塔里木盆地西北缘克孜勒布拉克南沟乌拉尔统巴立克立克组生物礁地质特征  

Geological characteristics of Cisuralian Series Baliklik Formation reefs at Kezilblak Nangou in the northwest margin of the Tarim basin

作　　者：王翼君 杨光 王振宇[2] 唐洪明[2] 张云峰[2] 屈海洲[2] WANG Yijun;YANG Guang;WANG Zhenyu;TANG Hongming;ZHANG Yunfeng;QU Haizhou(Chengdu Technological University,Chengdu,Sichuan 611730,China;School of Earth Science and Technology,Southwest Petroleum University Chengdu,Sichuan 610500,China)

机构地区：[1]成都工业学院,四川成都611730 [2]西南石油大学地球科学与技术学院,四川成都610500

出　　处：《地质学报》2024年第4期1037-1055,共19页Acta Geologica Sinica

基　　金：国家自然科学基金项目(编号41702163,41702122)资助的成果。

摘　　要：塔里木盆地西北缘二叠系巴立克立克组广泛发育具有油气勘探意义的巨厚台地边缘生物礁,本文对塔西北克孜勒布拉克南沟出露的典型的二叠系巴立克立克组生物礁进行了详细的宏微观研究。该套生物礁以生屑滩为礁基,礁核下部主要为蓝绿藻建造的各类微生物岩,其结构组分主要为凝块及破碎的微凝块,次为叠层石,此时的水体能量较低;礁核上部局部发育叶状藻礁,并伴生大量的海生底栖动物,此时礁体开始暴露在浪基面之上,大量发育角砾状灰岩,并遭受大气淡水岩溶的改造。除了台缘带外,塔西北柯坪地区同期的局限台地中也发育小规模的、具微生物岩特征的台内礁滩体,说明该时期区域上的环境条件普遍适宜造礁。巴立克立克组的该套礁滩体的形成时间为乌拉尔世阿瑟尔期晚期—萨克马尔期,这与乌拉尔世塔里木大火成岩省早期阶段相当,因此,推测该套礁滩体的形成和当时的火山活动产生的火山灰导致南天山洋残余海盆的海水“富营养化”有关。藻类的爆发使得巴立克立克组礁滩体的δ^(13)C值较之康克林组的碳酸盐岩呈现显著正偏移。但是,巴立克立克组的礁滩体受胶结作用等建设性成岩作用的改造程度较深,利于“成岩”,不利“成储”,使得区域上巴立克立克组的礁滩体尽管相带较好,但储渗性极差,唯有受构造裂缝改造部分可发育高渗层。因此,可以确定:塔西北乌拉尔世巴立克立克组的礁滩储层基本不受相控,主要发育裂缝型储层。因此,今后对于塔西北二叠系礁滩油气藏的勘探应重点关注构造裂缝发育段。本研究对今后塔西北巴立克立克组生物礁优质储层预测提供了科学依据,对于我国乃至世界范围内二叠系微生物岩的研究也有一定助益。At the Permian Baliklik Formation in the northwest margin of the Tarim basin,there developed massively thick reef limestone that bears oil and gas exploration significance.This paper makes macro and micro examinations of the reefs which cropped out at Kizilbulak Nangou in the northwest margin of the Tarim basin.This set of reefs had bioclastic shoals as reef bases.The lower zone of the reef core is mainly composed of microbialite of various types formed by Cyanobacteria,with thrombolite and broken-up microclots as its most dominant structural components,followed by stromatolites.At this time,the hydraulic energy is low.In the upper zone of the reef core locally developed phylloid algal reefs,with a large quantity of marine benthic fauna among them.At this time,the reef body began to expose itself above the wave base,with a large number of brecciated limestone developed,and it was subjected to the transformation of atmospheric freshwater karstification.In addition to the platform margin zone,the synchronous restricted platform in the Keping area in the northwest Tarim basin also developed small-scale intra-platform reef-shoal complexes,with microbial rock characteristics,indicating that the environmental conditions in the region during this period were generally favorable for reef building.The set of reef-shoal complexes in the Baliklik Formation formed in the Late Atherian period of the Cisuralian to the Sa kmarian age,contemporary with the early stage of large igneous provinces of Cisuralian Tarim basin.Therefore,it is speculated that the forming of this set of reef-shoal complexes was related to the“eutrophication”of the sea water in the residual basin of the south Tianshan ocean;the“eutrophication”had been caused by the volcanic ash spurted out by volcanic activities at that time.As a result of the outbreak of algae,the δ^(13)C value of the reef-shoal complexes in the Baliklik Formation shows a significant positive shift compared with that of the carbonate rocks in the Kangkelin Formation.However,the

关 键 词：塔西北 乌拉尔世 微生物岩 成岩作用 储层物性 

分 类 号：P618.13[天文地球—矿床学]