Question 1

Of the following rocks, the one that does not originate in sediments laid down by water, wind, or ice is

Accepted Answer

Marble is a metamorphic rock that originates from limestone or dolomite that has undergone extreme heat and pressure, typically deep within the Earth's crust. It does not form from sedimentation by water, wind, or ice. On the other hand, sandstone, shale, and conglomerate are all sedimentary rocks that form from the accumulation and compression of sediments.

Question 2

Petroleum and oil reserves are often found in sedimentary rocks because

Accepted Answer

Petroleum and oil reserves are often found in sedimentary rocks because these rocks can contain fossilized organic matter.

Question 3

If the rock particles in a sedimentary rock are relatively small and if the grains are well sorted and well rounded, we can infer that the sediment grains traveled a

Accepted Answer

The small size, well-sorted nature, and well-rounded shape of sediment grains indicate that they have been transported over a long distance for a long time. This is because the physical weathering and erosion processes, as well as transportation, tend to break down larger particles into smaller ones and smooth out rough edges, leading to sorting and rounding of the grains.

Question 4

The rock that has undergone the greatest extent of metamorphic change is

Accepted Answer

Gneiss is the rock that has undergone the greatest extent of metamorphic change, characterized by its distinct banding and foliation resulting from high-grade metamorphism.

Question 5

The property many metamorphic rocks exhibit by flat or elongated mineral grains in parallel layers is called

Accepted Answer

Foliation is the term used to describe the property of metamorphic rocks where they exhibit flat or elongated mineral grains arranged in parallel layers. This feature is a result of high pressure and temperature conditions that realign the mineral grains during the metamorphic process.

Question 6

Which of the following is not a characteristic of quartz?

Accepted Answer

Quartz is known for its lack of cleavage, meaning it does not break along flat planes. Instead, it fractures conchoidally. The other options (hardness of 7, six-sided crystals, conchoidal fracture, and composition of SiO₂) are accurate characteristics of quartz.

Question 7

The metamorphic equivalent of limestone is

Accepted Answer

Limestone undergoes metamorphism to become marble.

Question 8

The layered appearance of foliated metamorphic rocks is due to the

Accepted Answer

The layered appearance of foliated metamorphic rocks is primarily due to the realignment of minerals in response to compressive forces, causing them to orient perpendicular to the direction of pressure. This process creates the characteristic banded or layered appearance.

Question 9

Some ________ rock is formed from minerals that were once dissolved in water.

Accepted Answer

Sedimentary rocks are formed from the accumulation of sediment and are often made up of minerals that were once dissolved in water, such as limestone and sandstone. Igneous rocks are formed from the solidification of molten lava or magma, and metamorphic rocks are formed from the transformation of existing rocks under heat and pressure. Both of these rock types are not typically formed from dissolved minerals. Therefore, the best choice is A) sedimentary.

Question 10

By definition, an ore is a mineral rich in valuable metals. To be considered as an ore means that the

Accepted Answer

The definition of an ore includes the requirement that the valuable metals can be economically extracted, which means that the cost of extraction is lower than the value of the metals that can be recovered. Simply having a deposit rich in valuable metals does not make it an ore.

Question 11

A foliated metamorphic rock derived from granite is

Accepted Answer

Gneiss is a foliated metamorphic rock that is formed from granite or other igneous rocks through high-grade metamorphism. It has distinctive layers or banding of minerals, which results from the reorganization of the original minerals into new, oriented minerals under high pressure and temperature conditions. Quartzite is a non-foliated metamorphic rock that is formed from sandstone, slate is a foliated metamorphic rock that is formed from shale or clay-rich rocks, and marble is a non-foliated metamorphic rock that is formed from limestone or dolostone.

Question 12

The majority of surface rocks are

Accepted Answer

The majority of surface rocks on Earth are sedimentary. This is because sedimentary rocks form from the accumulation of sediments, such as sand, mud, and small pieces of rock, which are often deposited in layers by water, wind, or ice. Over time, these sediments are compacted and cemented together, forming sedimentary rocks. These processes are very common on the Earth's surface, making sedimentary rocks the most prevalent type of rock found at the surface.

Question 13

The two most common igneous rocks are basalt and granite. Basalt is commonly found ________ and granite is found ________.

Accepted Answer

The answer of The two most common igneous rocks are...

Question 14

Metamorphism caused by the close proximity of a magma source is called

Accepted Answer

Contact metamorphism occurs when rocks are heated by the close proximity of magma, leading to changes in their mineralogy and texture without the rock melting.

Question 15

Magma that solidifies before reaching Earth's surface is called

Accepted Answer

All of the above options are correct. Magma that solidifies before reaching Earth's surface can form intrusive igneous rocks, which are formed when magma cools and solidifies below the surface. Plutonic rocks are another term for intrusive igneous rocks. A pluton is a large igneous intrusion that has been exposed on the Earth's surface through erosion, and it is also a type of intrusive igneous rock.

Question 16

A mineral deposit can be classified as an ore deposit when

Accepted Answer

An ore deposit is classified as such when the valuable metals present in the deposit can be mined at a profit. The presence of valuable metals alone does not classify a deposit as an ore deposit, as it must also be economically feasible to extract them. The other options mentioned - fossil fuels and gemstone minerals - do not fall under the definition of an ore deposit.

Question 17

Limestone may be made up of

Accepted Answer

Limestone is primarily composed of calcium carbonate, which is often derived from the skeletal remains of marine organisms such as corals, mollusks, and foraminifera. As these animals die, their shells and skeletal fragments accumulate on the seafloor and are eventually compacted and cemented into limestone rock.

Question 18

Rocks altered by heat and pressure beneath Earth's surface are

Accepted Answer

Rocks altered by heat and pressure beneath Earth's surface are metamorphic rocks. They are formed when pre-existing rocks are subjected to high temperatures and pressures, causing changes in their mineral composition and texture. Intrusive and extrusive igneous rocks are formed from the cooling and solidification of magma or lava, while sedimentary rocks are formed from the accumulation and consolidation of sediment. None of these processes involve significant heat and pressure alteration like in metamorphic rocks.

Question 19

Because sedimentary rocks are formed at Earth's surface, they provide clues about past geologic events and settings. A low energy, quiet environment such as a lagoon or lake bed provide the perfect setting for the formation of

Accepted Answer

Shale and evaporites form in low energy, quiet environments like lagoons or lake beds because these settings allow for the accumulation of fine-grained sediments and the evaporation of water, leading to the precipitation of minerals. Marble is a metamorphic rock, and basalt is an igneous rock, neither of which form directly from sedimentation in quiet water environments.

Question 20

The most common carbonate rock is

Accepted Answer

Limestone is the most common carbonate rock and is composed mainly of the mineral calcite. Dolomite is another carbonate rock, but it is less common than limestone. Halite is a mineral composed of sodium chloride and is not a carbonate rock.

Quiz 23: Rocks and Minerals