新疆桑株剖面二叠系克孜里奇曼组生物礁基本特征  

Reef Pattern of the Permian Keziliqiman Formation in Pishan of Xinjiang

作　　者：王翼君 王振宇[1] 唐洪明[1] 杨光 张云峰[1] 屈海洲[1] WANG YiJun;WANG ZhenYu;TANG HongMing;YANG Guang;ZHANG YunFeng;QU HaiZhou(School of Earth Science and Technology,Southwest Petroleum University,Chengdu 610500,China)

机构地区：[1]西南石油大学地球科学与技术学院,成都610500

出　　处：《沉积学报》2024年第1期171-186,共16页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(41702122)。

摘　　要：[目的]塔西南地区二叠系可见具有良好勘探前景的生物礁。[方法]通过新疆皮山县桑株剖面二叠系克孜里奇曼组生物礁的野外露头观察和薄片研究,详细梳理了该礁体的基本特征。[结果]克孜里奇曼组生物礁属于沿台地边缘生长的点礁,礁体发育完整的礁基、礁核、礁前、礁后、礁盖亚相。其中,礁核靠近礁前的岩性主要为珊瑚骨架岩,礁核靠近礁后低能带的岩性主要为海绵障积岩。礁体的形成受控于海平面的升降,它是在塔西南地区海平面上升的背景下逐步形成,后期又随着塔西南地区海平面的快速下降,桑株地区变为气候炎热干燥的潮上带,藻类开始繁盛,白云岩化加剧,造礁生物大量死亡,礁体消亡。桑株生物礁的古生物特征和地球化学特征表明,塔西南此次海平面下降可能和早二叠世的冰期有关。此后,克孜里奇曼组生物礁开始遭受成岩作用的改造。[结论]总体上看,克孜里奇曼组生物礁受成岩改造的影响较小,而且成岩过程主要受沉积期海相流体的影响,非海相流体的影响相对较小,且非海相流体主要影响生物碎屑,对泥晶基质基本没有影响。[Objective]The Permian strata in the southwestern Tarim Basin include an organic reef with good explo-ration prospects.[Methods]Based on outcrop observations and thin section examination of the Permian Keziliqiman Formation reef in the Sangzhu profile of Pishan county,Xinjiang,this study explores the basic reef characteristics.[Results]The Keziliqiman reef is a point reef that grew along the platform margin and consists of a base,core,front,back,and cap sub-facies.The lithology of the reef core close to the high-energy front is primarily coral skeleton rock,and that of the reef core close to the low-energy back is primarily sponge barrier rock.The development of the reef was subject to the rise and fall of sea level;it emerged when the sea level rose in the southwestern Tarim Basin and disappeared when the sea level fell rapidly.Rhe fall of the sea level reduced the Sangzhu area to a hot and dry su-pratidal zone where algae began to flourish,dolomitization intensified,and then reef building organisms died en masse.Paleontological and geochemical characteristics of the reef indicate that the sea-level fall in the southwesterb Tarim Basin was likely related to the Early Permian glaciation.When there were no more building organisms,the Keziliqiman reef was transformed by diagenesis.[Conclusions]Overall,the impact of diagenetic transformation was rather small,and its diagenetic process had reliant more on marine fluids in its sedimentary period than on nonmarine fluids,for non-marine fluids were powerful enough to affect biodetritus but powerless against the argillaceous matrix.

关 键 词：二叠系 生物礁 造礁生物 成岩作用 海平面 

分 类 号：P588.245[天文地球—岩石学]