Magneto-, and isotope stratigraphy around the Jurassic/Cretaceous boundary in the Vysoká Unit (Malé Karpaty Mountains, Slovakia): correlations and tectonic implications

Abstract

Magneto-and isotope stratigraphic studies in the Vysoká Nappe (Hlboča section, Fatric Unit, Malé Karpaty Mts, Slovakia) were performed. A generally decreasing δ 13 C isotope curve is interpreted as a primary trend from the Late Oxfordian (3.3 ‰ V-PDB) to the Late Tithonian (1.8-1.4 ‰ V-PDB). Data from the Tithonian part of the Tegernsee Formation probably reflect "local" basin processes connected with the breccia formation in the latest Tithonian/earliest Berriasian and/or with possible diagenetic overprint. The C-isotope record of the Berriasian Padlá Voda Formation is more homogeneous (1.4-1.8 ‰ V-PDB) and assumed to be primary. Magnetostratigraphic investigations were focused on the Jurassic/Cretaceous (J/K) boundary strata. Upper Tithonian nodular limestones of the Tegernsee Formation differ substantially from Lower Berriasian calpionellid limestones of the Padlá Voda Formation in rock magnetic properties. Hematite is present in the Tegernsee Formation, while magnetite is the only magnetic mineral of the Padlá Voda Formation. Additionally, the latter formation contains superparamagnetic magnetite, which significantly influences its magnetic susceptibility. Correlation of normal and reversed magnetic intervals with the Late Tithonian global polarity time scale was supported by microfossil stratigraphy. M21n to M20n magnetozones were distinguished, including the short reversed Kysuca (M20n1r) Subzone within M20n. Interpretation of Lower Berriasian magnetostratigraphy was more complex due to presence of breccia horizons and a stratigraphic gap at the J/K boundary in the lower part of the Padlá Voda Formation embracing M19r and most of M19n magnetozones. This formation was also partially affected by remagnetization. Detailed correlation between the isotope-and magnetic stratigraphy of the Tithonian-Berriasian interval between Hlboča and Brodno sections is also complex due to J/K stratigraphical gap within the Hlboča section. The primary B component accounts for counter-clockwise rotation of the Vysoká Unit with a magnitude of ca. 50°. Since the paleodeclination of Paleogene and Karpatian-Eggenburgian rocks in the area is similar, the rotation must have taken place after Early Miocene. The paleoinclinations of several Upper Tithonian-Berriasian sections of the Central Western Carpathians and western part of the Pieniny Klippen Belt are consistent and indicate paleolatitude of 27-30°N.

Carbon cycle history through the Jurassic–Cretaceous boundary: A new global δ13C stack

“…Increasingly negative δ 18 O values are often correlated with elevated temperatures in environmental settings where continental ice volume is at a minimum and evaporation or freshwater inputs are minor factors. Similar trends have been observed elsewhere (e.g., Tremolada et al, 2006;Price and Rogov, 2009;Grabowski et al, 2010b), but not universally as other studies found opposite trends (e.g., Emmanuel and Renard, 1993;Padden et al, 2002). Larger datasets through the Late Jurassic and into the Cretaceous, based on the isotopic composition of fossil belemnites and brachiopods (e.g., Veizer, et al, 1999;Gröcke et al, 2003;Wierzbowski, 2004;McArthur et al, 2007;Riboulleau et al, 1998;Bodin et al, 2009Bodin et al, , 2015Price and Rogov 2009;Dera et al, 2011;Alberti et al, 2012;Price et al, 2000;2013;Meissner et al, 2015), also show a similar trends (Fig.…”

Structural pattern and emplacement mechanisms of the Krížna cover nappe (Central Western Carpathians)

“…Pre-or syn-thrusting paleomagnetic data from the Krížna Nappe were reported by Kruczyk et al (1992), Grabowski (1995Grabowski ( , 2000 and Grabowski et al (2009Grabowski et al ( , 2010. These data show a systematic variation from the west (Malé Karpaty Mts) to the east (Tatra Mts) -the western localities show Cretaceous paleodeclinations rotated counterclockwise (CCW) up to 70°, further east in the Strážovské vrchy and Malá Fatra Mts this CCW rotation decreases to 60-25°, in the Nízke Tatry Mts it is only 20°, then no rotation was detected in the Chočské vrchy and Western Tatra Mts, while the easternmost sites in the Eastern Tatra Mts and the Ružbachy "island" have already shown a clockwise (CW) rotation 20-50°.…”

“…This fanwise arrangement of paleomagnetic declinations remains preserved also after subtracting the Late Tertiary CCW rotation of the whole Western Carpathian orogenic system by some 80° ( Grabowski & Nemčok 1999;Márton et al 1999;Grabowski 2010). Although particular directions might have been affected also by local tectonic phenomena, such as the vertical axis block rotation within wrench fault zones, or slight relative rotations of individual "core mountains" (Hrouda et al 2002), the fanwise pattern of paleomagnetic directions might be interpreted in terms of oroclinal bending (Kruczyk et al 1992;Grabowski 2010). Since the paleodeclinations are also subparallel to the presumed transport directions of the Krížna Nappe deduced from the kinematic criteria (Prokešová 1994;Kováč & Bendík 2002;Plašienka 2003), it is highly probable that they are also roughly parallel to the translation pathways of the Krížna Nappe System.…”

“…These data show a systematic variation from the west (Malé Karpaty Mts) to the east (Tatra Mts) -the western localities show Cretaceous paleodeclinations rotated counterclockwise (CCW) up to 70°, further east in the Strážovské vrchy and Malá Fatra Mts this CCW rotation decreases to 60-25°, in the Nízke Tatry Mts it is only 20°, then no rotation was detected in the Chočské vrchy and Western Tatra Mts, while the easternmost sites in the Eastern Tatra Mts and the Ružbachy "island" have already shown a clockwise (CW) rotation 20-50°. This fanwise arrangement of paleomagnetic declinations remains preserved also after subtracting the Late Tertiary CCW rotation of the whole Western Carpathian orogenic system by some 80° ( Grabowski & Nemčok 1999;Márton et al 1999;Grabowski 2010). Although particular directions might have been affected also by local tectonic phenomena, such as the vertical axis block rotation within wrench fault zones, or slight relative rotations of individual "core mountains" (Hrouda et al 2002), the fanwise pattern of paleomagnetic directions might be interpreted in terms of oroclinal bending (Kruczyk et al 1992;Grabowski 2010).…”

Integrated biostratigraphy and carbon isotope stratigraphy of the Upper Jurassic shallow water carbonates of the High-Tatric Unit (Mały Giewont area, Western Tatra Mountains, Poland)

“…The three sec tors in the Up per Kimmeridgian-Lower Tithonian in ter val of the d 13 C curve might be iden ti fied also in the Hlboèa sec tion (Grabowski et al, 2010). Biostratigraphic cor re la tion of the sec tors fits quite well to the Ma³y Giewont and D³uga Val ley sec tions (Fig.…”