CGRG Bibliography of Canadian Geomorphology
Search Results
Author : Batterson, M.J.; and Taylor, D.M.
Date : 2003.
Title : Regional till geochemistry and surficial geology of the western Avalon Peninsula and isthmus.
Publication : Current Research (2003). Newfoundland Department of Mines and Energy Geological Survey, Report
Issue : 03-1:
Page(s) : 259-272.
Abstract
Mapping of the surficial geology, and a regional survey of till geochemistry were completed on the western part of the Avalon Peninsula; this included the Isthmus and the southern half of the Bay de Verde Peninsula. Previous reconnaissance surficial mapping was ground-verified, and the ice-flow indicators were mapped to reconstruct the paleo ice-flow history. Till was sampled at a density ranging from 1 sample per 1 km2 in areas of good access to 1 sample per 4 km2 where helicopter support was required. A total of 1042 samples were collected. The entire area, which is subdivided into 4 discrete subareas, was ice-covered during the late Wisconsinan. North of the Doe Hills, ice flow was generally eastward from the main Newfoundland ice cap, likely centred on Middle Ridge in central Newfoundland. Sediment dispersal distances in this area are potentially large (greater than 5 km), as indicated by provenance of clasts within the till. The southern part of the Isthmus was covered by ice from a local source centred on the Collier Bay Brook–Tickle Harbour Station area; ice flow was radial, and dispersal distances are short (much less than 5 km). The southern part of the Bay de Verde Peninsula was covered by northward-flowing ice from the main Avalon dispersal centre at the head of St. Mary’s Bay. This ice flow produced an extensive Rogen moraine field that extends as far north as Makinsons. The central part of the Bay de Verde Peninsula maintained an independent ice centre during the late Wisconsinan, likely deflecting St. Mary's Bay ice into Trinity and Conception bays. Dispersal distances over much of the Bay de Verde Peninsula are likely short (less than 5 km). Areas of glaciofluvial sediment indicate the paths of meltwater during glacial retreat. The effect of regional isostatic rebound was to produce raised marine features around much of the coastline, up to about 16 m above the modern sea level. Drift-exploration programs in these areas should be conducted with caution.
Bibliography of Canadian Geomorphology