REGIONAL ICE-FLOW MAPPING, SURFICIAL GEOLOGY AND TILL GEOCHEMISTRY OF THE NORTHERN BURIN PENINSULA AND ADJACENT PLACENTIA BAY

The entire study area appears to have been covered by late Wisconsinan ice. Two major ice flows were identified; an early south-southeastward event from a source to the north crossed the entire area, followed by a westward flow in the southern half of the area and a southwestward flow into Fortune Bay in the central part; the early flow was likely main Newfoundland ice from a centre to the north. It is well defined in the striation record, in terrestrial landforms, and on the multibeam data from Placentia Bay, where southeastward-trending submerged drumlins are clearly evident. The westward flow was from an offshore source or from the Avalon Peninsula; this is suggested from the striation record but appears to have little geomorphic signature. The southwestward flow into Fortune Bay is likely a late-stage topographically controlled event. Much of the northern part is covered by a blanket of locally derived granite-rich till; flutes are common. The remainder of the area has a thin, discontinuous veneer of till and numerous bedrock outcrops. Glaciofluvial sediments are confined to the larger valleys, commonly feeding into glaciomarine deposits. The effect of regional isostatic rebound was to produce raised marine features around much of the coastlines of Fortune and Placentia bays up to about 20 m asl. Material for radiocarbon dating has not been found in these areas to assist in the definition of a relative sea-level curve or to provide dates on regional deglaciation. Drift-exploration programs should carefully consider the affect the distribution of raised marine and glaciofluvial deposits will have on their sampling programs, or in interpreting data produced from such surveys.