The Manín Unit represents a transitional tectonic element between the Central Western Carpathians and the Pieniny Klippen Belt. The overall map-view structure of the Manín Unit is dominated by elliptical antiforms composed of comparatively competent Jurassic and Lower Cretaceous strata, surrounded by soft Upper Cretaceous shales, marls and sandstones. During layer-parallel shortening, the Manín sedimentary succession behaved as a multilayer reinforced by a variously thick rigid layer of massive Urgonian limestone. The multilayer deformed by flexural slip folding, but the fold wavelength was controlled by the rigid layer undergoing buckling. It is inferred that, besides the lateral thickness differences in the rigid layer, development of brachyfolds and particularly periclines such as the Butkov fold also resulted from the interference of two perpendicular macroscopic fold systems.
The Cr-Ni-rich micas, Ni-Co sulphide phases and associated minerals occur in a small body of listvenite, an extensively altered serpentinite, in Lower Palaeozoic paragneisses near Muránska Zdychava village in Slovenské Rudohorie Mts. (Veporic Superunit, central Slovakia). The main rock-forming minerals of the listvenite are magnesite, dolomite and a serpentine-group mineral, less frequently calcite, quartz and talc. Accessory minerals of the listvenite include Cr-Ni--rich micas, chromite, and Ni-Co-Fe-(Cu-Pb) sulphide minerals (pyrite, pyrrhotite, pentlandite, millerite, polydymite, violarite, siegenite, gersdorffite, cobaltite, chalcopyrite and galena). The micas from the Muránska Zdychava listvenite (Cr-Ni-rich illite to muscovite and Ni-dominant trioctahedral mica) contain the highest Ni concentrations ever reported in the mica-group minerals (up to 22.8 wt. % NiO or 1.46 apfu Ni). The Cr concentrations are also relatively high (up to 11.0 wt. % Cr 2 O 3 or 0.64 apfu). contents, the latter two typical of ultrabasic rocks. The more advanced alteration stage shows lower SiO 2 , but higher content of volatiles (c. 35 wt. % of LOI) bound in carbonates and hydrated silicate minerals. Based on geochemical and mineralogical characteristics, the studied listvenite body originated during three principal evolutionary stages: (1) peridotite stage, (2) serpentinization stage, and (3) hydrothermal-metasomatic stage (listvenitization). The listvenite origin was probably connected with Alpine (Late Cretaceous) late-orogenic uplift of the Veporic Superunit crystalline basement and retrograde metamorphism; we assume P-T conditions of the final listvenite stage at ~200 MPa and up to 350 °C. The NE-SW and NW-SE trending fault structures played a key role during the process of listvenitization as they channelized the CO 2 -rich fluids that transformed the serpentinized peridotite into the carbonate-quartz listvenite.
1 Matej Bel Uni ver sity, De part ment of Ge og ra phy and Ge ol ogy, Fac ulty of Nat u ral Sci ences, Tajovského This study aims at quan ti ta tive ki ne matic anal y sis of fault-slip data and palaeostress re con struc tion of polyphase brit tle struc tures de vel oped in the Manín Unit crop ping out in the Mid dle Váh River Val ley of west ern Slovakia. The Manín Unit neigh bours the Pieniny Klippen Belt that fol lows the bound ary be tween the Paleogene accretionary wedge of the Outer Carpathians and the Cre ta ceous nappe sys tem of the Cen tral West ern Carpathians. Af ter the nappe em place ment dur ing mid-Cre ta ceous times, the Manín Unit was in cor po rated into the Pieniny Klippen Belt and at tained its com plex tec tonic style. Based on ki ne matic anal y sis of meso-scale faults with slick en sides, six (D 1 -D 6 ) brit tle de for ma tion stages have been discerned. The rel a tive suc ces sion of in di vid ual palaeostress states was de rived from field struc tural re la tion ships; their stratigraphic age was es ti mated pri mar ily by com par i son with other pub lished data. Palaeostress anal y sis in the Manín Unit re vealed the ex is tence of six dif fer ent palaeostress fields act ing from the Middle Eocene to the Qua ter nary. The first three gen er a tions of meso-scale brit tle struc tures were formed un der a transpressional tec tonic re gime dur ing the pre-Late Eocene-Early Mio cene D 1 -D 3 de for ma tion. Gen er ally, the max i mum hor i zon tal stress axis ro tated clock wise from a W-E to an ap prox i mately N-S di rec tion. There af ter, a transtensional tec tonic re gime was char ac ter ized by a WNW-ESE to NNW-SSE ori ented min i mum hor i zon tal stress axis dur ing Middle and Late Mio cene D 4 -D 5 de for ma tion. A gen eral extensional tec tonic re gime in flu enced the struc tural evo lu tion of the area in the Plio cene to Qua ter nary, when a grad ual reori en ta tion of the palaeostress field re sulted in the de vel op ment of vari able, of ten re ac ti vated, fault struc tures.
Abstract:The Súľov Conglomerates represent mass-transport deposits of the Súľov-Domaniža Basin. Their lithosomes are intercalated by claystones of late Thanetian (Zones P3 -P4), early Ypresian (Zones P5 -E2) and late Ypresian to early Lutetian (Zones E5 -E9) age. Claystone interbeds contain rich planktonic and agglutinated microfauna, implying deep-water environments of gravity-flow deposition. The basin was supplied by continental margin deposystems, and filled with submarine landslides, fault-scarp breccias, base-of-slope aprons, debris-flow lobes and distal fans of debrite and turbidite deposits. Synsedimentary tectonics of the Súľov-Domaniža Basin started in the late Thanetian -early Ypresian by normal faulting and disintegration of the orogenic wedge margin. Fault-related fissures were filled by carbonate bedrock breccias and banded crystalline calcite veins (onyxites). The subsidence accelerated during the Ypresian and early Lutetian by gravitational collapse and subcrustal tectonic erosion of the CWC plate. The basin subsided to lower bathyal up to abyssal depth along with downslope accumulation of mass-flow deposits. Tectonic inversion of the basin resulted from the Oligocene -early Miocene transpression (σ 1 rotated from NW-SE to NNW-SSE), which changed to a transpressional regime during the Middle Miocene (σ 1 rotated from NNE-SSW to NE-SW). Late Miocene tectonics were dominated by an extensional regime with σ 3 axis in NNW-SSE orientation.
Ostrá Lúka basalts are a product of the final phase of Neogene volcanism in Central Slovakia. Their major and trace elements composition is alkaline, a feature confirmed by light rare earth elements (LREE) relative enrichment and some incompatible trace elements ratios. The basalts contain rare surrounded gabbro cumulates. Their peculiarity is a strong zonation of olivines and clinopyroxene. The significant zonation probably indicates a short stop of the melt at shallow depth. The Sr, Nd and Pb isotope compositions indicate an origin from a moderately depleted mantle source. The mineral and chemical composition of the basalts is similar to the Pannonian basin alkali basalts and the Western and Central Europe alkali basalts.
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