Plate Tectonics and Geology: Terms and Definitions, Quizzes of Geology

Download Plate Tectonics and Geology: Terms and Definitions and more Quizzes Geology in PDF only on Docsity! TERM 1 Paleoclimatic Evidence DEFINITION 1 o Glacial tillites o Glacial striations o Coal deposits o Carbonate deposits o Evaporate deposits ancient climatic zones match up when continents are moved back to their past position TERM 2 Sight of Sea Floor Spreading DEFINITION 2 oMid ocean Ridges. High heat flow o Valley is present along center of ridge o Volcanoes are present along ridge o Earthquakes occur along ridge TERM 3 Inclination DEFINITION 3 The angle of the magnetic field with respect to the horizontal (or dip of the magnetic field) o 90- degrees at north magnetic pole o 0 at equator TERM 4 Lithosphere divided into DEFINITION 4 7 large plates 20 small TERM 5 Lithosphere DEFINITION 5 Rigid, brittle crust and uppermost mantle TERM 6 Asthenosphere DEFINITION 6 Partial molten part of upper mantle below lithosphere TERM 7 What moves plate tectonics? DEFINITION 7 convection in asthenosphere TERM 8 2 types of crust in upper lithosphere DEFINITION 8 oceanic, continental TERM 9 Oceanic crust DEFINITION 9 thin, dense, basaltic TERM 10 Continental crust DEFINITION 10 thick, low density, granitic TERM 21 Wilson Cycles DEFINITION 21 Plate tecontinc model for opening and closing of an ocean basin over time: o Opening of new ocean basin at divergent plate boundary o Seafloor spreading continues and subduction begins o Final stage of continental collision TERM 22 Hypothesis to explain plate motion DEFINITION 22 o Convection cells in the mantle o Ridge-push and slab-pull model o Thermal pull TERM 23 Ridge push-slab pull DEFINITION 23 Crust is heated and expands over a mid-ocean ridge spreading center. Crust tends to slide off the thermal bulge, pushing the rest of the oceanic plate ahead of it This is Ridge-push TERM 24 Rates of seafloor spreading DEFINITION 24 large continents move slower. oceanic plates move more rapidly. no seafloor rocks are older than 200 million years TERM 25 seismic evidence for plate tectonics DEFINITION 25 Inclined zones of earthquake foci dip at about 45 degree angle, near a deep-sea trench. Benioff zones The zone of earthquake foci marks the movement of the subducting plate as it slides into the mantle TERM 26 Gravity evidence DEFINITION 26 forces of gravity over subduction is weaker than normal TERM 27 Focus DEFINITION 27 inside the earth TERM 28 Epicenter DEFINITION 28 point on the ground (top of earth) TERM 29 S-waves DEFINITION 29 travel through solids only. slower than P waves. move side to side TERM 30 P-waves DEFINITION 30 primary, pressure, pull. fastest. travel through solids and liquids TERM 31 Mantle DEFINITION 31 peridodite. not uniform, several concentric layers with differing properties TERM 32 What do curved wave paths indicate? DEFINITION 32 gradual increases in density and seismic wave velocity and depth TERM 33 Dip-slip faults DEFINITION 33 movement is vertical. normal: hanging wall falls. Reverse: hanging wall goes up TERM 34 strike-slip DEFINITION 34 lateral. movement is horizontal TERM 35 types of folds DEFINITION 35 anticline, syncline, monocline, dome, basin TERM 46 evidence for lack of O2 in early atmosphere DEFINITION 46 Lack of oxidized iron in the oldest sedimentary rocks Urananite and pyrite are readily oxidized today, but are found unoxidized in Precambrian sedimentary rocks Archean sedimentary rocks are commonly dark due to the presence of carbon, which would have been oxidized if oxygen had been present Simplest living organisms have an anaerobic metabolism. Killed by oxygen Chemical building blocks of life could not have formed in the presence of oxygen TERM 47 Greenstones DEFINITION 47 Metamorphosed volcanic rocks and sediments derived from the weathering and erosion of the volcanic rocks Commonly have pillow structures (pillow basalts), indicating extrusion under water Green color is from low-grade metamorphism, producing green minerals such as chlorite and hornblende TERM 48 Granulites DEFINITION 48 Highly metamorphosed gneisses (metamorphosed granites) and anorthosites (layered intrusive gabbroic rocks Granulites formed from partially melted crust and sediments in subduction zones. Metamorphism altered the rocks to form granulites TERM 49 Where does the earliest evidence of life occur? DEFINITION 49 archean sedimentary rocks: stromatolytes, microscopic cells of prokaryotes, algal filaments, molecular fossils TERM 50 Origin of life DEFINITION 50 Basic materials from which life oculd have developed initially may have arrived on earth during the archean in carbonaceous chondrites, which contain organic compounds o Carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur TERM 51 4 essential components of life DEFINITION 51 proteins, nucleic acids, organic phosphorus compounds, cell membrane TERM 52 Nucleic acids DEFINITION 52 large complex molecules in cell nucleus o DNA (carries genetic code and can replicate itself) o RNA TERM 53 How can amino acids join with proteins outside of cells? DEFINITION 53 Heating At lower temps in the presence of phosphoric acid Evaporation Freezing Involve water in a dehydration chemical reaction On surface of clay particles TERM 54 Where did life originate? DEFINITION 54 May have avoided UV radiation by living o Deep beneath the water o Beneath the surface of rocks Probably began in the sea, perhaps in areas associated with submarine hydrothermal vents or black smokers TERM 55 Feeding modes DEFINITION 55 fermenter, autotrophs, heterotrophs TERM 56 Fermenter DEFINITION 56 digest chemicals, such as sugar, in the absence of oxygen, to obtain energy. Produce co2 and alcohol. Example: yeast TERM 57 Autotrophs DEFINITION 57 manufacture their own food. Examples: sulfur bacteria, nitrifying bacteria, and photoautotrophs that use photosynthesis TERM 58 Heterotrophs DEFINITION 58 cant make their own food, find nutrients in the environment TERM 59 Evolution of early life DEFINITION 59 Earliest cells had to form and exist in anoxic conditions. Likely to have been anaerobic bacteria or archaea Some of the early organisms became photynthetic, possibly due to a shortage of raw materials for energy Oxygen was a waste product of photosynthesis TERM 60 Consequences of oxygen build-up in atmosphere DEFINITION 60 Ozone layer which absorbs harmful UV radiation, and protected primitive and vulnerable life forms End of banded iron formations which only formed in low, fluctuating O2 conditions Oxidation of iron, leading to the first red beds Aerobic metabolism developed. Uses oxygen to convert food into energy