CGRG Bibliography of Canadian Geomorphology
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Author : Daly, J.F.; Belknap, D.F.; and Kelley, J.T.
Date : 2002.
Title : Differential late Holocene sea-level change around Newfoundland
Publication : The 7th International Coastal Symposium (ICS2002). Templepatrick, Northern Ireland. March 25-29, 2002.
Issue :
Page(s) :
Abstract
Differential late Holocene sea-level change around the island of Newfoundland reflects the continuing influence of deglaciation in this region. Previous research with numerical models (Quinlan and Beaumont, 1981) predicted varying Holocene sea-level histories around the island due to glacioisostatic adjustment and the migration of a collapsing forebulge. Analysis of tide-gauge data and salt-marsh stratigraphies from several sites around the island indicates geographically varying sea-level change through the late Holocene. Tide-gauge data constrain the present position of a hinge between areas of rising and falling sea level to the Northern Peninsula. Salt-marsh stratigraphies at four locations around the island provide millenial-scale records of sea-level change through the late Holocene, including data constraining the former position of this hinge. To determine the detailed variation of late Holocene sea-level change in this region, we analyzed salt-marsh deposits at four locations: (A) Port-au-Port peninsula (SW coast), (B) St. Paul's Inlet (central west coast), (C) Deadman's Bay (NE coast), and (D) the Avalon Peninsula (SE coast). Sea-level change at each location is determined by pairing AMS 14C dates with fossil foraminiferal assemblages indicating a paleo-elevation range for the sample. At three locations (A,C,D), the salt-marsh stratigraphies show differing rates of sea-level rise. Our data from the Port-au-Port peninsula agree with previously published data indicating sea-level rise of ~3 m from 3000 yr BP to present. However, at St. Paul's Inlet, less than 200 km northeast, preliminary data constrain the transition from falling to rising sea level to between ~2000 to ~1000 14C yr BP. These data define the passage of a glacioisostatic hinge through this area. Identification of the timing and position of this hinge and differential late Holocene sea-level trends provide important constraints on numerical models predicting crustal isostatic responses to deglaciation.
Bibliography of Canadian Geomorphology