Rn. Hiscott et Ae. Aksu, SUBMARINE DEBRIS FLOWS AND CONTINENTAL-SLOPE EVOLUTION IN FRONT OF QUATERNARY ICE SHEETS, BAFFIN-BAY, CANADIAN ARCTIC, AAPG bulletin, 78(3), 1994, pp. 445-460
Baffin Bay is a semi-enclosed extension of the Labrador Sea in the Can
adian Arctic. The upper Pliocene and Quaternary successions beneath th
e continental slope contain important slumps and debris-flow deposits.
New high-resolution single-channel seismic data have been acquired fr
om a 500 to 600-m-deep transverse trough that indents the shelf in an
area where glacial outflow was focused during the Pliocene and Pleisto
cene. Major shelf-edge progradation occurred both inside and on the fl
anks of the transverse trough. In the lower slope, several large debri
s flows carried proglacial deposits into the deep basin. The largest o
f these debris flows dramatically reshaped the sea floor by reducing b
ottom slopes both by proximal erosion and distal thickening of the deb
ris-flow deposit. Subsequently, the lower slope was starved of terrige
nous input, and the upper slope was steepened by accumulation of basin
ward thinning wedges of mass flow deposits. The processes of emplaceme
nt of large debris flows, slope reshaping, and out-of-phase accumulati
on identified in upper and lower slope areas of Baffin Bay are relevan
t to the interpretation of other line-source margins affected by major
sea level falls or changes in sediment influx, including siliciclasti
c slope aprons and carbonate platform margins.