The paleoenvironment of an early Middle Miocene Paratethys sequence in NE Austria with special emphasis on paleoecology of mollusks and foraminifera

详细信息    查看全文

• 作者：Mandic ; Oleg ; Harzhauser ; Mathias ; Spezzaferri ; Silvia ; Zuschin ; Martin
• 关键词：Paleoecology ; Foraminifera ; Mollusca ; Central Paratethys ; Middle Miocene ; Early Badenian
• 刊名：Geobios
• 出版年：2002
• 出版时间：December, 2002
• 年：2002
• 卷：35
• 期：Supplement 1
• 页码：193-206
• 全文大小：1.19 M

文摘

In a multidisciplinary approach including data on paleoecology of foraminifera, mollusks, balanids and coralline algae, as well as on taphonomy, sedimentology, sequence stratigraphy and regional geology, the environmental reconstruction for the Niederleis Basin (a satellite depression of the Vienna Basin and important fossiliferous site of the Central Paratethys region) is provided. The data came from two sections in proximal (section Buschberg) and distal (section Bahnhof) position relative to the northwesterly exposed basement chain. The accomplished analysis confirmed the presumed bathymetric and paleogeographic differences. A paleodepth of about 100 m for the Buschberg- and up to 500 m for the Bahnhof-section was indicated by foraminifera. Due to the short distance of the Buschberg-section to the paleoshore, a drowned paleocliff paralleling the tectonic margin of the Niederleis Basin is assumed. Synsedimentary tectonic sagging of the basin is inferred for the sequence at Bahnhof. Whereas the fossil record from autochthonous sediments implies deepening upward, the mixed fossil assemblage from tempestites implies shallowing of the supply center, respective gradual installation of extended onshore to lagoonal habitats. This is in accordance with the inferred biostratigraphic position within the late Lower Lagenidae Zone characterized by the installation of the high stand system tract in the Vienna Basin.