Fossils from the Silesian-Subsilesian series of the Polish Western Carpathians: the implications for changes in sea-level and the marine environment during the Albian-Turonian

Abstract

Szydło, A., Jugowiec-Nazarkiewicz, M., Olszewska, B., 2015. Fos sils from the Silesian-Subsilesian se ries of the Pol ish West ern Carpathians: the im pli ca tions for changes in sea level and the ma rine en vi ron ment dur ing the Albian-Turonian. Geo log i cal Quar terly, 59 (1): 215-228, doi: 10.7306/gq.1206 Foraminifera and cal car e ous nannoplankton, as well as other fos sils from the Albian-Turonian de pos its of the West ern Polish Carpathians, are dis cussed in re la tion to changes in depositional en vi ron ments, which were con trolled by geotectonic activ ity, sea level changes, and anoxic and bi otic events. The dis tri bu tion and di ver sity of fos sils in the de pos its stud ied have been re lated to global sea level fluc tu a tions or lo cal sea level rise and fall. Dur ing the Albian to the Early Cenomanian, and in the Turonian, the lo cal sea level falls led to an in creased sup ply of coarse-grained ma te rial rich in si li ceous and some times cal car e ous fos sils and rock ma te rial. This cy clic pro cess has con trib uted to changes in the ma rine biota. In the Albian, monospecific foraminiferal as sem blages with a surficial infauna which col o nized bot tom wa ters af ter pe ri ods of or ganic in flux and ox y gen de fi ciency (OAE1b), evolved into more vari able as so ci a tions in clud ing deep infauna which in di cate more aer o bic con di tions. Un der these con di tions plank tonic and cal car e ous ben thic fos sils (tintinnids, cal car e ous nannoplankton, and foraminifera) were also pre served. Their pres ence was as so ci ated with the sup ply of terrigenous ma te rial from shal low-wa ter en vi ron ments and land, which were eroded dur ing re gres sions con trolled by lo cal tec tonic ac tiv ity. Dur ing the AlbianTuronian tran si tion, in tense sub si dence and vol ca nic ac tiv ity as so ci ated with a rel a tive sea level rise led to in creased produc tiv ity of phytoplankton in the area stud ied. The sea-sur face pro duc tiv ity and en hanced upwelling re sulted in ex panded short-term ox y gen min ima at the end of the Albian (OAE1d) and the Cenomanian (OAE2). In the lat ter in ter val ben thic forms be came al most ex tinct while si li ceous and cal car e ous plank ton sur vived. In the Turonian, changes in sea level and sed i mentary re gime led to re-col o ni za tion of the ba sin bot tom.

A lost carbonate platform deciphered from clasts embedded in flysch: Štramberk-type limestones, Polish Outer Carpathians

“…The deep-water Cieszyn Limestone (Cieszyn Limestone Formation, part of the Cieszyn Beds) from the western part of the Polish Outer Carpathians are well described in terms of palaeontology and in particular their stratigraphy (Szydło and Jugowiec, 1999;Olszewska, 2005;Olszewska et al, 2008) and especially sedimentologically (e.g., Nowak, 1967;Peszat, 1967;Malik, 1986;Słomka, 1986;Matyszkiewicz andSłomka, 1994, 2004). The uppermost Kimmeridgian Vendryně Formation (formerly the Lower Cieszyn Beds) -the oldest sediments ("pre-flysch") of the Polish Outer Carpathians -and the Tithonian-lowermost Valanginian Cieszyn Limestone Formation, were deposited in the deeper zones of the Proto-Silesian Basin, now forming mostly the Silesian Unit and locally the Sub-Silesian Unit (Olszewska, 2005;Olszewska et al, 2008).…”