Stepwise clockwise rotation of the Cenozoic stress field in the Western Carpathians as revealed by kinematic analysis of minor faults in the Manín Unit (western Slovakia)

2017 Geological Quarterly  
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 40, 974 01 Banská Bystrica, Slovakia 2 Comenius Uni ver sity in Bratislava, De part ment of Ge ol ogy and Palae on tol ogy, Fac ulty of Nat u ral Sci ences, Mlynská dol ina, Ilkovièova 6, 842 15 Bratislava, Slovakia Šimonová, V., Plašienka, D., 2017. Stepwise clock wise ro ta tion of the Ce no zoic stress field in the West ern Carpathians as re vealed by ki ne matic anal y sis of mi
more » ... ic anal y sis of mi nor faults in the Manín Unit (west ern Slovakia). Geo log i cal Quar terly, 61 (1): 251-264, doi: 10.7306/gq.1340 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.
doi:10.7306/gq.1340 fatcat:wsy4r7h6ifdmdmjy4dvllsawzi