Details Title: EOS 11 Description: ROCKS CLASS Total Flash Cards: 71 Created: 10/02/2007 12:50:05		New Users: To study from this flashcard set, or to create your own your own study flash cards, REGISTER HERE. Existing Users: CLICK HERE. Additional Geology Flashcards
Cards in this set: Term What are the five major pieces of evidence cited by Alfred Wegener in support of continental drift?- Definition 1. Fit of the Continents 2. Distribution of Glacial Deposits 3. Distribution of Mountain Belts and Rocks 4. Distribution of Fossils 5. Distribution of Climatic Zones Term What are the five major pieces of evidence cited by Alfred Wegener in support of continental drift?- Definition 1. Fit of the Continents 2. Distribution of Glacial Deposits 3. Distribution of Mountain Belts and Rocks 4. Distribution of Fossils 5. Distribution of Climatic Zones Term why should scientists never use the term truth or proof when referring to the scientific explanations? Definition unless with math, science never proves anything Term what is a scientific model Definition an idea or construct that provides an explanation of how something in the world works Term whats the difference between how poeple use teh term theory in everyday language and how scientists use the word? Definition collogquial-I believe-a set of statements or principles to explain a group or fact scientific:the branch of science or art consisting of its explanatory statements accepted principles and methods of analysis Term What is meant by testing of 'multiple working hypotheses'? Definition a statement about the natural worlds that leads to testable prediciotns... usually an if then statemnt must be testable Term How is a hypothesis usually formulated (If….) Definition if.. then statements hypothesis formulation--->testing---> not falsified=one possible explanation falsified-garbage Term Can the facts change in science? Definition facts in science are never final...what is accepted as a fact today may be modified or even discarded Term Why does it take a lot of time and evidence to show that a scientific theory is false? Definition proof-the idea of proof leaves no room for certainty-gradation scale and the theory is very established Term What's a supernova? Definition the catastrophic , explosive death of a sar accompanied by the sudden, transient brightening of the star to an optical luminosity comparable to that of an entire galaxy Term what are the two different source regions for comets? Definition 1.)Oort Cloud (30-50 AU's) 2.)Kuiper Belt(50000 -100000 AUS) Term What role do stars play in making elements? Definition fusion-fuse together elements Term Explain how our solar system was formed Definition originally big bang made into Rockey (mercury, venus, ceres, erath , marth gaseous (jupiter, satrun , uranus, neptune) rocky and icy(pluto and eris) EXPANSION Term how was the moon formed Definition soon after the earth was forms, a small protoplanet about the size of mars collides with it blasting out debris that forms=moon forms from the ring of debris Term What's peculiar about the orbit of Pluto? Definition all planets orbit roughly with in a single plane (trans neptunian objects) Term What’s a dwarf planet? Definition Ceres, Eris, Pluto a celestial body that orbits teh sun and large enough to assume a nearly round shape, but that does not clear the neighborhood around its orbit and is not a satellite planet Term How are comets and meteor showers related? Definition meteor particle of dust or small chunk of debris meteroid-burning up in the erath's atmosphere leaving a streak of light a great number of meteors that seem to come from one region of the sky within a relatively short period of time METEOR SHOWERS OCCUR WHEN THE EARTH PASSES THROUGH THE DEBRIS TRAIL OF A COMET'S ORBIT Term What’s the difference between a meteoroid, meteor, and meteorite? Definition meteor-a bright trail or streak that appears in the sky when a meteroid is heated to incadescence by fricition by earth's atmosphere meteroid-a solid body moving space that is smaller than an asteroid and at least as large as a speck of dust metorite- a stony or metallic mass of matter that has fallen to the earth's surface from outer space. Term how many officially recognized planets are there? Definition eight Term How is the Earth's magnetic field generated? Definition outer core around the inner core-dynamo! Term Name all the layers of the Earth and their states (solid vs. liquid) Definition solid crust solid-lithosphere solid upper mantle lower mantle-solid liquid outercore solid innercore Term What are the four major forms of evidence that are used to reconstruct the interior of the Earth? Definition seismic analysis digging geochemistry of xenoliths and lava examine meteorites recreate in the lab Term What did the "wrinkled apple model" try to explain about the Earth? Definition molten earth---cooling-- cool exterior and hot center-makes teh surface wrinkled ---makes oceans and mountains Term What are the five major pieces of evidence cited by Alfred Wegener in support of continental drift? Definition 1.fit of the continents 2.distribution of glacial deposits 3.distribution of mountain belts and rocks 4.distribution of fossils 5.distribution of climatic zones Term What is pelagic sediment? Definition a mixture of very fine grained sediment consisting of the microscopic shells of plankton and particle of organic matter Term Why was Wegener's theory met with such great skepticism? Definition he was just a biologist and did not have a geological past Term Explain Arthur Holmes' Convection Current Hypothesis Definition Initially is was proposed that the slowly convecting asthenosphere drags the overlying lithosphere along like a conveyor belts Aurthur Holmes' Convection Current Hypothesis fails to be sufficient to explain observed plate motions -it is impossible to construct a owrking ,global arrangement of convection cells that is consistent with observed plate motions -direction of plate motion does not always coincide with the direction of convetion in the asthenosphere Term Explain the five major sources of new evidence that finally lead to the acceptance of plate tectonics? Definition ss Term How is the lack of a thick blanket of sediment on the floor of the Atlantic evidence that the ocean has not always existed? Definition There were some regions that lacked pelagic sediments Indeed, it was the Mid-oceanic ridges that were virtually without sediment In other words, ocean basins like continents had soon formed after the formation of hte earth and had existed since then in their present form and position. it the atlantic had existed for the entirety of earth's history, then it would be entirely covered by a thick blanked of pelagic sediment this is not so-the atlantic had no always existed==== continents and ocean basin have always been there ocean basins 3.8 billion years-river dumb things into sediment-core the ocean floor, thickest sediment stack-1 at some point in the past and no sediment for years or ocean basins were no 3.8 billions years old-oceans were much younger Term What is meant by a "magnetic reversal", a "magnetic anomaly"? Definition A reversal of the polarity of the earth's magnetic field that has occurred at about one-million-year intervals. Term What parts of the upper mantle are involved in actual plate motion? Definition asthenosphere and lithosphere Term Which two forces drive plate motion and subduction? Definition force-slab/pull Term What happens to subducted slabs? Definition there is much seismic evidence to suggest that subducted slabs are not completely destroyed initially, but are recycled into the lower mantle Term Name the three different types of plate boundaries Definition convergent divergent transform Term Explain how a continental rift forms into an ocean basin Definition continents can break up and a previous continental collisions-ie-india is putting them together convection cell in the mantle zone of heat and split the continent apart- make a rift and ocean comes in eastern part of Africa Term What is a passive margin? Definition a continental margin formed by rifting during continental break up Term What is an accretionary wedge and how does it form? Definition a wedge like shaped of sediment on a continent where subducting goes into the mantle, the slab descends, slab is made of lithospheric mantle, oceanic crust, thin layer of pelagic sediment-as it scrapes against the continent-loosely wedge shape giant bulldozer-accreting sediment onto the edge of the continent Term What is a forearc basin? Definition between the accretionary wedge and the mountains-fills with sediment. A forearc is a depression in the sea floor located between a subduction zone and an associated volcanic arc. It is typically filled with sediments from the adjacent landmass and the island arc in addition to trapped oceanic crustal material Term Draw a cross-section through a typical continental-oceanic subduction zone Definition dd Term Draw a cross-section through a typical rift valley Definition dd Term What is the cause of mineral cleavage? Definition Cleavage is the tendency of a mineral to break along smooth planes parallel to zones of weak bonding. Term What is a conchoidal fracture? Definition Conchoidal fracture describes the way that brittle materials break when they do not follow any natural planes of separation.--a rippling effectb Term Define mineral Definition is a naturally occurring substance formed through geological processes that has a characteristic chemical composition, a highly ordered atomic structure and specific physical properties. Term Name the properties by which minerals can be differentiated from one another What's the difference between a stone and a rock? Definition Term What's the difference between cemented and interlocking grains? Definition cemented grains are glued while interlocking are like a jigsaw puzzle locked next to one another Term What is the difference between lava and magma? Definition lava-molten rock expelled by a volcano during an eruption-liquid at temp from 700 to 1200 degrees -quite viscous magma is molten rock located beneath the surface of the earth that often collects in the magma chamber Term Explain the three means by which melting is caused in the mantle Definition flux decompression heat transfer Term At what temperatures do rocks melt at the surface? Definition 650-1150 degrees celsius Term How does temperature and pressure matter in melting mantle rocks? Definition increase temperature or decrease pressure to melt rocks Term Explain the four different ways in which the composition of a magma can change Definition fractional crystallization-partial melting contamination-all of the magma comes from the same place Term What's the difference between a laccolith and a sill? Definition Laccolith-igneous intrusion or concordant pluton that has been injected between two layers of sedimentary rock sill is a tabular mass of igneous rock that has been intruded laterally between layers of older rock Term What are the two main characteristics that are used to classify crystalline igneous rocks Definition 1.silicic composition 2. grains Term What are the three major types of intrusive igneous rocks and how does their silica content differ? Definition granite=66-78 diorite= 52-66 gabbro=45-52 Term What does mafic mean? Definition in geology, mafic minerals and rocks are silicate minerals, magmas, and volcanic and intrusive igneous rocks that have relatively high concentrations of the heavier elements Term What are the three main products of volcanic eruptions Definition lava flow pyroclastic debris volcanic gas Term How does the composition of a melt influence the shape of a volcano? Definition more silica-steeper-coned little silica-will give it a wide look-shield Term Explain three different forms (shapes…etc.) that lava can take at the surface Definition pahoehoe flows-ropy aa flows-rubbly flow with jumbled angular pieces pillows-blob like shaped pieces of lava formed under Term Name some different types of pyroclastic debris Definition ash powder syzed glassy debris bombs-piece of cooling lava that became streamlined as it traveled through the air pyroclastic flows-fast moving avalanche of hot gas ash and pyroclastic debris also known as nuee ardente or glowing cloud Term What are the three different types of volcanoes and how are they related to the kind of lava that they produce? Definition shield volcanos-broad gently sloped cdones -thin lava flow, low viscocity effusive lava flows cinder cones-steep sloped piles of volcanic debris and some lava flows-thin lava flow and intermediate viscocity-very explosive at vent and effusive lava flows stratovolcano-very large cone shaped mountian thick dome flow and pyroclastic eruptions Term What is the difference between modern uniformitarianism and Lyellian uniformitarianism Definition Modern uniformitarianism---invariance of physical laws of the universe physical process unchanged Lyell-cumulative slow change produced by natural processes operating at relatively constant rate- the present is the key to the past Term How does cement form between sand grains? Definition it is precipitated and glues them together Term What are the three primary means by which sediment is moved across the surface of the planet Definition wind water ice Term What are the sedimentary characteristics of rocks that were deposited in a lacustrine setting? Definition regarding a lake channels ripple marks mudcracks raindrop impressions tool marks terrestrial and freshwater fossils gravel, sand, and silt deposits muds and coals Term What is a crossbed? Definition sedimentary layers-wedges Term What are the sedimentary characteristics of rocks that were deposited in an eolian setting? Definition regarding winds frosted grains well sorted grains large crossbeds terrestrial trace fossils evaporites Term How does a tool mark form? Definition from fluvial environments-such as a log scraping on the bottom of a lake Term What are the sedimentary characteristics of rocks that were deposited in a fluvial setting? Definition channels-ripple marks mudcracks raindrop impressions tool marks terrestrial and freshwater fossils gravel, sandand silt deposits muds an coal Term What are the sedimentary characteristics of rocks that were deposited in a fluvial setting? Definition What are the sedimentary characteristics of rocks that were deposited in a fluvial setting? Term What is Neo-Catastrophism? Definition neo catastrophism =-sudden high magnitude events are a part of geological history both gradual processes and sudden events are important there is room for catastrophe in geology-volcanic eruption, sudden burial, large regional floods, asteroid impact Term How do varves form? Definition a varve is an annual layer of sediment or sedimentary rock varve form from marine and lacustrine depostitional environments from seasonal variation in clasitc, biological, and chemical sedimentary processes. Term life Definition