1.
Coquina
Correct Answer
C. Sedimentary Rock
Explanation
Coquina is a type of sedimentary rock. It is formed from the accumulation of shell fragments and other organic materials. Over time, these materials are compacted and cemented together to form a solid rock. Coquina is typically found in coastal areas and is known for its porous and lightweight nature. Its classification as a sedimentary rock is based on its origin and formation process.
2.
Basalt
Correct Answer
A. Igneous Rock
Explanation
Basalt is an igneous rock formed from the solidification of molten lava. It is typically dark in color and has a fine-grained texture. Igneous rocks are formed through the cooling and solidification of magma or lava, making them the correct category for basalt. Metamorphic rocks are formed from the transformation of existing rocks due to heat and pressure, while sedimentary rocks are formed from the accumulation and compaction of sediments. Therefore, neither metamorphic nor sedimentary rock categories apply to basalt.
3.
What type of rock is this?
Correct Answer
C. Sedimentary Rock
Explanation
Sedimentary rocks are formed from the accumulation and compaction of sediments over time. These sediments can include fragments of other rocks, minerals, and organic materials. The process of sedimentation involves the deposition of these materials in layers, which then undergo lithification to form solid sedimentary rocks. This type of rock often contains fossils and provides valuable information about Earth's history. Therefore, if someone prefers sedimentary rock, it suggests that they appreciate the processes of deposition, compaction, and lithification that lead to the formation of these rocks, as well as the insights they provide into Earth's past.
4.
Fossiliferous Limestone
Correct Answer
C. Sedimentary Rock
Explanation
Fossiliferous limestone is a type of sedimentary rock formed from the accumulation of calcium carbonate and the remains of marine organisms. The presence of fossils within the rock indicates its sedimentary origin, as fossils are typically preserved in layers of sediment over time.
5.
Gneiss
Correct Answer
B. MetamorpHic Rock
Explanation
Gneiss is a type of metamorphic rock formed from the transformation of pre-existing rocks under high temperature and pressure. It is characterized by its banded appearance and the presence of minerals such as quartz, feldspar, and mica. Gneiss is commonly found in mountainous regions and is often used as a decorative stone in construction due to its attractive patterns and durability.
6.
Granite
Correct Answer
A. Igneous Rock
Explanation
Granite is classified as an igneous rock because it is formed from the solidification of molten magma deep within the Earth's crust. This process involves the cooling and hardening of the magma, resulting in the formation of interlocking mineral crystals that make up the granite. Igneous rocks, including granite, are known for their coarse-grained texture and are commonly found in areas with volcanic activity or as part of the Earth's continental crust.
7.
Rock Salt
Correct Answer
C. Sedimentary Rock
Explanation
Rock salt is a type of sedimentary rock that forms when saltwater evaporates and leaves behind deposits of salt. Sedimentary rocks are formed through the accumulation and solidification of sediments, such as minerals, organic matter, and other particles, over time. Rock salt is a prime example of a sedimentary rock as it is formed from the precipitation of dissolved minerals from seawater.
8.
Marble
Correct Answer
B. MetamorpHic Rock
Explanation
Marble is classified as a metamorphic rock because it is formed from the metamorphism of limestone or dolomite. During the process of metamorphism, the original rock is subjected to high temperatures and pressures, causing the minerals within it to recrystallize and form new structures. This results in the formation of marble, which is characterized by its distinct crystalline structure and smooth texture. Unlike igneous and sedimentary rocks, which are formed through different processes, marble is specifically formed through the metamorphic process. Therefore, the correct answer is metamorphic rock.
9.
Migmatite
Correct Answer
B. MetamorpHic Rock
Explanation
Migmatite is a type of metamorphic rock that forms under conditions of extreme heat and pressure, where partial melting occurs. It displays characteristics of both metamorphic and igneous rocks, often featuring a mixture of metamorphosed minerals and igneous intrusions. It is not classified as an igneous or sedimentary rock.
10.
Obsidian
Correct Answer
A. Igneous Rock
Explanation
Obsidian is a type of volcanic glass that forms from the rapid cooling of lava. It is classified as an igneous rock because it originates from the solidification of molten material. Igneous rocks are formed through the cooling and solidification of magma or lava. This process allows for the formation of unique textures and compositions, such as the smooth and glassy texture of obsidian. Therefore, the correct answer is Igneous Rock.
11.
Pumice
Correct Answer
A. Igneous Rock
Explanation
Pumice is a type of volcanic rock that is formed when lava with high levels of gas and water content erupts from a volcano. As the lava cools rapidly, the gas bubbles are trapped in the rock, giving it a porous and lightweight texture. This process is characteristic of igneous rocks, which are formed from the cooling and solidification of molten material. Therefore, the correct answer is Igneous Rock.
12.
Quartzite
Correct Answer
B. MetamorpHic Rock
Explanation
Quartzite is a metamorphic rock because it is formed from the metamorphism of quartz-rich sandstone. During the metamorphic process, the sandstone is subjected to high heat and pressure, causing the quartz grains to recrystallize and fuse together, resulting in the formation of quartzite. This transformation from sedimentary rock to metamorphic rock is a characteristic feature of quartzite, making it the correct answer.
13.
Rhyolite
Correct Answer
A. Igneous Rock
Explanation
Rhyolite is a type of igneous rock that is formed from volcanic activity. It is characterized by its high silica content and fine-grained texture. Igneous rocks are formed when molten rock, or magma, cools and solidifies. Rhyolite is typically found in volcanic areas and is often associated with explosive eruptions. It is not a metamorphic or sedimentary rock, as it does not undergo the same processes of heat and pressure that these rock types experience. Therefore, the correct answer is Igneous Rock.
14.
Sandstone
Correct Answer
C. Sedimentary Rock
Explanation
Sandstone is a type of rock that is formed from the accumulation and cementation of sand grains. It is composed mostly of sand-sized grains of mineral, rock, or organic material. This process of formation is characteristic of sedimentary rocks, which are formed from the deposition and lithification of sediments. Therefore, sandstone is classified as a sedimentary rock.