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Case Study: Don Valley Brickyard

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Sarah Hall, 1000680872 September 23, 2014
Lab 1: Don Valley Brickyard Short Pre-Lab Report
1. The geology of Ontario is divided into three layers of rock. The first layer, Precambrian Canadian Shield rocks, is composed of mainly igneous and metamorphic rocks from the Precambrian Eon. This layer is the eldest at approximately 3-0.8x109 years old and is therefore the bottom-most layer (L). Although this layer is largely found in the Canadian Shield region of Ontario, glacial erratics from the Precambrian layer can be found at the Don Valley Brickyard (L). In the GTA, younger sediments and rocks cover the Precambrian rock layer (L). The second layer is Paleozoic rock, composed of sedimentary rocks
. It was deposited 600-400 million years …show more content…

The third and topmost layer of geological deposits is the Pleistocene sediment, from the Quaternary Period, which can date up to 1.7 million years old (L). This layer contains sediments of Holocene from ten thousand years ago as well as Pleistocene from 1.7MY to 10KY(L). Continent wide ice sheets deposited the glacial sediments during numerous ice ages (DVLR) and can be seen at Don Valley Brickyard. The York Till is above the bedrock, and was left 135,00 years ago by an Illinoian ice sheet. Above the till is the 80,000-year-old Don Formation that was caused by the Sangamon Interglacial, and indicates climate change by the alternation of sand and mud. Above the Don Formation, all other deposits are from the Wisconsin Glaciation. The Scarborough Formation consists of clay and then sands, and was formed 60,000 years ago. Above this is the Sunnybrook Drift and the Thorncliffe Formation from 45,000 years ago consisting of seminary …show more content…

The 440 million year old Georgian Bay Formation is largely composed of fossiliferous grey-black shale (L1R). It also consists grey fine-grained limestone, sandstone and green/grey siltstone interbedded with green/grey and blue/grey shales (Bond et. al. 1976). The frequency of hard rock units increases toward the top of the formation. Recurrent tropical storms across the Ordovician seas caused the formation of shady, thin limestone with wave ripples on top. Numerous fossils can be found in the siltstones and limestone including molluscs, crinoids and gastropods

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