Benthic ecosystem response to the deposition of lower Aptian black shales in an epicontinental sea

Paleoceanographic inferences from benthic foraminifera across the early Aptian Ocean Anoxic Event 1a in the western Tethys

“…Several sites show a marked decrease in abundance (or disappearance) of benthic foraminifera before the OAE 1a onset Mutterlose and Böckel 1998;Cobianchi et al, 1999;Rückheim et al, 2006;Bargen and Lehmann 2014;Moullade et al, 2015;Zorina et al, 2017;Michalík et al, 2008), which correlates with the marked decrease in abundance (BFC) identified in the Cismon Core (Fig. 9).…”

“…The comparison of the benthic foraminiferal data of the Cismon Core with benthic foraminiferal records across OAE 1a from different localities Mutterlose and Böckel 1998;Cobianchi et al, 1999;Rückheim et al, 2006;Michalík et al, 2008;Bargen and Lehmann 2014;Moullade et al, 2015;Zorina et al, 2017) shows similarities and differences as discussed below (Fig. 9).…”

“…In this regard, some indications are provided by benthic foraminifera, which are controlled by oxygen and food availability in bottom-waters (e.g., Sliter and Barker, 1972;Nyong and Olsson, 1984;van Morkhoven et al, 1986). In particular, studies on Tethyan sites (Cobianchi et al, 1999;Coccioni et 4 al., 2006;Michalík et al, 2008;Józsa et al, 2016) and sections worldwide (Elkhazri et al, 2013;Bargen and Lehmann, 2014;Zorina et al, 2017) are suggestive of a decrease in benthic foraminifera abundance before OAE 1a. Several locations show scarce or absent benthic specimens during OAE 1a, possibly, in response to a major paleoenvironmental perturbation at the seafloor (Mutterlose and Böckel, 1998;Cobianchi et al, 1999;von Bargen and Lehmann, 2014).…”

A Dufrenoyia (Ammonoidea, Deshayesitidae) fauna from Germany: Evidence for D. furcata Zone deposits at the lower–upper Aptian boundary

“…The material described here comes from a restricted southernmost extension of the LSB called the Alstätte Bay (e.g. Lehmann et al, 2012;von Bargen and Lehmann, 2014;Schlak et al, 2016; =Alstätte Embayment of Kemper, 1973b andHerngreen et al, 1994). It represents one of several small bays at the southwestern margin of the LSB (Wolburg, 1954;Schott et al, 1969).…”

“…Sediments of the Alstätte Bay were poorly exposed for many decades and thus very little research was done for many years. This changed fairly recently and a whole series of papers on the temporary EGW section in Ahaus-Alstätte that was exposed from 2009 to 2019 was published (Hoffmann and Mutterlose, 2011;Lehmann et al, 2012;Bottini and Mutterlose, 2012;Mutterlose and Bottini, 2012;von Bargen and Lehmann, 2014;von Bargen et al, 2016;Mutterlose et al, 2014;Schlak et al, 2016;Lübke and Mutterlose, 2016;Lehmann et al, 2016). However, the Ahaus area became a classic area for Aptian palaeontology in Germany already in the 19 th century due to a large number of fossiliferous, but now abandon clay pits (e.g.…”