MSCI 112- Final Exam Review

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At a hot spot, heat causes melting of a small portion of the ______________, which then erupts to Earth's surface.
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Terms in this set (54)
Why does the presence of fossils of the reptile Mesosaurus only in South America and Africa support a previous connection between the two continents about 300 million years ago?
A.) All are correct
B.)Evolution would cause the development of different species (and different fossils) for later times, consistent with observations.
C.) None are correct
D.)Mesosaurus was a fresh water organism and could not have travelled across an ocean between continents.
What was the major shortcoming of Wegener's hypothesis of continental drift?He suggested that tidal forces caused the motions of the continents but this was proved to be impossible.Which is the densest layer of the Earth?CoreThe lithosphere is made up of which compositional layers?Crust and mantleThe magnetic time scale is:A detailed history of Earth's magnetic field reversals. Used in determining rates of plate motion. Used in determining ages of ocean floor rock.Which statement correctly relates plate boundaries to associated changes in plate area?convergent - area decreases divergent - area increases transform - area is unchangedWhat is the name of the ancient ocean that surrounded Pangaea?PanthalassaWhich statement best describes the geometry and geographic distribution of the North American plate?It ranges from the Pacific Coast to the center of the Atlantic Ocean.If there were no convergent plate boundaries, and only spreading centers at mid-ocean ridges were present on Earth, what would happen to our planet?It would expandThe principle of uniformitarianism is summarized as:The present is key to the pastThe current, most generally accepted idea of mantle convection is:Full mantle convection cellsAt a continent-ocean convergent boundary, the _________ plate will subduct, because it is ______________.oceanic, more denseThe asthenosphere is made up of which compositional layers?mantlePlate movement is parallel to:oceanic transform faultsWhich layer(s) of the Earth are mainly made up of silicon and oxygen?Crust and mantleLines on a map of the seafloor that connect rocks of the same age are calledisochronsWhy is the inner core frozen solid whereas the outer core is liquid?Pressure is higher in the inner coreAt approximately which time period did scientists begin to note observations such as coastline shapes that could be explained if the Americas and Europe had been part of a larger continent?about 1600Which of the following statements comparing rates of plate motion determined from seafloor magnetic anomalies and the global positioning system (GPS) is correct?Rates of plate motions over the past decade are very similar to rates over the past several million years.A mineral is usually inorganic; which of the following can be considered a mineral?calcite formed from shells of oystersWhich of the following is NOT an example of a silicate mineral structure?Triple chainIf a geologist wants to determine whether an igneous rock sample cooled within Earth or on its surface after an eruption, what property or feature would the geologist want to examine?TextureWhich class of rock-forming minerals is the most common in Earth's crust?SilicatesWhich of the following minerals would you NOT expect to find in an igneous rock?CalciteTrue or false: Pyroxene and amphibole have the same chemical composition.FalseWhich of the following subatomic particles does NOT have an atomic mass equal to one?ElectronWhich of the following minerals is commonly found only in metamorphic rocks?StauroliteWhat is a vein deposit of an economically important mineral?a sheetlike deposit of minerals precipitated from rapidly cooling hydrothermal solutionsIn the general theory of plate tectonics, at which particular settings do igneous rocks form?Divergent boundaries, convergent boundaries, and hot spotsThe process of magmatic differentiation explains how:rocks of varying composition can arise from the same parent magma.At which type of plate boundary would you expect fluid-induced melting associated with addition of water to rock to be most important?Most magmas form at what types of plate boundaries?Subduction zones and mid-ocean ridgesWhat is the effect of water on rock melting?Water decreases the melting temperature of a rock.Igneous rocks with crystals too small to be seen without a microscope are:fine grained.What happens to temperature with increasing depth in the Earth?Temperature increases faster with depth where Earth's crust is being stretched.An igneous intrusion whose boundaries lie parallel to the layering in the surrounding country rock is considered to be:concordant.The most plentiful minerals in peridotite are:pyroxene and olivineWhat does the viscosity of a liquid measure?the resistance of a liquid to flowAn igneous rock was formed with 8000 radioactive (parent) atoms but contains only 1000 radioactive (parent) atoms today. If the half-life for the radioactive element is 10 million years, the rock is ___ million years old.30The pressure on sediment that is buried to a depth of 4 km is approximately ___ times atmospheric pressure.1000What does the isotopic age of a rock measure (in other words, when does the isotopic clock start)?the time since a sedimentary rock first formedWhat is chemical stratigraphy?mapping of changes in chemical composition of sediments based on age that helps to match sedimentary rocks in different locationsDinosaurs lived during which era of geologic time?MesozoicWhich of the following is a clastic sedimentary environment?What type of event might lead to the development of an unconformity?Sea level drops