大洋红层的分布、组成及其科学研究意义综述  

Distribution,Compositions and Significance of Oceanic Red Beds

作　　者：吕璇 刘志飞[1] 

机构地区：[1]同济大学海洋地质国家重点实验室,上海200092

出　　处：《地球科学进展》2017年第12期1307-1318,共12页Advances in Earth Science

基　　金：国家自然科学基金重点项目"南海中央海盆中新世以来深水沉积作用及其区域构造与环境演化意义"(编号:41530964);国家自然科学基金重大研究计划集成项目"南海深海沉积过程与机制"(编号:91528304)资助~~

摘　　要：大洋红层作为一种特殊的海相沉积,代表了典型的富氧沉积环境,具有重要的科学研究价值。从大洋红层发现以来已开展大量的研究,但研究主要集中在白垩纪大洋红层,对整个大洋红层的特征及其科学研究意义的认识还不够全面。因此,在回顾大洋红层研究进展的基础上,总结其全球性的空间分布特征,对矿物和元素组成进行对比,发现主要矿物组分和元素组成与大洋红层的致色并无直接关系,而主要受到区域环境和物源来源的影响。大洋红层的致红是由铁氧化物或者含锰方解石控制,主要有2种成因机制:(1)因氧化条件而形成致色矿物;(2)因低沉积速率而形成致色矿物。因此,大洋红层所具有的独特成因机制和全球分布特征,使其对指示古沉积环境特征、重建古洋流发育、推测古气候变化具有重要的科学研究意义。在已有研究进展的基础上,提出未来展望,以期从多元化方向对全球大洋红层开展深入的研究。Oceanic red beds are widely distributed in the global oceans and across the entire Phanerozoic period, which mostly appeared after oceanic anoxic events. They represent typical oxygen-rich sedimentary environment and play a significant role on ocean science research. Numerous studies have been carried out since the oceanic red beds were discovered. However, previous studies mainly focused on the Cretaceous oceanic red beds, and the understanding of the characteristics and scientific significance of oceanic red beds are not comprehensive. Therefore, we here summarized the global distribution characteristics and compared mineral and element compositions of various lithological oceanic red beds, including marly, clayey and cherty oceanic red beds. The main mineral and element components of oceanic red beds have no direct relationship with the color of the sediments, and mainly are affected by the regional environment and provenances. Therefore, the mineralogical and geochemical characteristics of oceanic red beds should be analyzed in combination with the regional background. The red coloration of oceanic red beds is controlled mainly by hematite, goethite and manganese-bearing calcite, which have two main mechanisms： （1） Colored minerals formed in oxic conditions; （2） Colored minerals formed due to low deposition rates. These two mechanisms are not completely independent, but complement one another with either dominance in most oceanic red beds. Lithological characteristics of oceanic red beds are controlled by three factors, including water depth, productivity and nutrients. Therefore, the formation of oceanic red beds should be considered with global changes and regional events. The unique origin mechanism and global distribution characteristics of long time-scale oceanic red beds can be used to indicate sedimentary paleoenvironment, paleo-oceanic current, and paleoclimate change. In addition, hydrothermal or magmatic activities on the ocean floor could also produce red-color deposits that are strongly

关 键 词：大洋红层 全球分布 成因机制 古海洋 古气候 

分 类 号：P736.2[天文地球—海洋地质]