Rock avalanches are a form of rapid, long-runout landslides. Their deposits can cover large areas (typically km2) with fragmented debris up to 10s-100s m thick. The final deposit fabric is influenced by many overlapping factors, such as source structures, lithology (i.e. material properties), topographic feedback, substrate interaction, and emplacement processes, as well as our reliance of suitable outcrops (i.e. sample bias). To resolve some of the complexity in their sedimentology and gain insights into their emplacement dynamics, a case study in a largely monolithologic (carbonates) and well-exposed rock avalanche deposit in the Tyrolean Alps of Austria was carried out. Besides eliminating changes in lithology from the causal equation, the effects of external influences such as topography or substrate interaction are ruled out through detailed facies mapping and careful selection of sample sites. Several depositional facies are identified which relate directly to emplacement processes. These facies are found throughout the deposit in vertical and horizontal directions, evidencing highly heterogeneous stress distributions in time and space during emplacement. In this talk, examples of rock avalanche facies in different deposits and settings are introduced and the detailed case study of a (lithologically) relatively simple deposit is presented to outline universally valid versus site-specific depositional structures and facies. The major aim of this study was to document solid evidence of rock avalanche emplacement processes in the deposits in order to determine the most competitive of the myriad rock avalanche emplacement
hypotheses proposed in the literature.

The Natural Resources & Environmental Studies Institute (NRESi) at UNBC hosts a weekly lecture series at the Prince George campus. Anyone from the university or wider community with interest in the topic area is welcome to attend. Presentations are also made available to remote participants through Livestream and Blue Jeans. Go to http://www.unbc.ca/nres-institute/colloquium-webcasts to view the presentation remotely.

Past NRESi colloquium presentations and special lectures can be viewed on our video archive, available here.