Integrated Rhaetian foraminiferal and conodont biostratigraphy from the Slovenian Basin, eastern Southern Alps
Integrated Rhaetian foraminiferal and conodont biostratigraphy from the Slovenian Basin, eastern Southern Alps
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DOI：
10.1007/s00015-012-0117-1
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发表时间：
2012-10-01
影响因子：
3.1
通讯作者：
Rozic, Bostjan
中科院分区：
文献类型：
--
作者：
Gale, Luka;Kolar-Jurkovsek, Tea;Rozic, Bostjan
牙形刺和再沉积的浅水底栖有孔虫共同出现在斯洛文尼亚盆地（南阿尔卑斯山）的上诺里安-雷蒂亚斯拉特尼克地层中。对科布拉山和斯拉尼克山剖面进行了研究，以便首次给出这两组之间的直接相关性。诺里安-雷蒂亚边界 (NRB) 位于牙形刺 Misikella posthernsteini 的首次出现基准处，并接近有孔虫 Involutina turgida 的首次出现。 Trocholina turris 与 duostominids 的关联是雷蒂亚人的一个很好的标志。结合我们的数据对文献进行仔细修订，最终重新确定了几种有孔虫物种的地层范围。有孔虫三叠纪-侏罗纪边界 (TJB) 可以用 Galeanella tollmanni、“Sigmoilina” schaeferae 或 duostominids 的最后出现来定义。最上部的Rhaetian Misikella ultima 牙形刺带的缺失以及有孔虫和牙形刺TJB 的高度重合可能表明在Slatnik 地层的上部存在hiati。因此，无法观察到晚三叠世有孔虫在边界处消失的确切模式。然而，很明显，珊瑚礁栖息的有孔虫、双口有孔虫和大多数平台栖息的有孔虫的有孔虫群落遭到大量破坏。 TJB 的生物变化最好解释为生物钙化危机的结果。
Conodonts and re-deposited shallow-water benthic foraminifera co-occur in the Upper Norian-Rhaetian Slatnik Formation of the Slovenian Basin (Southern Alps). The Mt. Kobla and Mt. Slatnik sections were investigated in order to give the first direct correlation between these two groups. The Norian-Rhaetian boundary (NRB) is placed at the First Appearance Datum of the conodont Misikella posthernsteini and is approached with the First Occurrence of the foraminifer Involutina turgida. An association of Trocholina turris with duostominids is a good marker for the Rhaetian. Careful revision of literature combined with our data culminated in reambulation of stratigraphical ranges for several foraminiferal species. The foraminiferal Triassic-Jurassic boundary (TJB) can be defined with the Last Occurrence of Galeanella tollmanni, "Sigmoilina" schaeferae or duostominids. The absence of the uppermost Rhaetian Misikella ultima conodont zone and the close coincidence of foraminiferal and conodont TJB could point to the presence of hiati in the upper part of the Slatnik Formation. Consequently, the exact pattern of disappearance of Late Triassic foraminifera at the boundary could not be observed. It is clear, however, that the foraminiferal assemblage was decimated for reef-dwelling foraminifera, duostominids and most of the platform-dwelling foraminifera. Biotic changes at the TJB are best explained as a result of a biocalcification crisis.