TY  - JOUR
A1  - Weidinger, Johannes T.
A1  - Korup, Oliver
A1  - Munack, Henry
A1  - Altenberger, Uwe
A1  - Dunning, Stuart A.
A1  - Tippelt, Gerold
A1  - Lottermoser, Werner
T1  - Giant rockslides from the inside
T2  - Earth & planetary science letters
N2  - The growing body of research on large-scale mass wasting events so far has only scarcely investigated the sedimentology of chaotic deposits from non-volcanic terrestrial landslides such that any overarching and systematic terminological framework remains elusive. Yet recent work has emphasized the need for better understanding the internal structure and composition of rockslide deposits as a means to characterise the mechanics during the final stages of runout and emplacement. We offer a comprehensive overview on the occurrence of rock fragmentation and frictional melt both at different geographic locations, and different sections within large (>10(6) m(3)) rockslide masses. We argue that exposures of pervasively fragmented and interlocked jigsaw-cracked rock masses; basal melange containing rip-up clasts and phantom blocks; micro-breccia; and thin bands of basal frictionite are indispensable clues for identifying deposits from giant rockslides that may remain morphologically inconspicuous otherwise. These sedimentary assemblages are diagnostic tools for distinguishing large rockslide debris from macro and microscopically similar glacial deposits, tectonic fault-zone breccias, and impact breccias, and thus help avoid palaeoclimatic and tectonic misinterpretations, let alone misestimates of the hazard from giant rockslides. Moreover, experimental results from Mossbauer spectroscopy of frictionite samples support visual interpretations of thin sections, and demonstrate that short-lived (<10 s) friction-induced partial melting at temperatures >1500 degrees C in the absence of water occurred at the base of several giant moving rockslides. This finding supports previous theories of dry excess runout accompanied by comminution of rock masses down to gm-scale, and indicates that catastrophic motion of large fragmenting rock masses does not require water as a potential lubricant.
KW  - landslide
KW  - petrography
KW  - frictional melt
KW  - pseudotachylyte
KW  - breccia
KW  - Mossbauer spectroscopy
Y1  - 2014
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/38027
SN  - 0012-821X
SN  - 1385-013X
VL  - 389
SP  - 62
EP  - 73
PB  - Elsevier
CY  - Amsterdam
ER  -