Relationships Between Sediment Mass-Failure Modes And Magnitudes In The Evolution Of The Scotian Slope, Offshore Nova Scotia

摘要

The role of seabed failure in the regional development ofrncontinental margins is not well reported in the literature.rnRecently, large amounts of scientific and industry seismicrnreflection data have been collected along the Scotian margin,rnoffshore Nova Scotia. The new datasets allow for the regionalrnassessment of the complete range of magnitude and recurrencernof seabed failure for this area, from a time dominated byrnprodeltaic sedimentation to a time dominated by proglacialrnsedimentation. The results show that large scale seabedrnfailure was uncommon during the early Tertiary, but becamernwidespread after ~ 40 Ma. Failure deposits are more abundantrnon the eastern and western portions of the margin compared tornthe central portion. The largest failure deposits observed onrnthe margin occurred during non-glacial periods, whereas thernhighest recurrence of failure occurred during periods ofrndeglaciation. The modern slope of the seabed, from shelfrnbreak to continental rise, appears to be related to seabedrnfailure history, with exponential slope curvature in areas ofrnlarge-scale or abundant failure and linear slope curvature inrnareas of small-scale failure. Several glacial and non-glacialrnrelated trigger mechanisms are possible, but more research andrnimproved age control is required to identify whichrnwere active.