Q&A Hero

Q: Which of the following is not a process than can cause metamorphism? A) heating B) solidification of magma C) pressure D) compression and shear

Q: A rock transformed from any other rock through extreme heat and or pressure is referred to as A) sedimentary. B) metamorphic. C) igneous. D) ancient.

Q: The presence of 180-million-year-old salt domes in the Gulf Coast region of the United States indicates that A) the area was once volcanically active. B) the area was subjected to plate collisions which caused metamorphism to occur. C) subsidence is now occurring due to the withdrawal of magma from the region. D) a sea used to cover the area but subsequently evaporated.

Q: If you were driving down the highway and saw mountains composed of layered strata, you could be confident that you were looking at A) sedimentary rocks. B) extrusive igneous rock. C) a shield volcano. D) batholiths or laccoliths.

Q: Travertine, formed from the CaCO3that has been precipated from groundwater, is an example of ________ sedimentary rock. A) clastic B) biochemical C) organic D) chemical

Q: Limestone formed from the shells of marine organisms is an example of ________ sedimentary rock. A) clastic B) biochemical C) organic D) chemical

Q: Sedimentary rock formed from dissolved minerals that precipitate out of water solution and build up to form rock are A) clastic. B) inorganic. C) organic. D) chemical.

Q: Which of the following lists, in proper sequential order, the steps leading to the formation of clastic sedimentary rock? A) erosion, transportation, deposition, cementation B) erosion, deposition, transportation, cementation C) erosion, transportation, deposition, metamorphism D) precipitation, settling, compaction, cementation

Q: Sedimentary rock formed from the combined processes of weathering, erosion, transportation, deposition, lithication, and compaction of rock fragments of other rocks are A) clastic. B) biochemical. C) organic. D) chemical.

Q: What type of rock is derived from the bits and pieces of former rocks? A) sedimentary B) metamorphic C) igneous D) hydrothermal

Q: Small plutons that form parallel to layers of sedimentary rock are known as A) dikes. B) laccoliths. C) sills. D) batholiths.

Q: A batholith forms from A) intrusive igneous rock. B) extrusive igneous rock. C) metamorphic rock. D) sediment accumulation in a depression.

Q: Which of the following is an example of an intrusive, igneous rock formation? A) volcano B) pluton C) dome D) lava flow

Q: Mafic igneous rock, such as gabbro and basalt, A) are derived from magnesium and iron. B) have light coloration. C) are high in silicate minerals. D) have a low melting temperature.

Q: Felsic igneous rock, such as granite and rhyolite, A) have dark coloration. B) are not resistant to weathering. C) have a high melting temperature. D) are high in silicate minerals.

Q: Obsidian is an igenous rock with a glassy appearance and minimal crystal growth. What accounts for this? A) Obsidian is an intrusive igneous rock that cooled slowly beneath the Earth's surface, result in little crystal growth. B) Obsidian is an extrusive igneous rock that cooled slowly on the Earth surface, resulting in little crystal growth. C) Obsidian is an extrusive igneous rock that cooled very slowly on the Earth surface, resulting in little crystal growth. D) Obsidian is an intrusive igneous rock that cooled rapidly beneath the Earth's surface, result in little crystal growth.

Q: Extrusive igeneous cooled and hardened ________ the Earth's surface, resulting in ________ grained rocks. A) beneath; finer B) beneath; coarser C) at; finer D) at; coarser

Q: Intrusive igeneous cooled and hardened ________ the Earth's surface, resulting in ________ grained rocks. A) beneath; finer B) beneath; coarser C) at; finer D) at; coarser

Q: Which rock type makes up approximately 90% of the Earth's crust. A) sedimentary B) metamorphic C) igneous

Q: Molten rock beneath the Earth's surface is known as ________, whereas molten rock on the Earth's surface is called ________. A) lava; magma B) intrusive; extrusive C) magma; lava D) extrusive; intrusive

Q: What type of rock forms from the solidification of molten material? A) sedimentary B) metamorphic C) igneous

Q: The major rocks of Earth's crust are classified into principal types based on A) element composition. B) mineral composition. C) three specific rock-forming processes; i.e., the manner in which they formed. D) relative and absolute locations.

Q: The three basic rock types are A) conglomerates, clastics, and evaporative. B) intrusive, extrusive, and plutonic. C) laterite, schist, and basalt. D) sedimentary, metamorphic, and igeneous.

Q: An assemblage of minerals bound together is called a A) granitic compound. B) mineral. C) molecule. D) rock.

Q: Approximately 95% of the Earth's crust is made up of A) oxides. B) phosphates. C) silicates. D) carbonates.

Q: Which of the following is not a criteria to be classified as a mineral? A) inorganic B) anthropogenic C) solid D) definable chemical composition E) crystalline structure

Q: An element or combination of elements that forms an inorganic, natural compound is called a A) tectonic rock. B) granitic compound. C) mineral. D) molecule.

Q: The three most abundant elements in Earth's crust are A) rock, water, and tectonics. B) magnesium, potassium, and oxygen. C) iron, aluminum, and granite. D) oxygen, silicon, and aluminum.

Q: Continental crust is basically ________, whereas oceanic crust is basically ________. A) thin; thick B) basalt; granite C) granite; basalt D) sima; sial

Q: The transition zone from the upper mantle to the crust is known as the ________ discontinuity. A) Gutenberg B) Mohorovičić C) Asthensosphere D) Lithosphere

Q: The majority of the Earth's volume is within the A) crust. B) inner core. C) mantle. D) outer core.

Q: The uneven transition zone from the outer core to the mantle is known as the ________ discontinuity. A) Gutenberg B) Mohorovičić C) Asthensosphere D) Lithosphere

Q: The majority of Earth's crust is composed of ________ rock. A) igneous B) metamorphic C) sedimentary D) carbonate

Q: The last pole reversal occurred ________ years ago and, based on magnetic field decay, we are approximately ________ years from entering the next phase. A) 1 million; 200,000 B) 20,0000; 50,000 C) 1,000; 50 D) 790,000; 1,000

Q: The average length of a period during which a given magnetic field polarity exists is about A) 10,000 years. B) 100,000 years. C) 500,000 years. D) 1,000,000 years.

Q: Earth's magnetic field A) is variable, and it has faded to zero and returned to full strength with the polarity reversed. B) is constant in its intensity. C) remains a mystery as to its cause. D) is principally generated in the inner core.

Q: Which of the following layers of Earth is liquid and is responsible for producing Earth's magnetic field? A) inner core B) outer core C) lower mantle D) aesthenosphere

Q: During the past ice age, landmasses were generally A) pressed down into the asthenosphere by the load of ice. B) elevated, because ice is lighter than rock. C) unaffected by the climatic conditions of the time. D) more exposed to the atmosphere.

Q: Glaciers that once covered the Hudson Bay area melted 8,000 years ago. As a result of this, the bay is gradually rising. In another 10,000 years or so, it will have risen above sea level and become dry. This process can best be considered an example of A) catastrophism. B) isostasy. C) accretion. D) orogenesis.

Q: The process of isostatic adjustment is most closely associated with which of the following? A) lithospheric plate collisions B) volcanic activity C) sea-floor spreading D) buoyancy

Q: The principles of buoyancy and balance, when applied to Earth's crust, helps us to explain fluctuations in Earth's outer crust, a property known as A) magnetism. B) Moho effect. C) isostasy. D) orogenesis.

Q: The rigid crust and uppermost mantle are known collectively as the A) asthenosphere. B) lithosphere. C) Moho. D) Gutenberg discontinuity.

Q: The plastic layer in the mantle from about 70 to 250 km (43 to 155 mi) in depth is known as the A) asthenosphere. B) lithosphere. C) Moho. D) Gutenberg discontinuity.

Q: The aesthenosphere can best be described as A) a rigid solid. B) a liquid. C) a plastic. D) a plasma.

Q: The thickness of Earth's crust ranges from A) 5 km to 60 km (3 mi. to 37 mi.). B) 70 km to 250 km (43 mi. to 155 mi.). C) the surface to an unknown depth. D) the surface down to 2900 km (1800 mi.).

Q: The dominant element in oceanic crust are A) silica and aluminum. B) silica and magnesium. C) magnesium and aluminum. D) potassium and iron.

Q: The dominant element in continental crust are A) silica and aluminum. B) silica and magnesium. C) magnesium and aluminum. D) potassium and iron.

Q: Which of the following is correct? A) Continental crust is less dense than oceanic crust and composed primarily of basalt. B) Continental crust is denser than oceanic crust and composed primarily of granite. C) Oceanic crust is less dense than continental crust and is composed primarily of granite. D) Oceanic crust is denser than continental crust and is composed primarily of basalt.

Q: The percentage of oxygen is the crusts is ________ than that in the atmosphere. A) greater than B) less than C) the same as

Q: Of the elements in the Earth's crusts, ________ makes up the most of the Earth's crust by weight. A) silicon (Si) B) aluminum (Al) C) oxygen (O) D) iron (Fe)

Q: On average, the thickness of oceanic crust is ________ that of continental crust A) greater than B) less than C) the same as

Q: The density of material below the Moho is ________ that above it. A) greater than B) less than C) the same as

Q: The boundary between the crust and the rest of the lithospheric upper mantle is a discontinuity known as the A) Gutenberg. B) mantle. C) Moho. D) lithospheric layer.

Q: Which layer of the planet forms 80 percent of Earth's total volume, and has an average density of 4.5 grams/cm3? A) continental crust B) oceanic crust C) mantle D) core

Q: Which of the following statements about Earth's core is not correct? A) It is composed primarily of iron. B) The inner core is believed to be liquid and the outer core solid. C) Scientists think the inner core formed before the outer core. D) A third of the Earth's entire mass, but only 1/6th of its volume lies in its core.

Q: Which of the following is incorrect regarding Earth's inner core? A) It has a density of 13.5 grams/cm3. B) It is solid iron in composition. C) It is the source of Earth's magnetic field. D) It is about 1230 km (760 mi.) thick.

Q: Which of the following can occur when seismic waves encounter a layer in Earth's interior? A) reflection and/or refraction B) absorption C) change in speed D) reflection, refraction, absorption, and change in speed. E) seismic waves cannot penetrate below the crust of Earth

Q: Which of the following gives the correct sequence of layers in Earth, from the surface to the center? A) crust, inner core, mantle, outer core B) inner core, outer core, mantle, crust C) mantle, crust, inner core, outer core D) crust, mantle, outer core, inner core

Q: Earth's interior is layered because A) centrifugal force separated out the materials based on weight as the Earth solidified. B) materials became sorted based on density as the Earth solidified. C) materials became sorted based on electromagnetic fields as the Earth solidified.

Q: The fact that Earth's interior is sorted into layers indicates that A) the process of formation from a nebula (by the slamming together of material and planetesimals that stuck together on impact) produces nice, neat layers. B) Earth was once in a molten state, during which materials became sorted based on density. C) the rotation of the early Earth acted like a centrifuge which separated materials based on weight. D) nothing can be inferred about such a perplexing level of organization.

Q: Knowledge of Earth's interior is mostly derived from A) direct sampling of the interior using deep-test wells. B) work in Earth's deepest caverns and caves. C) indirect evidence involving the analysis of seismic waves. D) historic and prehistoric records.

Q: Scientists have direct evidence of the Earth's structure to A) the inner core. B) the upper mantle (~250 km (155 mi)). C) about 2 km (1.2 mi) from the surface. D) 10 km (6 mi) from the surface, based on the deepest well shaft.

Q: In terms of dating of specific rocks, structures, or landscapes, numerical age refers to A) the age of geological features based on isotopic dating techniques. B) the approximate age of geological features based on the period or epoch in which they occurred. For instance, noting a feature is from the Cretaceous. C) a range of numeric values in which a features was likely formed and based on several lines of evidence, such as paleoclimatic and paleobotanical reconstructions. D) the age of one feature with respect to another within a sequence of events and deduced from the positions of rock strata above and below one another.

Q: In terms of dating of specific rocks, structures, or landscapes, relative age refers to A) the age of geological features based on isotopic dating techniques. B) the approximate age of geological features based on the period or epoch in which they occurred. For instance, noting a feature is from the Cretaceous. C) the inability to ascertain exact age through isotopic methods and the necessity to provide a date range for such features. D) the age of one feature with respect to another within a sequence of events and deduced from the positions of rock strata above and below one another.

Q: Which of the following is correct in regards to the geologic time scale? A) An epoch is composed of one or more periods. B) The largest defined unit is an eon or, according to some, a supereon. C) An era is the smallest unit of geologic time. D) Every period is composed of 2 epochs.

Q: The scientific study of rock strata (layers) is known as ________ and based on the principle of ________. A) stratigraphy; superposition B) geomorpholy; uniformitarianism C) Paleontology; catostrophism D) Paleogeography; plate tectonics

Q: Which of the following is not an example of an age-relationship based on absolute dating? A) The oldest known rocks on Earth are 3.96 billion years old. B) The Vishnu schist at the bottom of the Grand Canyon is 2 billion years old. C) The dinosaurs became extinct 65 million years ago. D) The Coconino formation in the Grand Canyon is older than the Kaibab formation.

Q: Which of the following is an example of an age-relationship based on relative dating? A) Australopithecines were alive 3.2 million years ago. B) The Neanderthals became extinct 35,000 years ago. C) Australopithecines evolved before Homo erectus. D) Clovis points have been dated at 11,000 years old in North America.

Q: Boundaries between intervals of the geological time scale are determined by A) dividing the time range of the interval by the number desired subdivisions, thereby creating equal intervals between the divisions. B) Major events in the Earth's history, such as major extinctions. C) using a quantile method whereby the number of years in each subdivision is determined by dividing the number of years by the desired number of classes. D) Climatic periods based on paleoclimatological reconstructions.

Q: The Precambrian Eon encompasses what percentage of Earth's total history? A) 0.04 % B) 5% C) 11.7% D) 88.3%

Q: Which of the following is correct regarding the geologic time scale? A) The Jurassic period occurred during the Paleozoic era. B) Over 87 percent of Earth's history has elapsed during the more recent Cenozoic, Mesozoic, and Paleozoic eras. C) The bulk of Earth's history has occurred during the Precambrian eon. D) We live in the Tertiary period.

Q: When geologists conclude that the Grand Canyon sequence of rocks was formed through hundreds of millions of years of deposition, mountain building, and erosion, they are basing this conclusion on the principle of ________ which states that ________. A) catastrophism; most rock formations were created as a result of supernatural processes B) catastrophism; a single, large flood was responsible for the creation of the rock sequence C) uniformitarianism; all geologic processes take immense amounts of time to occur and always occur at the same rate D) uniformitarianism; the geologic processes that operated in the past are the same as those that operate today, and they occurred in accordance with the same laws of nature that are operating today

Q: Which of the following is an example of the principle of uniformitarianism? A) It is not possible to know how Earth processes have changed overtime, therefore it is not possible to deduce how Earth's ancient landforms evolved. B) The processes by which streams carve valleys at present are the same as those that carved valleys 500 millions years ago. C) Catastrophic events, such as major landslides, earthquakes, and volcanic episodes, are the primary drivers of geomorphological change. D) The Earth's geological history is mostly uniform and homogenous, existing now as it mostly always has with the exception of minor recent changes.

Q: Uniformitarianism assumes that A) Earth is quite young and is shaped by dramatic events. B) catastrophic episodes have regularly occurred. C) the same physical processes we see today are a key to understanding the processes that have been operating throughout geologic time. D) mountains, plains, and canyons formed by catastrophic events.

Q: The principle that the same physical processes currently active in the environment were operating throughout Earth's history is known as A) uniformitarianism. B) catastrophism. C) parallelism. D) statis.

Q: Earth's magnetic poles A) are fixed. B) are migrating approximately 55 to 60 km (34 to 37 mi) per year. C) are perfectly aligned with Earth's axis. D) are misaligned from Earth's axis by 23.5 degrees.

Q: Tectonic forces are an example of A) exogenic processes. B) endogenic processes. C) both exogenic and endogenic processes. D) neither exogenic nor endogenic processes.

Q: Which of the following plays a role in the shaping of Earth's surface? A) gravity B) the action of wind, water, and ice C) the radioactive decay of atoms D) gravity, wind, water, and ice, and radioactive decay E) gravity and wind, water, and ice only

Q: Which of the following is an exogenic process? A) earthquakes B) volcanism C) flows of heat and materials in the mantle D) weathering

Q: Which of the following is an endogenic process? A) weathering B) stream deposition C) volcanism D) glacial erosion