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Author Ortner, Hugo ♦ Ustaszewski, Michaela ♦ Rittner, Martin
Source SpringerLink
Content type Text
Publisher SP Birkhäuser Verlag Basel
File Format PDF
Copyright Year ©2008
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Earth sciences ♦ Geology, hydrology & meteorology
Subject Keyword Jurassic tectonics ♦ Jurassic sedimentary rocks ♦ Unken syncline ♦ scarp breccia ♦ Northern Calcareous Alps ♦ Austria ♦ Geology
Abstract This study analyses and discusses well preserved examples of Late Jurassic structures in the Northern Calcareous Alps, located at the Loferer Alm, about 35 km southwest of Salzburg. A detailed sedimentary and structural study of the area was carried out for a better understanding of the local Late Jurassic evolution. The Grubhörndl and Schwarzenbergklamm breccias are chaotic, coarse-grained and locally sourced breccias with mountain-sized and hotel-sized clasts, respectively. Both breccias belong to one single body of breccias, the Grubhörndl breccia representing its more proximal and the Schwarzenbergklamm breccia its more distal part, respectively. Breccia deposition occurred during the time of deposition of the Ruhpolding Radiolarite since the Schwarzenbergklamm breccia is underlain and overlain by these radiolarites. Formation of the breccias was related to a major, presumably north-south trending normal fault scarp. It was accompanied and post-dated by west-directed gravitational sliding of the Upper Triassic limestone (“Oberrhätkalk”), which was extended by about 6% on top of a glide plane in underlying marls. The breccia and slide-related structures are sealed and blanketed by Upper Jurassic and Lower Cretaceous sediments. The normal fault scarp, along which the breccia formed, was probably part of a pull-apart basin associated with strike slip movements. On a regional scale, however, we consider this Late Jurassic strike-slip activity in the western part of the Northern Calcareous Alps to be synchronous with gravitational emplacement of “exotic” slides and breccias (Hallstatt mélange), triggered by Late Jurassic shortening in the eastern part of the Northern Calcareous Alps. Hence, two competing processes affected one and the same continental margin.
ISSN 16618726
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2008-10-22
Publisher Place Basel
e-ISSN 16618734
Journal Swiss Journal of Geosciences
Volume Number 101
Issue Number 1
Page Count 17
Starting Page 55
Ending Page 71

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Source: SpringerLink