Publication Date:
2022-08-30
Description:
Sedimentary stratigraphy and facies analysis along with seismostratigraphic and multibeam bathymetry
data are used to reconstruct the last glacial impact on the Arliss Plateau (AP) and attendant sedimentation
in the adjacent Chukchi Basin (CB) in the western Arctic Ocean off the East Siberian margin.
Sediment core ARA02B/16B-GC from the AP lower slope captures glacier-related depositional history
during the last estimated ca. 100 ka (Marine Isotope Stage, MIS 1 to 5c) based on regional lithostratigraphic
correlation. The sedimentary record shows distinguishable interglacial (interstadial) and glacial
(stadial) patterns. The identified sedimentary facies reflect several modes of glaciogenic deposition by
drifting icebergs, suspension settling from turbid meltwater plumes and/or detached underflows, and
turbidity currents. Based on strong seismic reflectors related to lithological boundaries, a downslope
subbottom profile from AP to CB is divided into seismostratigraphic units (SSU) 1 and 2 corresponding in
the core record to MIS 1e3 and MIS 3-5c, respectively. An acoustically transparent lens within SSU 2
correlates on the upper slope to debris lobes downslope from the AP top covered by megascale glacial
lineations. This geomorphic/sedimentary pattern indicates a glacial erosional impact on the AP and
proglacial deposition of eroded sediments on the slope and in the basin. Based on the developed sediment
stratigraphy and facies analysis, the last debris lobe horizon was deposited in glacial/deglacial
environments during late MIS 4 to early MIS 3. The absence of similar glaciogenic debris lobes within SSU
1 indicates no direct glacial impact on the AP during the Last Glacial Maximum (LGM). These results
suggest that the last glacial erosion of the AP occurred during or immediately afterMIS 4, possibly related
to major glaciation in northern Siberia at ~50e70 ka.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
NonPeerReviewed