All lectures for EESA06- comprehensive and very detailed, 24 pages, useful for final exam. good luck!

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University of Toronto Scarborough
Environmental Science
Nick Eyles

Lecture 3- EESA06 Modern planet earth is not fixed, constantly moving and changing Earth history is all about the history of the oceans, examine how oceans form Why do supercontinents dome upwards? plume of hot mantle plastic rock that rises underneath because its pushed due to warming, develops triple junction, they form the triple junction, each of the arms are called a rift, the floor of the rift is usually going down, which is called subsiding if you look at the evolution of the triple junction, only one rift opens up, only one of them develops to an ocean, we can then identify failed rifts, great openings for gas because of organic materials, sediments, that then gets buried and gets cooked, petroleum geologists North America- one major system that opened up and made the Atlantic Ocean, preservation of failed rifts within a continent, the Ottawa River valley and St. Lawrence are examples of failed rifts Mississippi is following the grain of structure of failed rifts, control where large rivers flow and also generate earthquake, frequent earthquake in Ottawa Stage 1: East Africa rift system, there is a plume that is pulling it apart, continental breakup and birth of a new ocean, the Somalian plate (horn of Africa), will break away and become its own piece of continental crust, the triple junction, one of the arms will be an ocean, Red Sea (future ocean), Gulf of Aden, and small rift, you can see fissures, (cracks in the earths crust) magma rises, fissures, flood assaults, lava flows that go for many kilometres, fluid lava, green crater, If we are opening a new ocean, we are forcing plates apart, the Arabian plate, its been pushed north by the widening of the Red Sea, the black line on tops are mountains that are getting larger, Canyon with white volcanic ash, ash layers, can date them precisely, because our species stared in East African Rift, Kariandusi (ash layer) layer of hand axes, 2 million years old, homo habilis- handy man earliest human that made tools, brain sizes increase, 650 cc, now we have 1200 cc, major steps in human evolution when the lakes are at their maximum size, environment- large lakes = lots of water, lots of food, diverse rich ecosystem, key steps in human evolution took place when there was an abundance of food Afar triangle, (Arabian plate, Ethiopian) Where Lucy came from, preceding early hominid, australopithecine, right in triple junction, driest place in Africa, the Danakil desert, you see a shield volcano, low slope angles, Lava lake, overflows and then spews out, its building an ocean floor, sulphur dioxide gasses, key point why its safe, because gases can release easily, while pointy the magma is more stiffer and gasses dont come out easily and only comes out in major eruptions, 280 million years ago, coincides with major eruptions in Western India, called the Deccan lava, emerging evidence that gas spewed out and caused extinction Stage 2: Red Sea (oceans are widening all the time, seas dont, its a little embryonic ocean), green belt (Nile River), Nile delta, without it cant really live there, Nile is only there because it is flowing from Ethiopia, built huge temple complexes, Pyramids are made of limestone (rock that is made of fossil organisms), while in the south, it is mainly made up by granite, Dsert, Egyptian word, bioclastic limestine for Eocene age, made up of broken fossils, called foraminifera (simple organisms), called numbulites, they look like coins, used tura limestone because it can be polished, mirror-like quality, facing stone, would look like mirror, thin gold-cap on top of the pyramid, called electrum, revered because it though to be the skin of the god, pylon at karnak temple complex, Nubian sandstone, depictions of people building the pyramids, holding on cables and building pylons, famous hypostyle hall, Nubian sandstone, use of columns, a luxor, wouldve laid on large pot, mud around it, build a ramp until they have the whole column, paint it after getting rid of the mud There are a lot of granite in Toronto, but no tors, glaciers, would knock the boulders down, pushed down by ice sheets, called erratics, glacially transported borders Obelisk- any country that invaded Egypt decided to take one of it, it is a base made out of limestone, only one that depicts the obelisk being moved, granite quarries, unifinished obelisk at aswan, biggest one ever produced, 1200 tonnes, 42m long, has an ore, set fires of trench and broken it pouring water, record of how they work the obelisks Gold is associated with granite, gold was throught to be the skin of the gods, igneous rocks, Nubians brining tributes of gold, King Tutankhamen, pick up metals, dissolve metals until you see veins of gold associated with granite, 3150 years old, oldest known geological map, written on papyrus for ramesses iv, 1156 1150 bc, by ammenakhate, called a WADI (canyon) Simon Winchester, the map that changed the world, map in 1815, europe, part of industrial revolution, geology maps is needed to find coal, limestone (natural non- renewable resources), by William smith, thought to be first but it was actually ancient Egypt First Canadian geology map, 1866, William logan, pioneer in mapping and rocks in southern Ontario, purpose of this was to find COAL, turns out that southern Ontario did not have coal, no coal problem they solved it 1867 by getting it from Nova Scotia, Confederation (birth of Canada), done for economic purposes, many of the rocks we have for rock types are from Egyptian terms Salt, sinai, type of granite common in Egypt, porphyry- igneous rock with very large crystals, granite countertops, by crystals, Egyptian porphyry is deep read almost purple colour, romans loved it, got exported to Istanbul and everywhere NAF- north Anatolian fault, northern end in the Arabian plate, Istanbul, DSFS- dead sea fault zone, the Arabian plate is sliding to the west, to Lebanon mostly Israel, west side of dsfs, deadly fault, plates are sliding past each other, because the dead sea is opening and pushing plates apart Jordan is part of Arabian plate moving north brushing against Israel and Egypt, dead sea, produces a lot of concentration of salt, 10x normal sea water, impossible to swim, you just float, brine, very salty water, lowest place of earth, the DSFS is actually another type of rift, the floor is subsiding well below sea level, the dead sea level is actually going down because people use the water since they use brine for salt, rare earths for cell phones, has exposed the old sediments that used to be on the floor of the Dead Sea, layers of minerals are folded and disturbed, can see evidence of ancient earthquakes, seismites, layers of rocks and minerals that have been deformed by major earthquakes, we are interested in the frequency of old earthquakes because you can have a clue of what the next earthquake must be, gives an idea of timing, studying ancient sediments, identifying seismites, dating seismites and then predicting Dead sea scroll- written records of earthquakes, combines the information of seismites with historical records to see the patterns of earthquakes many years ago, plate boundary, Small roman community, hippos, destroyed by earthquake, the columns dropped because of the major earthquakes, you can get information of the columns by the direction, where the earthquake was located, Eastern side of the fault, beehive type mountains, very narrow canyon where you follow, petra, or rocks, building into rocks, excavated into size of canyons, entrance to ancient city, abandoned 363AD because of an earthquake, covered in sand, forgot about it, only discovered in 1815, famous fable spirit city, collapsed columns, coins below the columns, dated it, Arabian plate, moving northwards, making mountains up north, western border is moving up the dead sea fault zone and turkey wants to get out of it so tis moving west, along the north alitanian fault, Stage 3: Atlantic Ocean Lecture 4 Goes through the cycle of rifting and then a ridge valley because they begin to be subducted under the continent, as you move away from mid ocean ridge, the thickness of the crust actually increases because the oceanic crust cools and thickens, as you go away from the ridge other side Young ocean floor crust is relatively thin and not deep, it begins to subduct as the crust gets thicker, new face in the ocean, new ocean forming is pushing land apart, the ocean is like an accordion, it opens and closes, the history of the continent is dictated by the history of the ocean, the earth history is controlled by ocean history Dependent on many ocean crust because they are mineral rich, tell a lot about earth history Jokulhlaups! volcanic activity under glaciers, jokulha is mountain, laups is leap, Mid ocean ridge, they are basically underground volcanoes, mid ocean ridge as a mountain chain, it is not continuous, there are cracks along the ridges and they are called fractures, very special role, they enable spreading to take place on the curved earth surface, Dikes or dykes, result of hot magma intruding to older rock, along fractures, if yo
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