摘要
贵州瓮安陡山沱组磷块岩为碳酸盐岩型含磷岩系,属于浅海碳酸盐岩台地沉积区。对瓮安磷矿大塘剖面进行沉积环境研究,将Marinoan冰期后沉积的陡山沱组地层分为6个向上变浅的沉积序列。瓮安含磷岩系大部分为多旋回的叠置体,其常见的交错层理、波状层理、透镜状层理等表明了磷块岩形成于水体较浅的高能环境。南沱冰期后,陡山沱期剧烈的海侵作用引发上升洋流,携带富磷海水涌入浅水区,在海平面间歇性波动的条件下,为磷块岩的形成提供了物源与动力条件。
The phosphorites in Weng＇an,Guizhou are hosted in the lower and upper parts of the Doushantuo Formation,and made up of carbonate rock-type phosphatic rock series on a shallow marine carbonate platform.The strata of the Doushantuo Formation deposited after the Marinoan glacial period may be grouped into six shallowing-upward depositional sequences.The bulk of phosphatic rock series is built up of polycyclic stacking deposits in which cross-bedding,wavy bedding and lenticular bedding are common,implying that the phosphorites rested in the shallow marine high-energy environments.From the Nantuoan glacial period onwards,the large-scale transgressions gave rise to the upwelling oceanic currents and carried plentiful phosphatic sea water into the shallow marine areas as sites of phosphorites development.The repeated sea-level fluctuations contributed to the phosphatic source and development of polycyclic depositional sequences of the phosphorites.
出处
《沉积与特提斯地质》
CAS
CSCD
2010年第3期46-52,共7页
Sedimentary Geology and Tethyan Geology
基金
国家自然科学基金项目(批准号:40743016)
教育部"高等学校博士学科点专项科研基金"(批准号:20070616014)
中石化海相油气勘探前瞻性项目(编号:G0800-06-25-319)
贵州瓮福大信北斗山磷矿项目联合资助
关键词
贵州
瓮安
陡山沱组
磷块岩
沉积序列
Guizhou
Weng＇an
Doushantuo Formation
phosphorite
depositional sequence
作者简介
作者简介：密文天（1982-），男，博士，主要从事古生物学与地层学方面的研究
