New Concepts on Mass Wasting Phenomena at Passive and Active Margins of the Alpine Tethys: Famous Classical Outcrops in the Berchtesgaden - Salzburg Alps Revisited. Part A: Jurassic Slide/Debrite Complexes Triggered by Syn-Sedimentary Block Faulting

摘要

Jurassic strata exposed in outcrops along road cuts and trails as well as saw cut wall sections of "technical marmor" quarries at Adnet close to Salzburg and Waidring were studied for their depositional features, their geometries of sediment bodies, syn-depositional deformation and re-deposition structures as well as tectonic features. A spectacular mass wasting complex at Rote Wand/ Mount Stcinplatte near Waidring (Austria, Tirol) was studied. Development of this complex indicates that in a first phase downward gliding almost intact slide blocks plugged into the underlying bedded nodular strata. In turn, this slide was immediately overrun by semi-consolidated slumped deposits, which partly disintegrated into pebbly mudstones. On top of the mass sealing by three debris flows is observed. We assume that the emplacement of the slide/slump complex occurred as one single event triggered by syn-sedimentary block faulting at the passive Early Jurassic Alpine margin. Eventually deposition of the first debrite covering the slide/slump complex was also related to this phase. In addition, a broad spectrum of mass wasting deposits is described from Liassic strata on the paleoslope of the drowned Rhaetian reef complex at Adnet and the surrounding basins.