Gowganda conglomerate is a sedimentary rock, found in Elliot Lake, middle Precambrian, Huronian supergroup rocks, 2,200 – 2,450 million years ago. Gowganda conglomerate is a very striking material. Generally it consists of rounded boulders and pebbles of pink granite and other rocks in a fine grained grey mud. The rock has a uniform hardness, breaking across the boulders and grey mud evenly. Geologists think that the gowganda conglomerate is a tillite, formed by glaciation during the middle Precambrian. In some areas dropped stones are found finely layered (varved) clays. This is the evidence for thinking that icebergs dropped the stones into the mud. Sometimes pieces of gowganda conglomerate can be found in gravel pits and at beaches along Lake Huron and throughout southern Ontario. This material was collected by glacial ice in the area below during the Pleistocene Epoch, and transported to the south.
The Gowganda conglomerate on a sunny day in the Peter Russell Rock Garden.
A close-up of the Gowganda conglomerate showing it's striking structure.
