ISCI 1A24 Lecture Notes - Lecture 4: Dolomite, Orogeny, Grenville Orogeny
29 Sep 2016
School
Department
Course
Professor
Document Summary
Layer 1 basement, canadian shield (north american craton), 1-3 bya. Layer 2 paleozoic cover (lower paleozoic tropical seas, sedimentary), 600-350 mya. Layer 3 glacial deposits (pleistocene glaciations), 2. 5 mya to present. Layer 4 built landscape, past 300 years. There are large gaps in the geologic record: canadian shield rocks granites and gneisses (metamorphic): Geology varies across the shield made of pieces of small continents joined together by plate tectonic processes, geological provinces (past microcontinents) and suture zones (orogenic belts). Orogenic belts have been eroded folded and deformed rocks of the shield remain. They were once roots of mountains, once buried by 20-25 km of rock (grenville orogeny . Suture zones are weaknesses in the earth"s crust, many faults. Major weakness spreads through ontario between 2 major continental components, joined together by the central metasedimentary belt boundary zone (cmbbz, potential site for earthquake activity. Hamilton and pickering lie close to old suture zone in shield.
