The oldest mid-oceanic carbonate buildup complex: Setting and lithofacies of the Vendian (Late Neoproterozoic) Baratal limestone in the Gorny Altai Mountains, Siberia
The oldest mid-oceanic carbonate buildup complex: Setting and lithofacies of the Vendian (Late Neoproterozoic) Baratal limestone in the Gorny Altai Mountains, Siberia
复制标题
DOI：
10.2183/pjab.80.422
复制
发表时间：
2004-09
期刊：
影响因子：
--
通讯作者：
Yuko Uchio;Y. Isozaki;T. Ota;Atsushi Utsunomiya;M. Buslov;S. Maruyama
中科院分区：
文献类型：
--
作者：
Yuko Uchio;Y. Isozaki;T. Ota;Atsushi Utsunomiya;M. Buslov;S. Maruyama
西伯利亚南部戈尔内阿尔泰山脉的巴拉塔石灰岩是在西伯利亚克拉通周围发育的寒武纪增生杂岩中作为大型异地岩块出现的。在寒武纪最后增生到西伯利亚之前，陆源碎屑的Baratal石灰岩直接沉积在玄武岩基底上，其地球化学特征与现代海洋高原相同。Baratal灰岩的Pb-Pb等时线年龄为598 ± 25 Ma（早Vendian期），由3种不同的相组成：1）含卵砾石和叠层石的块状灰泥岩，2）层状灰泥岩，3）以含卵砾石的灰泥岩碎屑为主的灰岩砾岩/角砾岩。第一个代表古代海洋高原顶部的浅海环境，而后两个代表高原的较深斜坡至坡底相。Vendian Baratal石灰岩提供了在大洋中部的高原/海山上重建的浅海碳酸盐堆积复合体的最古老的例子。
The Baratal limestone in the Gorny Altai Mountains, southern Siberia, occurs as large allochthonous blocks within a Cambrian accretionary complex that developed around the Siberia craton. Before the final accretion to Siberia in the Cambrian, the terrigenous clastic-free Baratal limestone was deposited directly upon a basaltic basement with a geochemical signature identical to that of modern oceanic plateau. The Baratal limestone with 598 ± 25 Ma (Early Vendian) Pb-Pb isochron age consists of three distinct facies; 1) massive lime mudstone with ooids and stromatolites, 2) bedded lime mudstone, and 3) limestone conglomerate/breccia dominated by ooid-bearing lime mudstone clasts. The first represents a shallow marine environment on top of an ancient oceanic plateau, while the latter two represent the deeper slope to bottom-of-slope facies of a plateau. The Vendian Baratal limestone provides the oldest example of a reconstructed shallow marine carbonate buildup complex developed on a plateau/seamount in a mid-ocean.