GEOL 1610 1st EditionLecture 4Outline of Last Lecture I. Igneous RockII. MagmaIII. Lava- important pointsIV. Origins of magmaV. Divergent plate BoundariesVI. Convergent Plate BoundariesVII. CrystallizationVIII. Igneous TexturesIX. Most important intrusive rick texturesX. Chemistry of Igneous RocksXI. What is Bowen’s Reaction series?XII. How do magmas change?XIII. Economic important of igneous rocksOutline of Current Lecture I. This Dynamic Earth- plate tectonicsII. The historical perspectiveIII. What causes all this?IV. Developing the TheoryV. Ocean floor mappingVI. Magnetic stripping and polar reversesVII. Sea Floor SpreadingVIII. Concentration of earthquakesIX. Divergent boundariesThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Current LectureI. This Dynamic Earth a. Plate tectonics influence all processes b. We can’t control them, but we can learn from themII. The historical perspectivea. Plate- large slab of rockb. Earth surface built of these platesc. Large and small plates are movingd. Present day continents are actually fragments of a large continent (Pangaea)III. What causes all this?a. 17th century: people thought the earth was shaped through giant catastrophesb. 19th century: that way of thinking changes, earth was shaped through timec. 3 main layers- crust, mantle, cored. Lithosphere: litho=stone e. Asthenosphere: hot, semi solid materialf. The Americas were torn away from Africa by earthquakes and floodsg. Continental drift 200 billion years ago, Pangaea began to break aparth. 2 large continental masses first then break apart into smaller continent fossils compared on coastsi. These organisms couldn’t have swam across the oceanj. Tree fossils in Antarctica suggest it was closer to the equator while Africa has ice depositsk. People couldn’t accept this idea at firstIV. Developing the Theorya. Debated off and on for decadesV. Ocean floor mappinga. 70% of earth’s surface is covered under oceanb. 16th century open ocean can differc. 1855: underwater mountains, echo sounding devices were used to map the oceanVI. Magnetic stripping and polar reversesa. Magnotemetersb. Recognizing off magnetic variationsc. Rocks on the ocean floors have some magnetic propertiesd. 2 groups= by magnetic properties, pull and pushe. Magnetite in magnetic rocksf. Polarity, normal, and reversedVII. Sea Floor Spreadinga. Ocean ridges-> weak zonesb. Create new oceanic crustc. Earth’s magnetic field have flip floppedd. New crust continually CreatedVIII. Concentration of earthquakesa. Sizemegraphic networkb. Map precisely earthquake zonesc. Confirm sea floor expansion predictionIX. Divergent boundariesa. Magma new oceanic crustb. Spreading made the oceanc. Oceanic- continental convergenced. Long narrow curving trenchese. Oceanic-Oceanic convergencef. 1 is usually subducted and a trench is formedg. Continental-continental convergenceh. Buckle-push upwards or sidewaysi. Transform boundariesj. Plate boundary core, not all are well definedk. Rate of motion: cant really count, plate movement counted with any given