Publikationsdatum:
1991-01-01
Beschreibung:
Cambridge Fiord functions as a major outlet trough whenever Laurentide ice approaches the eastern coast of Baffin Island. During the last glacial maximum (late Foxe glaciation), an outlet glacier occupied most of the fiord, possibly terminating as far seaward as Buchan Gulf. Glacier retreat began prior to 8800 yr B.P. and was punctuated by the formation of two onshore moraines with upper age limits of 7900 and 7200 yr B.P. Correlative offshore moraines (recognized on seismic reflection profiles) formed prominent submarine sills which partitioned the fiord into three basins. These formed effective sediment traps that restricted the seaward migration of debris flows and turbidites, thus facilitating the accumulation of thick (〉 100 m) stratified glacialmarine sediments in the inner fiord. Correlations of onshore and offshore moraines allow time lines to be placed within an offshore seismic stratigraphic section that is inaccessible to piston coring. Resultant estimates of sediment accumulation rates give a mean value of 2.34 × 106 m3/yer for deposits trapped in the inner fiord basins. These thick sequences of sediments do not represent extended Foxe/Wisconsin time periods, but, rather, were rapidly deposited in the inner fiord during the last deglaciation.
Print ISSN:
0033-5894
Digitale ISSN:
1096-0287
Thema:
Geographie
,
Geologie und Paläontologie
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