Q&A Hero

Q: The type of fossilization that occurs when the remains of an organism are replaced by mineral matter is called A) carbonization. B) replacement. C) an impression. D) a cast.

Q: Sediments convert to rock when they undergo A) compaction and cementation. B) lithification. C) both A and B.

Q: Ice wedgingfreezing of water in cracksis an example of A) chemical weathering. B) mechanical weathering. C) iron oxide stain. D) lithification.

Q: Carbonate deposition occurs in environments that are A) warm and humid. B) cool and wet. C) monsoonal. D) dry as deserts.

Q: When rock is broken down into smaller and smaller pieces, we say the rock has undergone A) chemical weathering. B) mechanical weathering. C) erosion. D) lithification.

Q: Petroleum and oil reserves are often found in sedimentary rocks because A) these rocks are very porous and permeable. B) chemical changes occur to create these reserves. C) these rocks often contain fossilized organic matter. D) oil accumulates in the sediments.

Q: In a wet and humid climate, the mineral halite will succumb to weathering more easily than granite because A) granite is more resistant. B) halite readily dissolves in water. C) halite is relatively soft (hardness of 2.5). D) all of the above.

Q: In a sedimentary rock, small rounded particles indicate a A) long distance and long travel time. B) short distance and short travel time. C) long distance and short travel time. D) short distance and long travel time.

Q: Layers of limestone in a rock outcrop often indicate that the area had at some time been A) near the site of volcanic activity. B) glaciated. C) covered by water. D) a desert area.

Q: The most common carbonate rock is A) dolomite. B) calcite. C) halite. D) limestone.

Q: Sedimentary rocks provide clues about past geologic events and settings. A low energy, quiet environment such as a lagoon or lake bed provides the perfect setting for the formation of A) sandstone and shale. B) shale and evaporites. C) arkose and dolomite. D) none of these

Q: Limestone may be made up of A) fragments of granitic and andesitic rocks. B) animal bones. C) shell fragments from marine animals. D) plant debris.

Q: If the rock particles in a sedimentary rock are relatively small with well sorted and well rounded grains, we can infer that the sediment grains traveled a A) short distance. B) long distance for a long time. C) long distance in a short time. D) short distance for a long time.

Q: As rock is weathered it breaks down and erodes. Sedimentation begins where erosion stops. Erosion is A) disintegration and fragmentation of rock into smaller pieces. B) a chemical process. C) decomposition and alteration of rock material. D) transportation of rock particles via water wind or ice.

Q: Of the following rocks, the one that does not originate in sediments laid down by water, wind, or ice is A) sandstone. B) marble. C) shale. D) conglomerate.

Q: The majority of surface rocks are A) extrusive. B) sedimentary. C) intrusive. D) metamorphic.

Q: The three most common cementing agents in a sedimentary rock are A) silica, calcite, and hematite. B) calcite, silica, and iron oxide. C) silica, carbonate, and feldspar. D) silica, iron oxide, and sandstone.

Q: Some ________ rock is formed from minerals that were once dissolved in water. A) sedimentary B) igneous C) metamorphic D) igneous and metamorphic

Q: How does silica content effect volcanic eruptions?

Q: What is the difference between intrusive and extrusive igneous rocks?

Q: Relate silica content to crystallization from a magma.

Q: What two factors can change a rock's melting point?

Q: Minerals in volcanic rocks are usually smaller than minerals in plutonic rock. Why is this?

Q: What does partial melting have to do with silica content of a magma?

Q: What is partial melting?

Q: As rock melts to become magma, which minerals are the first to melt?

Q: The Earth's temperature increases with depth. Pressure also increases with depth from the weight of the rock above. As pressure increases the A) rock above begins to melt. B) melting point of the rock (at depth) decreases. C) melting point of the rock (at depth) also increases. D) temperature increases, rocks begin to melt.

Q: The most common igneous rock is A) basalt. B) andesite. C) granite. D) none of these

Q: The volcanoes of the Hawaiian Islands are A) strato-volcanoes. B) composed of andesite. C) shield volcanoes. D) cinder cones.

Q: Volcanic rocks form from A) the eruption of viscous magma. B) partial melting of basalt. C) solidification of lava.

Q: Shield volcanoes are composed of A) andesitic magma. B) basaltic magma. C) granitic magma. D) silica-rich magma.

Q: The largest volcano on Earth is a A) shield volcano. B) cinder cone. C) composite cone. D) lava plateau.

Q: Lava can be A) extruded from a volcano. B) a cooled, solid rock. C) intruded as a dike. D) both A and B.

Q: Beautiful cone-shaped volcanoes such as Mt. Fuji, Mt. Hood, and Mt. Rainer are predominantly composed of A) basaltic rocks. B) andesitic rocks. C) granitic rocks.

Q: The largest volumes of magma extruded on the continents are A) flood and plateau basalts. B) central-vent type volcanoes. C) batholiths. D) from volcanoes with a high silica content.

Q: Most of the batholithic-sized plutons found in the continents are composed of A) obsidian. B) basalt. C) granite. D) sandstone.

Q: A composite volcano is formed by A) successive flows of fluid basaltic lava. B) a mixture of rock and lava. C) alternating layers of lava, ash, and mud flow debris. D) the accumulation of ash, cinders, and rock debris.

Q: The silica content of magma greatly affects its viscosity. Magma with a high silica content has a A) high viscosity and flows quickly. B) high viscosity and flows slowly. C) low viscosity and flows quickly. D) low viscosity and flows slowly.

Q: The most violent volcanic explosions are generated from A) basaltic lava flows. B) andesitic lava flows. C) granitic lava flows. D) ocean floor lava flows.

Q: The most violent volcanic explosions are generally associated with A) composite volcanoes. B) cinder cones. C) shield volcanoes. D) none of these

Q: Mauna Loa is a A) cinder cone. B) shield volcano. C) composite volcano. D) none of these

Q: The most common outpouring of lava occurs as A) volcanic eruptions. B) carbonates. C) conglomerates. D) fissure eruptions.

Q: The most common extrusive rocks are generated from A) andesitic magma. B) granitic magma. C) basaltic magma. D) none of the above

Q: Batholiths are massive plutons formed from the intrusion of A) andesitic magma. B) granitic magma. C) basaltic magma. D) all of these

Q: Plutons form from magma A) at Earth's surface. B) below Earth's surface. C) ejected from volcanoes. D) all of these

Q: Igneous rocks are formed by the A) melting and transformation of minerals in Earth's interior. B) cooling and crystallization of molten magma. C) partial crystallization of granitic magma. D) cooling and crystallization of molten lava in Earth's interior.

Q: Rocks with a high water content have a A) higher melting point. B) lower melting point. C) higher pressure. D) lower pressure.

Q: As rock is heated, the first minerals to melt are those A) with the highest melting point. B) with the lowest melting point. C) composed of granitic magma. D) that have undergone partial distillation.

Q: The first minerals to crystallize are those having the A) higher melting point. B) lower melting point. C) higher pressure. D) lower pressure.

Q: The most common igneous rock is formed from A) basaltic magma. B) andesitic magma. C) granitic magma. D) none of these

Q: Basaltic volcanic eruptions tend to be A) slow moving and highly viscous. B) very fluid and highly viscous. C) slow moving with a low viscosity. D) very fluid and have a low viscosity.

Q: The Hawaiian Islands are predominantly made up of A) intrusive igneous rock. B) volcanic igneous rock. C) sedimentary rock. D) metamorphic rock.

Q: The two most common igneous rocks are basalt and granite. Basalt is commonly found ________, and granite is found ________. A) on the ocean floor; on the continents B) on both the ocean floor and continental land; only on the continents C) on the continents; on the ocean floor D) on the ocean floor; on both the ocean floor and on continental land

Q: Magma that solidifies before reaching Earth's surface is called A) intrusive igneous rock. B) plutonic rock. C) a pluton. D) all of the above.

Q: A rock's initial melting temperature is primarily determined by A) the rocks mineralogy. B) its water content. C) its internal temperature. D) its heat source.

Q: The process by which a single magma can generate several magmas of different compositions is A) partial melting. B) partial crystallization. C) fractional crystallization. D) partial distillation.

Q: The process of crystallization enriches a magma in A) silica. B) minerals that have low melting points. C) silica and other minerals that have low melting points. D) all of the above.

Q: Igneous rock is formed from A) crystallization of molten magma. B) high temperatures and pressures. C) solidified lava beneath the Earth's surface. D) any of these

Q: Rocks are grouped into three classes depending on how the rock was A) formed. B) located. C) discovered. D) shaped.

Q: A sedimentary rock can turn into an igneous rock by A) compaction and cementation. B) compaction. C) melting and cooling. D) weathering and lithification.

Q: The melting point of silicate minerals is strongly dependent on the amount of silica they contain. Generally speaking, which minerals are the first to melt?

Q: In a cooling magma, which minerals are the last to crystallize?

Q: In a cooling magma, which minerals are the first to crystallize?

Q: As the process of crystallization continues (from molten liquid to solid crystal), how does the composition of the molten liquid change?

Q: Which mineral, quartz or feldspar, will crystallize first? Why?

Q: Which minerals are the first to crystallize in a cooling magmaminerals with a lower percentage of silica or minerals with a higher percentage of silica?

Q: Describe two sources from which minerals can crystallize.

Q: Describe the process of crystallization.

Q: Silica has a relatively A) low percentage of silicon. B) high percentage of silicon.

Q: Silica has a relatively A) low melting point. B) high melting point.

Q: For the crystallization of minerals from a magma, melting point determines which mineral will form first. For evaporite minerals A) solubility determines which mineral will form first. B) salinity determines which mineral will form first. C) melting point also determines which mineral will form first. D) there is no single determinant. All evaporite minerals precipitate at the same time.

Q: The precipitation of and crystallization of evaporite minerals is very similar to the crystallization of minerals from a magma. The first evaporite minerals to precipitate (crystallize) are those with the A) lowest solubility. B) highest melting point. C) lowest silica content. D) highest solubility.

Q: As the process of crystallization continues (from molten liquid to solid crystal) the composition of the molten liquid becomes A) depleted in the minerals that have already crystallized. B) enriched in the minerals that have already crystallized. C) depleted in the minerals that have yet to crystallize. D) enriched in the minerals that have yet to crystallize. E) both A and D F) both B and C

Q: The last minerals to crystallize from a cooling magma have a A) high melting point and a low silica content. B) low melting point and a high silica content. C) high melting point and a high silica content. D) low melting point and a low silica content.

Q: The first minerals to crystallize from a cooling magma have a A) high melting point and a low silica content. B) low melting point and a high silica content. C) high melting point and a high silica content. D) low melting point and a low silica content.

Q: Minerals are formed by the process of A) crystallization. B) magma differentiation. C) silica enrichment. D) partial melting.

Q: The last minerals to crystallize are those with the A) higher melting point. B) lower melting point.

Q: The first minerals to crystallize are those with the A) higher melting point. B) lower melting point.

Q: Chemical sedimentary rocks are formed from A) biochemical interactions. B) carbonization. C) the precipitation of minerals from a water solution. D) evaporites.

Q: Similar to the crystallization of silicate minerals, the crystallization of evaporite minerals occurs in a step-by-step process. The evaporite minerals that are the most difficult to dissolve A) precipitate last. B) precipitate first followed by the minerals that dissolve more easily. C) have the lowest solubility and are the last to precipitate. D) have the highest solubility and are the first to precipitate.