Contributions to the lithostratotype of "Hofergrabenmergel" (Hochmoos Formation, Lower Gosau Subgroup; Coniacian/; Upper Austria)

Lenka Hradecká1, Harald Lobitzer2, Franz Ottner3, Felix Schlagintweit4, Marcela Svobodová5,István Szente* Lilian Švábenická1 & Irene Zorn6

1 Czech Geological Survey, Klárov 3, CZ-118 21 Praha 1, Czech Republic. [email protected]; [email protected] 2 Lindaustrasse 3, A-4820 Bad Ischl, Austria. [email protected] 3 Bilateral cooperation between Universität für Bodenkultur, Institut für Angewandte Geologie, Peter Jordan Strasse 70, A-1190 Wien, Austria. [email protected] Geologische Bundesanstalt Vienna 4 Lerchenauerstrasse 167, D-80935 München, Deutschland. [email protected] and 5 Institute of Geology, v.v.i., Academy of Sciences of the Czech Republic, Rozvojová 269 , CZ-165 00 Praha 6, Czech Republic. [email protected] Czech Geological Survey Prague 6 Geologische Bundesanstalt, Neulinggasse 38, A-1030 Wien, Austria. [email protected] *Museum of Natural History, Faculty of Science, Eötvös University, Pázmány P. sétány 1/c, H-1117 Budapest, Hungary. [email protected]

L i m e s t o n e i n t e r c a l a t i o n s The “Hofergrabenmergel” on their classical According to the present knowledge this The ostracod fauna from the Hofergraben is locality in Sattelgraben (currently used In the upper part of the grey predominantly shallow-marine macrofossil-rich very poor. Main faunal elements are Bairdia -bearing marl sequence Zw 1 topographic name for „Hofergraben“) and marly sequence in the Hofergraben is up to and Cytherella. The palynomorph assemblage SCH2 o f t h e H o f e r g r a b e n m e r g e l SCH6 Zw 2 SCH3 SCH1 outcrops in Finstergraben and Schattau in several tens of meters thick and comprises corresponds to Oculopollis-Complexiopollis several layers of limestones in SCH3A SCH7 K+S 7 K+S 11 FG 1,2 Gosau region, Northern Calcareous Alps, nannozones UC11 and UC12 correlated with the Dominance Zone (Coniacian-Santonian). the dm-range are intercalated. Upper Austria, represent the upper section of Upper Coniacian-Middle Santonian. Dinocyst assemblages suggest prevailingly Yellow coquinas, respectively the Hochmoos Formation, which is part of the Nannofossil assemblages consist of scarce shallow marine conditions (Dinogymnium, limestones rich in fossil debris, consisting of corals, pelecypods Lower Gosau Subgroup. Micula staurophora, and consistent Odontochitina, Xenascus), occasionally mixed HG2 HG1 and gastropods predominate, HG3 The Hofergabenmergel (name coined by Lucianorhabdus quadrifidus with long distal with chorate dinocysts of litoral or neritic also non-limestone clasts can Kollmann, in Plöchinger 1982) are represented stems. The foraminiferal assemblages are environment (Spiniferites, Florentinia). be observed in part frequently by soft grey marls in part rich in corals, dominated by benthonic taxa and confirm a Another type of the intercalations gastropods and bivalves. stratigraphical range from the Dicarinella consists of slightly bituminous concavata to Dicarinella asymetrica Zones. black marly limestones, which are also rich in . Also fine-clastic/sandy limestone beds Finstergrabenwandl Finstergrabenr Hofergraben occur. In all these intercalations also microfossils, which indicate a l a g o o n a l s h a l l o w w a t e r palaeoenvironment can be observed . Schattau 3A

Following the heavy rainfalls in early August We consider the Hofergrabenmergel basically 2002 a shallow ditch along the Zwieselalm forest as sediments of a shallow marine muddy water road temporarily exposed the topmost grey environment. In the upper part of the coral marls of Hochmoos Formation (sample point marls sequence light-yellowish limestone beds, K&S 11 A) below the Kalksandsteinbank of rich in corals, gastropods and bivalves are Finstergrabenwandl outcrop. The rich intercalated and also