Depositional processes operating on the paleoproterozoic gowganda ice margin

Abstract

Glacial sedimentary rocks of the Huronian Supergroup crop out along the north shore of Lake Huron and were likely deposited on what is thought to have been a divergent continental margin (Fralick and Miall, 1981; 1989). The rocks of the Gowganda Formation record one of three glacial events preserved in the Supergroup and are therefore of interest for developing further glaciomarine models (Puffett, 1974) and furthering understanding of this early stage in Earth’s history. Data has been collected in five main study areas in an attempt to cover as much of the ancient continental margin as possible. The study areas include Espanola, Elliot Lake, Thessalon and Cobalt, Ontario and Marquette, Michigan. There are two glaciogenic formations in the Marquette area of Paleoproterozoic age, the Reany Creek Formation and the Enchantment Lake Formation. The Enchantment Lake Formation has been chronostratigraphically correlated to the Huronian Supergroup based on U-­‐Pb age determination on detrital zircon, 2317±6 Ma, and diagenetic xenotime, 2133±11 Ma (Vallini et al., 2006). As these formations are present in such close proximity to each other, and there are no Archean glacial events recorded in the rest of the Canadian Shield, it is reasonable to correlate them with the Gowganda Formation, the thickest and most commonly preserved of the three Huronian glacial events.