中文摘要：

川东北元坝地区飞仙关组具有良好的勘探开发前景。利用铸体薄片、普通薄片、能谱扫描电镜和电子探针等技术手段，研究飞仙关组碳酸盐岩岩石特征及成岩作用。研究表明飞仙关组发育的灰岩可以划分为微晶灰岩、藻灰岩和颗粒灰岩，其中微晶灰岩和颗粒灰岩又分别细分为5个小类和4个小类；白云岩包括微晶白云岩、膏化微晶白云岩和粪球粒微晶白云岩，但以微晶白云岩为主。飞仙关组成岩作用主要有泥晶化、压实-压溶、胶结、重结晶、交代、白云石化、溶蚀、充填和破裂等作用，其中胶结作用可分为3期，溶蚀作用也可分为3期。建立了重要储层段飞二段的成岩序列，结果表明成岩作用中充填作用最强，胶结作用和压实-压溶作用次之，泥晶化、溶蚀、重结晶及破裂作用较弱，白云石化作用最弱。胶结作用和充填作用是飞二段储集性变差的主要原因，但倘若局部地区受到较强的建设性成岩作用改造，如热液白云石化、破裂作用等，就易形成较好的储集空间。

英文摘要：

There is a good exploration and development prospect in Feixianguan Formation of the Yuanba block in Northeast Sichuan.This paper analyzes the types and diagenesis of the Lower Triassic Feixianguan Formation carbonate rock by using cast thin section,normal thin section,SEM and EMP.The research shows that the limestone of Feixianguan Formation can be divided into microcrystalline limestone,algal packstone and grainstone.The microcrystalline limestone can be again subdivided into 5 classes and the grain limestone 4 classes.The dolomite is composed of microcrystalline dolomite, gypsum microcrystalline dolomite and faecal pellet microcrystalline dolomite,but mainly microcrystalline dolomite.The diagenesis of Feixianguan Formation includes micritization, compaction-pressure solution, cementation, metasomatism, recrystallization, dolomitization,dissolution,filling and fracturing.Both cementation and dissolution can be divided into three periods.Finally,the building of the diagenetic sequence of Member 2 of Feixianguan Formation indicates that the filling is the strongest among diagenesis,and it is followed by the cementation and compaction-pressure solution.The micritization,and dissolution,recrystallization and rupture have weak effects.The dolomitization is the weakest.The cementation and packing action are the main reason which makes the reservoir property of Member 2 of Feixianguan Formation poor. But it would be easy to form better reservoir spaces if the area were strongly reconstructed by diagenesis like hydrothermal dolomitization and cataclasis.