High-resolution foraminiferal biostratigraphy across the Moscovian/Kasimovian boundary

在本研究中，我在乌克兰顿涅茨克盆地的Kalinovo剖面和中国扬子地台的中底剖面研究了跨越莫斯科-卡西莫维奇边界的高分辨率有孔虫生物地层学。在Kalinovo剖面，研究了覆盖莫斯科-卡西莫维奇边界间隔的以下12种石灰岩：N_2、N_3、N_3^1、N_3^2、N_3^3、N_5^1、O_1、O_1^1、O_1^2、O_2、O_3和O_4。在N_2中发现了Taitzehoella和Fusulina等典型的晚莫斯科时代的镰孢属，在N_3中发现了拟镰孢属和原始的原镰孢属，表明其时代为晚莫斯科时代。N_3^3记录了类似于P. pseudomontiparus和/或P. subschwagerinoides的原粒虫的出现，并且可能已经是传统的早期卡西莫维奇。O_1区主要为似钝尾鳄和拟镰尾鳄，并有稀有的原始蒙蒂帕拉斯。这一水平可能与传统的中期卡西莫维奇的早期部分有关。典型的蒙地帕罗斯富含O_2， ...更多信息 是属于传统的卡西莫维奇中间派的因此，在卡利诺沃剖面中，卡西莫瓦阶的传统基底可以位于N_3-N_3^3层段内的某个地方。在Donets，Idiognathodus sagittalis是Kasimovian基底的一个潜在的标志牙形石种，最早出现在O_1。在中底剖面的最新莫斯科-卡希莫瓦期，建立了5个镰刀菌带，从上到下依次为Fusulinella-Fusulina带、Protriticites sp. A带、Protriticites sp. B带、Montiparus带和Triticites带。其中，Protriticites sp. A带记录了原始Protriticites的出现，其螺旋鞘中带有细穿孔。相比之下，在Protriticites sp. B带发现了具有与原始角质层相当的明显粗糙穿孔的高级Protriticites。这些证据表明，中底剖面的Kasimovian基底几乎与Protriticites sp. A带和Protriticites sp. B带的界线重合。少

In the present research, I studied high-resolution foraminiferal biostratigraphy across the Moscovian/Kasimovian boundary in the Kalinovo section of the Donets Basin, Ukraine, and the Zhongdi section of the Yangtze Platform, China.In the Kalinovo section, the following 12 limestones covering a Moscovian-Kasimovian boundary interval are examined : N_2, N_3, N_3^1, N_3^2, N_3^3, N_5^1, O_1, O_1^1, O_1^2, O_2, O_3, and O_4. In N_2, typical late Moscovian fusuline genera such as Taitzehoella and Fusulina are found. N_3 yields Quasifusulinoides and primitive Protritivcites, suggesting a latest Moscovian age. N_3^3 records the occurrence of Protriticites similar to P. pseudomontiparus and/or P. subschwagerinoides, and is probably already of traditional, early Kasimovian. O_1 is dominated by Obsoletes and Quasifusulinoides, together with rare, primitive Montiparus. This level is possibly correlated to the early part of the traditional, middle Kasimovian. O_2 is rich in typical Montiparus, and … More is assignable to the traditional, middle Kasimovian. In the Kalinovo section, therefore, the traditional base of the Kasimovian can be placed somewhere within the N_3-N_3^3 interval. In Donets, ldiognathodus sagittalis, a current potential marker conodont species for the base of the Kasimovian, occurs first in O_1. Thus, this level is several depositional cycles higher than the traditional base of the Kasimovian.In the latest Moscovian-Kasimovian of the Zhongdi section, five fusuline zones were established: in ascending order, they are the Fusulinella-Fusulina, Protriticites sp. A, Protriticites sp. B, Montiparus, and Triticites Zones. Of them, the Protriticites sp. A Zone records the occurrence of primitive Protriticites that bears fine perforations in its spirotheca. In contrast, advanced Protriticites with definitely coarse perforations comparable with rudimentary keriotheca are found in the Protriticites sp. B Zone. These lines of evidence suggest that the base of the Kasimovian in the Zhongdi section almost coincides with the boundary between the Protriticites sp. A Zone and Protriticites sp. B Zone. Less