Sedimentological distinction in glacigenic sediments between load casts induced by periglacial processes from those induced by seismic shocks

Load ing pro cesses and the re sult ing load struc tures in duced by pro cesses re lated to periglacial con di tions are com pared tothose in duced by seis mic shocks. The load struc tures them selves are rel a tively eas ily rec og niz able but the re spon si ble trig -ger mech a nism is, though de pend ing on the geo log i cal con text, com monly dif fi cult to es tab lish. Load struc tures like loadcasts, pseudonodules, ball-and-pil low struc tures and flame struc tures are com monly as cribed to instable den sity gra di entswithin sed i ments and to dif fer en tial load ing, but their for ma tion al ways re quires liq ue fac tion. In glacigenic sed i ments, de for -ma tion struc tures have most com monly been as cribed to periglacial pro cesses (as a type of cryoturbations), but it be comesever more clear that glacigenic sed i ments can, par tic u larly dur ing ice-front fluc tu a tions, be af fected by fault ing-re lated earth -quakes (due to glacio-iso static ad just ment), and the thus trig gered seis mic shocks may re sult in de for ma tions, in clud ing –most com monly – load struc tures. We in ven tory the ev i dence that may help to dis tin guish, on the ba sis of tex tural and struc -tural fea tures, load struc tures with a seis mic or i gin from those that re sult from periglacial pro cesses, tak ing into ac count thattruly di ag nos tic cri te ria do not ex ist.