作为海相沉积的特殊类型,显生宙海相红层是一个符合开展地球系统科学研究的、穿越地球圈层的研究对象,具有重要的研究潜力和价值。本文对除白垩纪之外的显生宙海相红层的分布进行了初步的整理和归纳。据初步统计,红色灰岩出现12套,红色泥质岩有6套,分布于显生宙的不同时代。在此基础上,系统介绍了海相红层的四种成因机制,包括红色灰岩的两种成因机制:(1)自生致色铁氧化物形成于沉积时.的氧化条件;(2)自生致色铁氧化物形成于沉积时的铁细菌媒化作用;红色泥质岩的两种成因机制:(3)致色铁氧化物来源于陆地风化;(4)自生致色铁氧化物形成于低沉积速率条件。
The Phanerozoic marine red bed, a special type of marine deposit, is of great research potential for earth system sciences studies. This paper compiled temporal and spatial distribution of marine red beds in the Pbanerozoic on the basis of the published data and field investigation in China. There are at least 12 suits of red limestones and 6 suits of red shales distributed in nearly every period from the Cambrian to the Quaternary. Based on these data, four origins of marine red bed were summarized, including two origins for red limestone: (1) iron oxidation in high- ly oxic environment, similar to that of the Cretaceous oceanic red beds (CORBs), (2) iron-bacterial mediation at the time of sedimentation; and two origins for red shale, (3) detrital origin of the iron oxides derived from conti- nental weathering, (4) iron oxides formed in oligotrophic conditions with low sedimentation rate.