Geology Terms: Himalaya Formation, Indian Ocean Plate Subduction, & Appalachian Features, Quizzes of Geology

Download Geology Terms: Himalaya Formation, Indian Ocean Plate Subduction, & Appalachian Features and more Quizzes Geology in PDF only on Docsity! TERM 1 Formation of Himalayas DEFINITION 1 India and Asia collision 40-50 million years ago -movement b4 collision: 10+cm per year -movement after collision: 5 cm per year in last 10mil yrs, india slides NE beneath main boundry fault -2nd slice of crust is forced up on the indian subcontinent creating the Himalayas TERM 2 Indian Ocean Plate Subduction DEFINITION 2 6070 mil yrs ago india is 8000km south from current location TERM 3 Composition of mt. Everest DEFINITION 3 top: limestone bottom: mudstone TERM 4 crinoid DEFINITION 4 sea lily fossil found t top of Everest (280-320 mill yrs old) TERM 5 4 regions of southern part of Appalachain Mt DEFINITION 5 App Plateau-completely flat, unmetamorphosed sediments w age of 570-290 mill years Vally & ridge province- same sediments except r tightly folded n thrust faulted; barely metamorphosed Blue Ridge-rocks hv been folded n refolded many times & subjected to high grade metamorphism Piedmont- sed n volcanic rocks. intense folding; metamorphic grade is much more variable TERM 6 Bluemont Province DEFINITION 6 three rcok types 1. oldest- high grade gneiss at least 1000mill yrs old 2. clastic sediment on cont crust in rift environment in Late Proterozoic (600-800mil yrs) 3. Early Cambrian clastic sediment deposited on passive contiental margin TERM 7 blind thruts DEFINITION 7 thrusts that do not reach the surface TERM 8 Piedmont province DEFINITION 8 inner piedmont- high grade meta rock intruded by bodies of igneous rock charlotte belt- low grade metamorphosed sed rocks carolina slate belt-metamorphosed volcano material. started 650-500 mill yers ago TERM 9 Orogenies DEFINITION 9 major mt. building evens recognized in App mt. Alleghanian, Acadian, Taconic, Avalonian TERM 10 J. Tuzo Wilson DEFINITION 10 proposed 1st model on plate tectonics forming App mountains TERM 21 elastic rebound hypothesis DEFINITION 21 When slip on the fault occurs, the two blocks side past each other, relieving stress on the fault. Because the stress is removed, the rock on either side of the fault bounces back to its original shape, releasing elastic strain energy as shock waves. TERM 22 Isoseismal lines DEFINITION 22 Lines that connect values of equal earthquake intensity. TERM 23 Inge Lehmann DEFINITION 23 Was a pioneering scientist at a time when few women had careers in science and mathematics........ TERM 24 velocity of seismic waves DEFINITION 24 Is directly proportional to the rigidity of the rocks through which they pass. Seismic waves travel most rapidly in rigid materials which elastically spring back to their original shapes when the stress is removed. The more rigid the rock, the greater the velocity at which the seismic wave travels. TERM 25 partial melting DEFINITION 25 Partial melting of the ultramafic rocks is thought to occur due to the particular combination of pressures and temperatures. TERM 26 kimberlite pipes DEFINITION 26 Used to bring up ultramafic rocks from the upper mantle. TERM 27 oceanic trenches DEFINITION 27 A narrow, deep trough parallel to the edge of a continent or an island arc. -The slope of the trench is typically 4-5 degrees on the upper part, steepening to 10-15 or even more on the lower part. TERM 28 mid-oceanic ridges DEFINITION 28 are large linear mountain ranges that rise from the depths of every ocean basin, and are interconnected in a worldwide network over 60,000 km long. -In the Atlantic the ridge is at the centre of the basin. -In the Pacific ocean, the ridge is near the eastern margin. TERM 29 rift valley DEFINITION 29 -Located in the Pacific Ocean -Is a large crack apparently of tensional origin, and runs down the crest of the ridges. -The rift valleys are generally 1 to 2 km deep and several kilometers wide. TERM 30 Alfred Wegener DEFINITION 30 German meteorologist and arctic explorer who discovered the basic concept of continental drift in 1915. TERM 31 panthalassa DEFINITION 31 single ocean around pangea TERM 32 laurasia DEFINITION 32 northamerica, europe, and asia TERM 33 gondwanaland DEFINITION 33 southamerica, africa, india, antartica, and australia TERM 34 mesosaurus DEFINITION 34 a permian age freshwater reptile whose fossil remains have only been found in eastern South America and southern Africa. TERM 35 lystrosaurus DEFINITION 35 A land reptile from the Triassic period whose fossil remains have been found in Africa, India, and Antarctica -First Lystrosaurus fossils in Antarctica were found by a USA expedition in 1969. TERM 46 metamorphism DEFINITION 46 Metamorphism is the solid-state recrystallization of pre- existing rocks due to changes in physical and chemical conditions, primarily heat, pressure, and the introduction of chemically active fluids. TERM 47 types of foliation DEFINITION 47 slate- fine grained; splits easily alont flat parallel lines schist- coarse grained; oriented approx parallel 2 eachother gneisscomposed of dark & light parts. dark parts r foliated whereas light r randomly oriented TERM 48 polymorphs DEFINITION 48 same chem comp but diff internal crystal structure TERM 49 Alumino silicate polymorphs Al2SiO5 DEFINITION 49 andalusite kyanite silliminite TERM 50 meta aereole DEFINITION 50 zone around igneous body that meta changes hv happened TERM 51 meta zone DEFINITION 51 area btwn isograds TERM 52 meta grade DEFINITION 52 measure of relative intensity of meta TERM 53 distribution of worlds water DEFINITION 53 97.2-ocean 2.8-other in other: 77% ice caps & glaciers 22% ground water 1% lakes and rivers TERM 54 hydrolic gradient DEFINITION 54 slope of water table TERM 55 darcy's law DEFINITION 55 (permiability X vert distance)/horizontal distance=velocity TERM 56 drawdown DEFINITION 56 the lowering of the watertable due to the MECHANICAL pumping of a well to create a 3-dcone of depression TERM 57 tensional stress DEFINITION 57 rock pulled apart TERM 58 shear stress DEFINITION 58 rocks slide by eachother causing friction TERM 59 dilation DEFINITION 59 change in volume (usually negative TERM 60 stress DEFINITION 60 force divided by surface area TERM 71 James Hutton DEFINITION 71 founder of modern geology Principle of uniformitarianism TERM 72 van der walls bonds DEFINITION 72 all electrns r on one side, so protons in nucleus r exposed & attract other electrons TERM 73 properties of minerals DEFINITION 73 color, hardness, cleavage, crystal form, streak, luster,n fracture specific gravity TERM 74 Felsic DEFINITION 74 more that 65% silica content lowest density, melting pt, n tendency to form lava highest tendency 2 form pyroclastics cannot melt overlying basalt TERM 75 Mafic DEFINITION 75 less than 50% silica content highest density, melting pt, n tendency of forming lava lowest chance 2 form pyroclastics can melt overlying granite TERM 76 extrusive rocks intrusive rocks DEFINITION 76 rocks formed above earths surface rocks formed beneath earth TERM 77 Bowens Reaction Series DEFINITION 77 w/ falling temp, minerals crystalize in this order: olivine pyroxene amphibole biotite muscovite quartz TERM 78 sill dike laccolith DEFINITION 78 runs in btwn layers on country rock cuts across layers of country rock like sill except domes upwards TERM 79 stoping xenolith assimilation DEFINITION 79 upward movement of magma by fracturing overlying rock inclusion of unmelted country rock in igneous rock magma melts country rock forming new material TERM 80 Gabbro DEFINITION 80 coarse grained mafic rock TERM 81 Basalt DEFINITION 81 a fine grained mafic rock mostly in ocean crust TERM 82 granite DEFINITION 82 coarse grained felsic rock found in continental crust only TERM 83 rhyolite DEFINITION 83 fine grained felsic rock TERM 84 Eratosthenes DEFINITION 84 first to calculate radius of earth in 230 bc radius of earth:6336 km TERM 85 lithodomous DEFINITION 85 intertidal clam