Where Was the Magura Ocean?
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DE DE GRUYTER Acta Geologica Polonica, Vol. 65 (2015), No. 3, pp. 319–344 OPEN DOI: 10.1515/agp-2015-0014 G Where was the Magura Ocean? NESTOR OSZCZYPKO1, ANDRZEJ ŚLĄCZKA1, MARTA OSZCZYPKO-CLOWES1 and BARBARA OLSZEWSKA2 1Jagiellonian University, Institute of Geological Sciences, Oleandry 2a, 30-063 Kraków, Poland; 2Polish Geological Institute, Carpathian Branch, Skrzatów 1, 31-560 Kraków, Poland; [email protected]; [email protected], [email protected] ABSTRACT: Oszczypko, N., Ślączka, A., Oszczypko-Clowes, A. and Olszewska, B. 2015. Where was the Magura Ocean. Acta Geologica Polonica, 65 (3), 319–344. Warszawa. In the Late Jurassic to Early Cretaceous palaeogeography of the Alpine Tethys the term Ocean is used for dif- ferent parts of these sedimentary areas: eg. Ligurian – Piedmont and Penninic, Magura, Pieniny, Valais and Ceahlau-Severins oceans. The Magura Ocean occupied the more northern position in the Alpine-Carpathian arc. During the Late Cretaceous–Paleogene tectono-sedimentary evolution the Magura Ocean was transformed into several (Magura, Dukla, Silesian, sub-Silesian and Skole) basins and intrabasinal source area ridges now in- corporated into the Outer Western Carpathians. Key words: Cenozoic, Outer Western Carpathians; Palaeogeography; Intrabasinal ridges; Basin development. INTRODUCTION time, terms such as the Magura Basin, Magura Nappe or the Magura Superunit are commonly used. Some- The term Magura Ocean, understood as the east- times, the Magura Ocean and the Magura Basin are ern prolongation of the Ligurian – Piedmont and Pen- used interchangeably, causing confusion of their con- ninic Ocean (eg. Puglisi 2009; 2014), is often used in cepts. Whereas the terms Magura Basin and Magura the palaeogeographic and palaeotectonic reconstruc- Nappe are sufficiently well-defined, the spatial and tions of the Outer Western Carpathians (Channell and temporal coverage of the Magura Ocean has not been Kozur 1997). More often the Magura Ocean is con- defined in more detail. sidered as the eastern extension of the Valais Ocean / The southern margin of the Magura Ocean is des- North Pennic domain (Schmid et al. 2004; Sand- ignated as the northern boundary of the Pieniny Klip- ulescu 2009; Ustaszewski et al. 2008; Schmid et al. pen Belt (PKB), which separates the Central Western 2008), although the presence of the Valais Ocean is Carpathians (CWC, Cretaceous accretionary wedge) also debatable (see Schmid et al. 2004). The concept from the Outer Western Carpathias (OWC, Paleo- of the Magura Ocean is usually used in reference to gene-Early Miocene accretionary wedge). The PKB is the Late Jurassic and Early Cretaceous (Birkenmajer a 650 km long suture zone, but only a few kilometres 1986), but it is also used for the Late Cretaceous and wide (Text-figs 1A, B). Within the PKB, the northern even for the Paleogene (Frontzheim et al. 2008; edge of the CWC belonged to the Czorsztyn Unit Plašienka 2014; Kovač et al. in press). At the same (Ridge), while the Grajcarek Unit represented the 320 NESTOR OSZCZYPKO ET AL. 18°E 51°N 24°E P O L A N D 100 km 51°N B Kraków ry Kraków A emian promoto Ostrawa Przemyśl Boh Wien Fig 5 ALCAPA 30°E 47°N Tisza Dacia C Z E C H R E P. Brno Fig 6 Ivanofrankivsk Bucuresti U K R A I N EDubrovnik Moesian promotory Sofia S L O V A K I A 42°N 42°N Fig 7 Kosice 18°E 30°E Uzhhorod H U N G A R Y Fig 8a Bratislava 0 20 40 60 80 100km Fig 8b R O M A N I A Botizii LEGEND B Rakhiv Carpathian foreland Rakhiv Unit LEGEND A undeformed European foreland Miocene molasse Marmarosh Crystalline Massif Miocene Thrust belt Folded Miocene molasse & Magura group of nappes Borislav- Pokuttya Unit external foredeep Skole/Skyba Unit Pieniny Klippen Belt and Marmarosh klippens ophiolites, suture zones & oceanic accretionary prisms South Apuseni-Transylvanian oceanic units Subsilesian- Zdanice units Tatricum and its sedimentary cover & East Vardar ophiolites Veporicum, Zemplinicum, Hronicum, Adria derived thrust sheets: Southern Alps and Silesian- Chornohora Unit Dinaridic continenetal margin including Bukk Mountains Gemericum, Meliaticum, Turnaicum & Silicicum Adria derived allochtons Austoalpine and Dukla Unit Inner Carpathian and Buda Palaeogene ALCAPA Mega Unit Tisza Mega Unit, including the North Porkulets Unit Neogene Alpine volcanics Apuseni Mountains (NA) Dacia Mega Unit, including Biharia nappe system of the Apuseni Mountains (Bi) Text-fig. 1. A – Tectonic sketch-map of the Alpine–Carpathian-Pannonian area (after Schmid et al. 2008); B – Tectonic sketch-map of the Western Carpathians and adja- cent Ukrainian Carpathians with location of lithostratigraphic logs of the Magura Nappe in Poland, Western Slovakia and Czech Republik (based on Oszczypko et al. 2005b) southern, transitional (to the PKB basin), margin of The lower part of the Grajcarek succession (Text- the Magura Basin (Ocean). The aim of this study is to fig. 4) is represented by manganiferous as well as red discuss what the Magura Ocean was and its location and green radiolarites, as known from the Szczawnica in space and time. As a benchmark, we chose the sections (Sikora 1971a, b). In these radiolarites, Nowak Małe Pieniny Mts in the Polish Outer Carpathians, (1971) recognized two microfossil assemblages: (1) an where the transition zone between the Magura and older one, with Nannoconus ex gr. steinmanni Kampt- PKB basins (Birkenmajer 1977, 1986) was first well- ner (late Tithonian) without lower Tithonian documented. In the study, we used our observations stomiosphaerids and calpionellids; and (2) a younger from the Outer Carpathians, from the Rhenodanu- one (?Valanginian–Hauterivian), with Nannoconus bian Flysch Zone, as well as our recent results from div. sp. and Cadosina aff. olzae Nowak. Birkenmajer the studies of the PKB. (1977, 1979, 2001) included the radiolarites into the Sokolica and Czajakowa formations (Bathonian–Ox- fordian), followed by (very condensed) red Aptychus GRAJCAREK UNIT OF THE MAŁE PIENINY MTS Marls of the Czorsztyn Formation (Kimmeridgian– (POLAND) Tithonian), cherty limestones of the Pieniny Formation (Tithonian–Barremian), spotty marls of the Kapuśnica The Małe Pieniny Mts of the Polish Western Formation, and black marly shales of the Wronine Carpathians are located between the Dunajec River Val- Formation (Aptian–Cenomanian). Our recent studies ley to the west and the Polish/Slovak state boundary to (Oszczypko et al. 2012a; Oszczypko and Oszczypko- the east (Text-fig. 2). In this area, the PKB is composed Clowes 2014, and references therein), based on (from north to south) of the Grajcarek Unit and the foraminifers, documented that the Szczawnica-Za- Czorsztyn, Niedzica-Czertezik, Branisko and Pieniny baniszcze Upper Jurassic–Lower Cretaceous con- klippen units of the PKB (Text-fig. 3). The Jurassic– densed deposits are overlain by the black flysch of the Lower Cretaceous klippen units have a common mid- Szlachtowa Formation (Aptian–Albian). Completely Upper Cretaceous sedimentary cover (Birkenmajer different opinions are represented by Birkenmajer et al. 1970, 1977, 1986). (2008, and reference therein) and Gedl (2013, and ref- 321 WHERE WAS THE MAGURA OCEAN? erences therein) who consider the Szlachtowa Forma- longing to the Opaleniec Formation of Albian–Ceno- tion as of Toarcian–Bajocian age. manian age (Oszczypko et al. 2004, 2012a). The total thickness of the Szlachtowa Formation is Between the Opaleniec and Malinowa formations, up to 220 m (Birkenmajer 1977; Birkenmajer at al. Oszczypko et al. (2012a) recognized red and green ra- 2008), but in the PD-9 borehole, in Szczawnica (Birken- diolarites followed by spotty limestones and marls majer et al. 1979), the partial thickness of the “Black with rare Late Albian calcdinocysts (Colomisphaera Flysch” was about 310 m (120 m and 190 m of the aff. pokornyi Řehánek, Oszczypko et al. in prepara- Szlachtowa and Bryjarka formations, respectively). The tion) with intercalations of black and green shales fol- Szlachtowa Formation is composed of turbiditic sand- lowed by 1 m thick red and green shales (Bonarelli stones with intercalations of black and dark grey marly Horizon, Uchman et al. 2013). These strata, 3–10 m mudstones and shales. It is overlain by 10 to 16 m thick thick, were previously described by Sikora (1962, packets of light grey spotty shales and marls with pyrite 1971a, b) as the “Cenomanian Key Horizon” (CKH) concretions and sideritic limestone intercalations be- (Text-fig. 4). 461000 UTM 34U 465000 469000 473000 5480000 UTM 34U 5467000 Szczawnica B ESKID SĄDECKI PD9 Dunajec Szlachtowa Grajcarek Czarna Woda oda Creek ary Creek Rogacz St elski Czarna W Si Jaworki Biała Wo Lesnica Woda olnia d Szt a Biała ? 5471000 Haligovce LOVAKIALitmanova Velky Lipnik S LOVAKIA L UBOVNIANASKA? S V RCHOVINA 0123 km S PISKA MAGURA Jarabina MAGURA NAPPE SUB-PIENINY (CZORSZTYN) NAPPE Paleogene of the Krynica Zone Czorsztyn succesion Kremna and Zlatne formations (Oligo-Miocene) Niedzica and Czertezik succession PIENINY NAPPE sl Neogene andesites PIENINY KLIPPEN BELT Branisko and Pieniny successions GRAJCAREK THRUST-SHEETS Upper Cretaceous and Paleogene of Myjava Zone Jurassic to Early Cretaceous "Black flysch” Haligovce klippen Malinowa Formation (Cenomanian - Campanian) thrust faults Jarmuta Formation (Maastrichtian - Peleocene) borehole ?Proč - Jarmuta formation (Paleocene - Eocene) CENTRAL CARPATHIAN PALEOGENE Text-fig. 2. Geological sketch-map of the Małe Pieniny Mts and Lubovnianska Vrchovina Range with location of lithostratigraphic logs (based on Oszczypko et al. 2010 and Oszczypko and Oszczypko-Clowes 2014) 322 NESTOR OSZCZYPKO ET AL. In Małe Pieniny, except for the Upper Jurassic/ 1977, 1979; Birkenmajer and Pazdrowa 1968) as tectonic Lower Cretaceous radiolarites and limestones of the Szcza- blocks of Jurassic radiolarites, and of Tithonian– wnica section, there are several sections with radiolarites Barremian cherty limestone of the Pieniny Limestone type, and cherty limestones without clear stratigraphical position. derived from the Branisko Unit of the PKB. Our studies The majority of them have been interpreted (Birkenmajer document that part of these small klippens belongs to the Text-fig.