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The structural position and tectonosedimentary evolution of the Polish Outer Carpathians

100%

Oszczypko N.

tom Vol. 52, nr 8/2

780-791

The sedimentary basins of the Outer Carpathians are regarded as the remnant oceanic basins that were transformed into the foreland basin. These basins developed between the colliding European continent and the intra-oceanic arcs. In the pre-orogenic and syn-orogenic evolution of the Carpathian basins the following prominent periods can be established: Middle Jurassic — Early Cretaceous opening of basins and post-rift subsidence, Late Cretaceous—Palaeocene inversion, Palaeocene toMiddle Eocene subsidence, Late Eocene–Early Miocene synorogenic closing of the basins. In the Outer Carpathian sedimentary area the important driving forces of the tectonic subsidence were syn- and post-rift thermal processes as well as the emplacement of the nappe loads related to the subduction processes. Similar to the other orogenic belts, the Outer Carpathians were progressively folded towards the continental margin. This process was initiated at the end of the Palaeocene at the Pieniny Klippen Belt Magura Basin boundary and completed during Early Burdigalian in the northern part of the Krosno flysch basin.

Jurassic syn-rift and Cretaceous syn-orogenic, coarse-grained deposits related to opening and closure of the Vahic (South Penninic) Ocean in the Western Carpathians – an overview

100%

Plasienka D.

2012

tom Vol. 56, No. 4

601--628

Although no undoubted oceanic crustal rock complexes of Penninic affinity participate in the present surface structure of the Western Carpathians, indirect lines of evidence suggest prolongation of the South Penninic-Vahic oceanic tract into the ancient Carpathians. The sedimentary record of both the syn-rift and syn-orogenic clastic deposits reveal their origin between the outer Tatric (Austroalpine) and the inner Oravic (Middle Penninic) margins. The rifting regime is exemplified by the normal fault-related scarp breccias of the Jurassic Borinka Unit in the Male Karpaty Mts., which are characterized by local, gradually denuded source areas. Two other regions provide examples of a contractional regime, both related to shortening and closure of the Vahic oceanic domain. The Belice Unit in the Povazsky Inovec Mts. includes Upper Jurassic-Lower Cretaceous eupelagic, mostly siliceous deposits and a thickening-upwards Senonian sequence of turbiditic sandstones, conglomerates and chaotic breccias. It is inferred that this succession represents the sedimentary cover of oceanic crust approaching a trench, its incorporation in the accretionary complex and finally underthrusting below the outer Tatric margin. In the Oravic units of the Pieniny Klippen Belt, deep-marine conglomerate/breccia bodies with olistoliths indicate collision-related thrust stacking that started from the Maastrichtian (Gregorianka Breccia of the Sub-Pieniny Unit) and terminated with the Lower Eocene Milpos Breccia in the Saris Unit. In addition, a tentative recycling scheme of “exotic” clastic material from mid-Cretaceous conglomerates of the Klape Unit to various Klippen Belt units is outlined. This material is considered to be unrelated to the Vahic oceanic realm and its closure, and likely represents erosional products of more distant orogenic zones.

Sinemurian to lowermost Toarcian ammonites of the Brescian Prealps (Southern Alps, Italy): preliminary biostratigraphical framework and correlations

84%

Meister C. , Schirolli P. , Dommergues J.-L.

tom Vol. 7, no. 1

9-18

A set of 28 ammonite biohorizons or faunal assemblages is proposed for the Sinemurian, the Pliensbachian and the lowermost Toarcian of the Brescian Prealps, in part based on the published data of the authors of this contribution and partly on new results, derived both from recent field investigations and from the study of the historical collection of Lower Jurassic ammonites preserved in the Museum of Natural Sciences of Brescia (Northern Italy). The biohorizons are present in the Liassic carbonate succession of the Brescian Prealps, cropping out between the eastern surroundings of Brescia (Botticino), to the east, and Lake Iseo, to the west. Since the Hettangian this region was subjected to Jurassic rifting. The area of study was located on the eastern border of the wide Lombardian Basin, a part of the southern continental passive margin of Tethys. An articulated fault-system, trending from Brescia to the North, separated the western subsiding area of the Val Trompia-Sebino Basin from the eastern Botticino structural high. After the drowning of the Rhetian-Hettangian Corna Platform, the very thick synrift succession of the Medolo Group accumulated in the Val Trompia-Sebino Basin, whereas the coeval reduced sequence of the Rezzato Encrinite and the overlying Botticino Corso Rosso covered the Botticino High, subsequent to the Early Sinemurian. The ammonite biohorizons and assemblages recognised are quite well integrated and correlable with either the NW European standard zonation or the different zonations proposed for the Tethyan Realm.

Genesis and evolution of Sudetic late Hercynian volcanic rocks inferred from trace element modelling

84%

Dziedzic K.

tom Vol. 31, nr 1

79-91

The late Hercynian volcanic complexes in the Sudetes originated due to decompressional melting of the subcontinental lithospheric source region. The volcanic activity started with the calc-alkaline andesite magma in an Early Permian, followed by the picritic relicts and the andesitic assemblage rocks both of tholeiitic affinity. The tholeiitic andesites originated by AFC processes involving mantle-and lower crust-derived material. The differentiation of the andesitic parental magma within high-level magma chamber(s) by AFC processes involving upper crust components yielded the acid volcanic varieties in the area. The geodynamic processes and geological relations correspond with those of continental rift zones.