Abstract The Middle Eocene sedimentary succession in Abat Basin contains a thick mixed siliciclastic and carbonate sequence belonging to the upper member of the Musawa Formation. Over 300 m thick deltaic sediments of the Bartonian to Priabonian upper member of the Musawa Formation show two main facies successions over ten km distance, grading from a proximal delta-plain to a distal delta-front succession. Four major lithofacies associations based on their depositional significance are identified in the basin, namely the conglomerate, sandstone, mudstone, and carbonate. Each of these lithofacies associations is further divided into several individual lithofacies based on their depositional characteristics. The lithofacies association assemblage represents fluvially-dominated deltaic sediments that accumulated as a local siliciclastic feature in a carbonate dominated tropical environment. The conglomerate and sandstone lithofacies associations were deposited by channels and shoreface processes, whereas coastal processes in delta-plain setting deposited mudstone lithofacies association (including coal). The carbonate lithofacies association was deposited in an open marine shelf conditions during transgressive events associated with highstands of sea level and delta-lobe switching. The occurrence of thick siliciclastic sediments is interpreted as the result of activation of the North Ja'alan Fault resulting in a transtensional basin during the Middle to Late Eocene.

中文翻译：

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结构受限的古近系盆地中混合硅质碎屑-碳酸盐系统的沉积学：阿曼东部山脉始新世 Musawa 地层

摘要 阿巴特盆地中始新世沉积层序中含有一层厚厚的硅质碎屑和碳酸盐岩混合层序，属于Musawa组上段。Musawa 组巴托阶至普里亚博阶上段超过 300 m 厚的三角洲沉积物显示出超过 10 公里距离的两个主要相序列，从近端三角洲平原到远端三角洲前缘序列。盆地内根据沉积意义确定了四种主要岩相组合，即砾岩、砂岩、泥岩和碳酸盐岩。这些岩相组合中的每一个都根据其沉积特征进一步分为几个单独的岩相。岩相组合组合代表了以河流为主的三角洲沉积物，这些沉积物在碳酸盐为主的热带环境中积累为局部硅质碎屑特征。砾岩和砂岩岩相组合由河道和滨面过程沉积，而三角洲平原环境中的海岸过程沉积泥岩岩相组合（包括煤）。在与海平面高位和三角洲波瓣转换相关的海侵事件期间，碳酸盐岩相组合沉积在开阔的海相陆架条件下。厚硅质碎屑沉积物的出现被解释为北 Ja'alan 断层活动的结果，导致中至晚始新世期间的张张盆地。砾岩和砂岩岩相组合由河道和滨面过程沉积，而三角洲平原环境中的海岸过程沉积泥岩岩相组合（包括煤）。在与海平面高位和三角洲波瓣转换相关的海侵事件期间，碳酸盐岩相组合沉积在开阔的海相陆架条件下。厚硅质碎屑沉积物的出现被解释为北 Ja'alan 断层活动的结果，导致中至晚始新世期间的张张盆地。砾岩和砂岩岩相组合由河道和滨面过程沉积，而三角洲平原环境中的海岸过程沉积泥岩岩相组合（包括煤）。在与海平面高位和三角洲波瓣转换相关的海侵事件期间，碳酸盐岩相组合沉积在开阔的海相陆架条件下。厚硅质碎屑沉积物的出现被解释为北 Ja'alan 断层活动的结果，导致中至晚始新世期间的张张盆地。在与海平面高位和三角洲波瓣转换相关的海侵事件期间，碳酸盐岩相组合沉积在开阔的海相陆架条件下。厚硅质碎屑沉积物的出现被解释为北 Ja'alan 断层活动的结果，导致中至晚始新世期间的张张盆地。在与海平面高位和三角洲波瓣转换相关的海侵事件期间，碳酸盐岩相组合沉积在开阔的海相陆架条件下。厚硅质碎屑沉积物的出现被解释为北 Ja'alan 断层活动的结果，导致中至晚始新世期间的张张盆地。