Agglutinated foraminifera from the Northern Tarcău Nappe (Eastern Carpathians, Romania)

Abstract

Abstract. The Tarcău Nappe is the most important unit of the Carpathian flysch due to its size, stratigraphic and tectonic complexity. Our purpose was to identify the major types of foraminifera assemblages in relation to the paleoenvironmental settings and their biostratigraphic potential. The identified assemblages are characteristic to the Cretaceous and Paleogene, consisting mostly of benthic agglutinated and, in lower proportions, benthic calcareous and planktonic species. Local abundances of Glomospira allowed the correlation of the examined strata to the early Eocene "Glomospira event" described from the Carpathians in Poland, Morocco, and Labrador. Rzehakina fissistomata (Grzybowski) identified at Palma makes possible the correlation of these deposits to the Paleocene Rzehakina fissistomata Zone. Paleoenvironmental conditions (depth, amount of oxygen, nutrients) could be inferred based on specific assemblages and compared to the already described types of facies from the Carpathians.

Glomospira Acme During the Paleocene-Eocene Thermal Maximum: Response to CaCO3 Dissolution or to Ecological Forces?

“…High percentages of these taxa have also been documented from other Tethyan sections (Outer Carpathians, and the Austrian Untersberg and Anthering sections, ,50-60% of the assemblages) and from the northeast Atlantic Ocean (Iberian Plain, Zumaia and Trabakua sections, ,12-55% of the assemblages). A middle bathyal-abyssal depth has been suggested for all these localities during the earliest Eocene (Morgiel and Olszewska, 1981;Kuhnt and Collins, 1996;Egger andothers, 2003, 2005;Bąk, 2004;Galeotti and others, 2004;Alegret andothers, 2009a, b, 2010;Giusberti and others, 2009;Bindiu and Filipescu, 2011).…”

“…Apart from the paleobathymetry, the paleoenvironmental reconstruction during the earliest Eocene notably differs from site to site: well-oxygenated bottom waters have been inferred for some of these sections (Alegret andothers, 2009 a, b, 2010;Giusberti and others, 2009), while low-oxygen conditions have been suggested for Anthering, Austria (Egger and others, 2003), Dukla Nappe in the Polish Outer Carpathians (Bąk, 2004), and possibly Straja, Romania (Bindiu and Filipescu, 2011). Similarly, primary productivity in surface waters and trophic conditions at the seafloor increased at some localities (Romanian and Polish Carpathians, and Austrian sections) and decreased or did not change significantly at others (e.g., Spanish and Italian sections) (Table 1).…”

“…Repmanina charoides (usually reported as Glomospira) is common in well-oxygenated environments , as well as in modern hydrocarbon-seep environments (Kaminski, 1988), and it has been reported from early Eocene locations with varying degrees of oxygenation (Egger and others, 2003;Bąk, 2004;Galeotti and others, 2004;Alegret andothers, 2009a, b, 2010;Giusberti and others, 2009;Bindiu and Filipescu, 2011; Table 1). The main feature of benthic foraminiferal assemblages during oceanic anoxic events (OAEs) is a dramatic decrease in diversity and abundance, or even a total absence, although some studies record short-term repopulation events throughout OAEs (Friedrich, 2010).…”

Foraminiferal biostratigraphy and paleoenvironments of the middle Eocene deposits from the northern part of the Tarcău Nappe (Eastern Carpathians, Romania)

“…Jones and Charnock (1985) showed that the general morphology of the foraminiferal test is related to the preferred ecological niches, therefore foraminifera can be divided into morphotypes. Their scheme has been modified and applied in palaecological studies by further authors (Nagy et al, 1995;Bąk et al, 1997;Peryt et al, 1997Peryt et al, , 2004Van der Akker et al, 2000, Szydło, 2004, 2005Lemańska, 2005;Reolid et al, 2008;Kender et al, 2009;Cetean et al, 2011;Murray et al, 2011;Setoyama et al, 2011;Bindiu and Filipescu, 2011;Bindiu et al, 2013, Setoyama et al, 2013.…”

Biostratigraphy and paleoenvironment of the Upper Cretaceous deposits in the northern Tarcău Nappe (Eastern Carpathians) based on foraminifera and calcareous nannoplankton

“…During the last decades, the Upper Cretaceous deposits of the Eastern Carpathian flysch in Romania were micropaleontologically studied by Neagu (1970Neagu ( , 1990, Neagu et al (1992), Ion et al (1995), Melinte & Bubík (2005), Melinte et al (2007), Bojar et al (2009), Bindiu & Filipescu (2011), and Cetean et al (2011). The Late Santonian to Late Campanian interval was reported as a period of major sea-level fluctuations in the Tethyan area (Lüning et al 1998;Li et al 2000;Cetean et al 2011) and therefore it offers a high potential for identification of stratigraphic events.…”