CAJ | 학술논문

结合野外露头剖面观察与深入剖析，对宣汉盘龙洞长兴组生物礁沉积特征和成礁模式进行了室内综合分析。该礁位于鄂西城口海槽西侧台缘带，为相对海平面整体下降背景下形成的一套加积进积型台地边缘生物礁。该露头出露良好，长兴组以海绵骨架礁灰岩和海绵骨架礁白云岩为主。综合岩性、古生物等沉积相标志，该区长兴组属于碳酸盐岩台地边缘沉积体系，可进一步划分出斜坡相、台地边缘生物礁和台地边缘生屑滩相，其中台地边缘生物礁又可划分为礁基、礁核、礁盖、礁前、礁后等亚相。区域沉积环境、岩性、古生物以及生物礁的内部构成分析认为，盘龙洞生物礁可分为3期成礁旋回：第一旋回礁是低能环境下形成的未经充分生长而被淹死的礁，主要由生屑泥晶灰岩和少量骨架岩组成；第二旋回礁形成于较高能环境下，经历了充分生长后暴露而死亡，暴露时间短，仅顶部发生了较弱的白云岩化；第三旋回礁则形成于高能环境下，经历了充分生长并暴露出海平面后死亡，其死亡后经波浪和水流的改造作用而形成生屑滩，长期暴露发生强烈白云岩化。
결합야외로두부면관찰여심입부석，대선한반룡동장흥조생물초침적특정화성초모식진행료실내종합분석。해초위우악서성구해조서측태연대，위상대해평면정체하강배경하형성적일투가적진적형태지변연생물초。해로두출로량호，장흥조이해면골가초회암화해면골가초백운암위주。종합암성、고생물등침적상표지，해구장흥조속우탄산염암태지변연침적체계，가진일보화분출사파상、태지변연생물초화태지변연생설탄상，기중태지변연생물초우가화분위초기、초핵、초개、초전、초후등아상。구역침적배경、암성、고생물이급생물초적내부구성분석인위，반룡동생물초가분위3기성초선회：제일선회초시저능배경하형성적미경충분생장이피엄사적초，주요유생설니정회암화소량골가암조성；제이선회초형성우교고능배경하，경력료충분생장후폭로이사망，폭로시간단，부정부발생료교약적백운암화；제삼선회초칙형성우고능배경하，경력료충분생장병폭로출해평면후사망，기사망후경파랑화수류적개조작용이형성생설탄，장기폭로발생강렬백운암화。
reef ,and platform marginal bio‐clast bank .The platform marginal reef facies can be divided into reef base ,reef core , reef cap ,fore reef ,and back reef . Panlongdong reef consists of three depositional cycles : the first cycle of reef was formed in a low energy environment which was drown without sufficient grow th ;the second cycle of reef was formed in a relative high energy environment which died of exposure after experiencing sufficient grow th with weak dolomitization on the top ;and the third cycle of reef was formed in a high energy environment which died of exposure after experiencing sufficient grow th ,and then the reef formed a bio‐clast bank ,and later was destroyed by waves and tides .The reef and bio‐clast bank experienced an intensive dolomitization after a long‐term exposure .