Gravitational collapse structures are commonly observed in shelf-margin deltas underlain by mobile shales. However, these structures are rarely accompanied by mud diapirs. This paper presents an updated study of the gravity-driven system in the West Luconia Deltas, a shelf-margin delta system, in the Kangxi Depression, southern South China Sea. Compared to the classical shale-detachment model, the syn-collapse deformation in the contractional domain in this study is accommodated mainly by thrust faults combined with mud diapirs rather than simply imbricated thrusts. Based on seismic interpretation and structural analysis, this gravity-driven system is divided into three domains, the extensional domain, the contractional domain and the transitional domain. All of these domains are intruded by mud diapirs. The quantitative analysis of the amounts of extension and contraction suggests that these structures mainly resulted from gravitational collapse rather than the tectonic compression. Quantification of the relative contributions of gravity spreading and gliding indicates that the gravitational collapse was mainly driven by gravity spreading. Two episodes of collapse are suggested by the analysis of the progradation of the West Luconia Deltas and the features of the syn-collapse structures. The first episode was minor and not accompanied by diapirism, whereas the second episode was major and accompanied by diapirism. The entire evolution of the GDS is divided into five stages: (1) the first episode of the gravitational collapse, lasted from the earliest Middle Miocene to the earliest Pliocene; (2) the deposition of an interval between the syn-collapse strata and the mobile shale, occurred in the Early Pliocene.; (3) the initiation of the second episode of the gravitational collapse, lasted from the Early Pliocene to the Late Pliocene; (4) the attenuation and basinward migration of the gravity-driven deformation, lasted from the Late Pliocene to the Early Pleistocene; and (5) the ending of the gravitational collapse, lasted from the Early Pleistocene to the present. The last four stages were accompanied by intensive diapirs which pierced the overlying strata and became targets for the hydrocarbon exploration.

中文翻译：

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南海南部康熙De陷西Luconia三角洲不断升级控制下，重力驱动系统伴随二叠纪的演化

重力塌陷结构通常在活动页岩下的陆缘三角洲中观察到。但是，这些结构很少伴有泥浆底泥。本文介绍了对南海南部康熙De陷西部陆架三角洲系统西卢卡尼亚三角洲重力驱动系统的最新研究。与经典的页岩-分离模型相比，本研究中收缩域的顺塌陷变形主要是由与泥质底泥结合的逆冲断层而不是单纯的盘状逆冲来解决的。在地震解释和结构分析的基础上，该重力驱动系统分为三个域，即拉伸域，收缩域和过渡域。所有这些领域都受到泥浆底泥的侵入。对伸缩量的定量分析表明，这些结构主要是由于重力塌陷而不是构造压缩所致。量化重力扩展和滑动的相对贡献表明，重力坍塌主要由重力扩展驱动。通过分析西卢卡尼亚三角洲的演化和同崩塌结构的特征，提出了两次坍塌事件。第一集是次要的，不伴有精神分裂症，而第二集是主要的，并伴有精神分裂症。GDS的整个演变过程分为五个阶段：（1）重力塌陷的第一阶段，持续时间从最早的中新世到最早的上新世；（2）在上新世早期发生了塌陷层与活动页岩之间的间隔沉积。（3）第二次重力塌陷的发生，从上新世晚期到上新世晚期；（4）重力驱动的变形从上新世晚期到更新世的衰减和向盆地的迁移；（5）重力崩溃的结束，从早更新世一直持续到现在。最后四个阶段伴随着密集的底盘，这些底盘刺穿了上覆地层，成为油气勘探的目标。（4）重力驱动的变形从上新世晚期到更新世的衰减和向盆地的迁移；（5）重力崩溃的结束，从早更新世一直持续到现在。最后四个阶段伴随着密集的底盘，这些底盘刺穿了上覆地层，成为油气勘探的目标。（4）重力驱动的变形从上新世晚期到更新世的衰减和向盆地的迁移；（5）重力崩溃的结束，从早更新世一直持续到现在。最后四个阶段伴随着密集的底盘，这些底盘刺穿了上覆地层，成为油气勘探的目标。