川东南地区志留纪稀土元素分布及其地质意义  

Distribution and Geological Significance of REE in the Silurian of Southeast Sichuan

作　　者：张廷山[1,2] 陈晓慧 兰光志[1,2] 俞剑华 边立曾[1,2] 

机构地区：[1]西南石油学院勘探系 [2]南京大学

出　　处：《西南石油学院学报》1998年第3期26-30,共5页Journal of Southwest Petroleum Institute

基　　金："油气藏地质及开发工程"国家重点实验室开放研究基金

摘　　要：以川南綦江观音桥志留系剖面为代表，通过４８个样品中子活化检测出的８种稀土元素分析，详细讨论了ＲＥＥ在该剖面上的分布演化特点及表现形式；研究了本区早志留世古海洋演化及古环境特点：（１）龙马溪组为滞流浅海盆沉积；（２）从龙马溪组到石牛栏组，其ＲＥＥ逐渐减少，Ｃｅａｎｏｍ从正异常向负异常演化，海平面趋于上升，至石牛栏组达最高；（３）ＲＥＥ分析结论与用沉积学、大地构造及其它地化分析所得出的结论相吻合，证明ＲＥＥ作为环境演化的“示踪剂”有较大意义。Instrument neutron activation analyses ( INAA) were carried out on 48 Silurian samples from Guanyinqiao section in Southeast Sichuan, and 8 REEs were detected. Based on the analytic results, a detailed discussion is made on the distribution and occurrence pattern of REEs and the characteristics of Early-Silurian oceanic evolution and sedimentary environments in the area. And the following conclusion is reached: (1) the Longmaxi Formation was deposited in a shallow euxinic basin; (2) from the Longmaxi Formation to the Shiniulan Formation, ∑REE decreases gradually and Ce shifts from negative to positive anomalies, indicating a trend of rise of the sea level. The highest sea level was reached during deposition of the Shiniulan Formation. (3) the conclusions drawn from REE analyses are consistent with those from sedimentological, tectonic and other geochemical studies, indicating that REEs can be used as indicators of evolution of sedimentary environments.

关 键 词：志留纪 稀土元素分布 地球化学 油气勘探 

分 类 号：P595[天文地球—地球化学] P618.130.8[天文地球—地质学]