Early Senonian radiolarian microfauna and biostratigraphy from the Western Vardar Zone (Western Serbia)

Abstract

Abstract:The studied deposits represent the sedimentary cover of ophiolitic mélange of the Western Vardar Zone Belt. An association of sediments that correspond to a primary pyroclastic material occurs in the Upper Cretaceous carbonate sediments near the village of Struganik (Western Serbia). This is an interlayer within mainly carbonate sediments represented by limestone, clayey limestone and marlstone. It is made of the following succession: a lamina made of crystalline quartz, sanidine, plagioclase and biotite and a layer of clay. The clay is of the smectite type, highly crystalline. The age of the radiolarian assemblage from the clay layer is assigned to Early Senonian, based on the co-occurrence of radiolarian taxa: Dictyomitra formosa Squinabol, Dictyomitra koslovae Foreman, Dictyomitra torquata Foreman, Alievium sp. cf. A. superbum (Squinabol) and Pseudoaulophacus sp. cf. P. venadoensis Pessagno. The pyroclastic material was brought into the water environment by a cloud that was formed after an explosive eruption whose exact location cannot be determined at the moment. According to geological data, there are no indications of volcanic activity before the Late Cretaceous in the wider studied area. Marine sedimentation continued after gravitational differentiation of pyroclastic material. The results of petrological and sedimentological investigations reveal that Struganik Limestone originated in a deep-water environment and that the sedimentation area was on the continental slope.

Deciphering the geodynamic evolution of the Dinaric orogen through the study of the ‘overstepping’ Cretaceous successions

“…The phases of tectonically induced regressions are interpreted after the comparison between the stratigraphy of the Cretaceous successions in the Dinarides and the global eustatic curve (Haq, 2014) and relative sea level oscillations recorded in the Tithonian to Cenomanian shallow-water carbonates of the AdCP (Husinec & Jelaska, 2006). New stratigraphic and age data presented in this work integrate the following literature: Adriatic carbonatic platform (Dinara Mountain section) after Vlahović et al (2005 with references); Vranduk and Ugar formations after Mikes et al (2008 with references); Pogari Group after Blanchet et al (1970), Blanchet (1975) and Hrvatović (2006); Mokra Gora Group after (Ba-Struganik area) Vishnevskaya et al (2009), Djerić et al (2009) and Bragina et al (2014) (Mokra Gora area) Pejović & Radoičić (1971), Olujić et al (1987), Radoičić & Schlagintweit (2007) and Banjac et al (2007); Guča Group and Ljig-Brus-Kosovska-Mitrovica flysch afterćirić (1958), Dimitrijević & Dimitrijević (1987), Radoičić et al (2010), Zelic et al (2010) and Chiari et al (2011). Chronostratigraphic chart after Cohen et al (2013).…”

“…The succession evolves upwards into more open-marine deposits (outer-ramp to basinal environment) with sedimentation of platy limestones alternating with marlstones and fine-grained calcarenites of Turonian age (Filipović et al 1978). Finally, the succession passes into a basinal flysch consisting of low-density turbidite deposits (calcareous sandstones and calcirudites) and cherty limestones of Coniacian-Santonian age (Djerić et al 2009;Vishnevskaya et al 2009;Bragina et al 2014). Towards the Santonian portion of the succession, slumping layers and other syn-sedimentary deformations became common (Fig.…”

Mesozoic basins on the Adriatic continental margin – a cross-section through the Dinarides in Montenegro / Mezozojski bazeni na kontinentalnem robu Jadranske plošče – presek čez Dinaride v Črni gori

“…The mid-Cretaceous transgression marked by the onset of marine sedimentation is slightly diachronous along the Dinarides-Hellenides and varies from the early Aptian to the late Albian (Nirta et al 2020 with references). The Upper Cretaceous part of the succession is in places entirely of deepwater origin and is composed of calcareous turbidites and cherty limestone, which yielded Santonian to early Campanian radiolarians (Djerić et al 2009;Bragina et al 2014Bragina et al , 2018Bragina et al , 2020Đerić & Gerzina 2014).…”

Petrophysical and mechanical properties of the Struganik limestone (Vardar zone, Western Serbia)

“…A recent micropaleontological analysis, i.e., the association of pelagic globotruncanas, indicates that these sediments are of Campanian age (GAJIĆ 2007). The age of radiolarians from the layer of smectite clay within the micrite limestone of the Struganik was defined as the Coniacian (VASIĆ et al 2005;DJERIĆ et al 2009).…”

“…Many authors investigated the stratigraphy of this area (e.g., ANĐELKOVIĆ 1978), paleontological assemblages (e.g., FILIPOVIĆ et al 1978) and tectonic features (KARAMATA et al 1994(KARAMATA et al , 2000DIMITRIJEVIĆ 2001;GERZINA 2002;ROBERTSON et al 2009). Only a small number of recently published papers provide general information on the stratigraphy and lithology of stone in the Struganik area (VASIĆ et al 2001;RABRENOVIĆ et al 2002;VASIĆ et al 2005;GAJIĆ 2007;DJERIĆ et al 2009;GAJIĆ & VASIĆ 2011). Unfortunately, petrological and technical features of the Struganik limestone, data of the depositional processes and problems of the quality and assortment of use have not yet been studied in detail.…”