达格盆地晚侏罗世-早白垩世期间，硅质碎屑沉积物从南部供应到北部。相对于下部，Shurijeh 组上部的成分和结构成熟度较高，表明沉积物有更多的回收和更广泛的运输。根据该层段的构造地层演化，可以识别出两个阶段的正断层：第一阶段始于晚侏罗世Shurijeh组下部的多混砾岩，控盆断裂为隐伏构造。第二阶段始于控盆断层到达 Shurijeh 组中部地表时石英砾岩的涌入。这项研究整合了新的现场观测和解释，以增强对晚侏罗世-早白垩世多相变形控制相模式、构造几何的复杂历史的理解。更新的白垩纪伸展为海侵的 Shurijeh 地层创造了容纳空间。