Geology 4015: Basic Scientific Methods in Geology Comprehensive Exam Questions And Verified Answers A+ Score

area of Canada - correct answers 9,970,610 km² Oldest Known Rock - correct answers Acasta gneiss (Zircon U-Pb age), Slave province NWT Yilgran Craton (Aus) - 4.4 Ga Canada has a large core of old crystalline rocks called ___. - correct answers north american craton Terrane - correct answers refers to a fault bounded crustal block typically thousands of km² in extent superterrane - correct answers several terranes bounded together Craton - correct answers old and stable continental lithosphere province - correct answers a number of crustal pieces with a sharply defined boundary Continental acertion - correct answers plates and pieces of plates welded together by plate collisions North American Craton - correct answers It is a large continental sized block of Archean and Proterozoic rocks that stretches from Mexico up to Canada and Green land (largest in the world). The Green land became detached during the opening of the North Atlantic Ocean 80 million years ago. - the outer edges are buried by younger rocks - igneous and high grade metamorphic rocks - collage of plates and accreted terranes and sedimentary basins - largely exposed in Canada and extends into U.S -amalgamated 2.45 to 1.24 Ga -largest area on earth of exposed Archean Rock -the rocks have been uplifted and eroded over and over - ancient collisions are shown as the mountain roots and craton boundaries - includes mountains (Torngat and Laurentian) difference between Canadian Shield and North American Craton - correct answers Canadian shield is a landform, the North American Craton is the rocks that underline the shield. Canadian shield - correct answers - Canadian shield is about 300-500m above sea level. - patchwork quilt of greenstone belts and granitoid rocks bounded by faults and rifts - 3 Ga of construction How do we know about the deep structure and composition of the North American Craton and Canadian shield? - correct answers From the Lithoprobe project. (Probing the lithosphere) Lithoprobe - correct answers A Canadian organization that involves university researchers, government researchers (federal and Provincial) and certain parts of the mining and petroleum industry - all work together to explore the continental crust in 3D using seismic reflection. It is pretty much completed since 1984. It can interpret up to 70kms below the surface. What is seismic reflection? - correct answers it is a method used in lithoprobe. Sound energy is generated at the surface and travels downward and is reflected back by the rocks. The sensitive microphones (geophones) collect the signal back at the surface and signal is digitally processed. Then geology of the subsurface is interpreted. Who use Lithoprobe and what is it use for? - correct answers - Scientists and researchers use it to study and the discussion of plate tectonic processes of the earth's history. - it is also used by the petroleum industry, gold and base metal exploration industry, diamond exploration industry - it is used for natural hazard assessment to identify any deep seated faults. Slave and Superior Provinces - correct answers - Extensive Greenstone belts: highly altered basalts deposited underwater in ancient oceans (old ocean floor rocks became trapped, squeezed and buried between the landmasses as they came together and broke apart. - largest greenstone belt in Canada is the Abitibi greenstone belt of the Superior Province. - gold and lots of base metals. The largest greenstone belt in Canada is ____. - correct answers the Abitibi greenstone belt of the Superior Province. Greenstone belts - correct answers - Archean - origin of them is debated. 1) they were part of an oceanic plateau that was thrust over the basement when separate crustal blocks collided, therefore they are allochthonous in origin. 2) they are large igneous complexes that intruded into granitic continental blocks during massive rifting events. therefore in situ formation. What is allochthonous mean? - correct answers a large block of rock which formed elsewhere and moved to current place by plate tectonics. The largest crustal block in the North American Craton is ___ - correct answers Superior Province Hot springs in Rockies - correct answers - associated with thrust faulting. -water from the ground that is always at least 5 degrees warmer than the air temperature. -famous Hot Springs: banff, radium, miette - offer information into the chemical and biological processes -hosted in limestone -rainwater or snowmelt from the high mountains gets into fractures and joints in the rocks. - it is warmed, loses density and rises back to the surface -temperature is a function of depth that the water was able to reach. Discuss the temperature and depth relationship of Hot Spring in Rockies. - correct answers -Temperature is a function of depth that the water was able to reach. - generally, temperature will increase by approximately 2.5 degrees every 100 meters (sometimes it mixes with cold surface water though.) -water can go down to around 1 km or more - Banff is between 32 and 47 degrees. Discuss the water chemistry of Hot Springs in Rockies. - correct answers -Rich in Calcium sulfate and Calcium Carbonate. This is because calcite, pyrite and gypsum are dissolving in it) - These minerals precipitate out at the hotsprings - it looks sponge like - a