Holocene Relative Sea-Level Change in Nova Scotia

Abstract

Core samples collected around Atlantic Canada, specifically from the West Head salt marsh, Chezzetcook Inlet, enable temporal and spatial examination of benthic foraminiferal assemblages. Benthic foraminiferal zonations, representing specific environments above mean sea level, occur in salt marshes. Trochammina macrescens and Tiphotrocha comprimata indicate the higher high water (HHW) level, the maximum tidal extent during any time period and the most accurate former sea-level marker. Collected core samples yielded nine accurate sea-level points and one additional point was extrapolated from Baie Verte. Carbon-14 dating (corrected to sidereal years) permits the construction of a Holocene relative sea-level (RSL) curve by plotting corrected 14C dates (temporal) against corresponding sample depths (spatial). The curve produced for the Atlantic coast of Nova Scotia shows a rise in RSL for the last 7859 years and, more specifically, a RSL rise in Chezzetcook for 4247 years. RSL curves are variable across Atlantic Canada and local isostatic adjustment associated with peripheral forebulge migration following deglaciation is probably the source of the overall variation. However, an acceleration observed is between 5295-3819 ybp in this curve and a previous curve from Northern Nova Scotia is hypothesised to be a eustatic response, possibly correlated with an oscillation reported in South Carolina.

Keywords: foraminifera, salt marsh, Chezzetcook Inlet, Holocene, relative sea level, peripheral forebulge, eustatic Pages: 84 Supervisor: David Scott