FREE SCIENCE AND STUDY GAMES ABOUT IGNEOUS

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FREE SCIENCE AND STUDY GAMES ABOUT IGNEOUS

ROCKS EXAM QUESTIONS

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -18 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation

Question 1: Phenocryst

Answer:

A large or conspicuous crystal in a porphyritic rock, distinct from the groundmass.

Question 2: Extrusive

Answer:

Relating to or denoting rock that has been extruded at the earth's surface as lava or other volcanic deposits.

Question 3: Glassy Texture

Answer:

The texture of certain igneous rocks, such as obsidian, that contain no crystals.

Question 4: Volatiles

Answer:

Found in varying amounts in nearly all wall rocks and magmas figure prominently in the magmatic differentiation process of assimiliation.

Question 5: Bowen's Reaction Series

Answer:

The work of the petrologist, Norman L. Bowen who was able to explain why certain types of minerals tend to be found together while others are almost never associated with one another.

Question 6: Felsic

Answer:

A term used to describe an igneous rock that has a large percentage of light-colored minerals such as quartz, feldspar, and muscovite.

Question 7: Pyroclastic Texture

Answer:

Texture resulting from the consolidation of individual rock fragments that are

Question 8: Andesite

Answer:

A fine-grained, extrusive igneous rock composed mainly of plagioclase with other minerals such as hornblende, pyroxene and biotite.

Question 9: Intrusive

Answer:

Of, relating to, or formed by intrusion.

Question 10: Magma

Answer:

Hot fluid or semifluid material below or within the earth's crust from which lava and other igneous rock is formed by cooling.

Question 11: Aphantic Texture

Answer:

A texture of igneous rocks in which the crystals are too small for individual minerals to be distinguished with the unaided eye.

Question 12: Basalt

Answer:

A dark-colored fine-grained extrusive igneous rock composed mainly of plagioclase feldspar and pyroxene.

Question 13: Pegmatitic Texture

Answer:

This texture is found in intrusive rocks. The extra large size does not mean that they cooled extra slowly.Instead, the large crystals of a pegmatite formed in a magma that was extra rich in dissolved water.

Question 14: Phaneritic Texture

Answer:

The crystals are roughly equal in size and large enough so that individual minerals can be identified with the unaided eye.

Question 15: Intermediate

Answer:

An igneous rock that has an intermediate silica content. Examples are syenite and diorite. Also see entries for acidic, basic and ultrabasic rocks

Question 16: Mafic

Answer:

Relating to, denoting, or containing a group of dark-colored, mainly ferromagnesian minerals such as pyroxene and olivine.

Question 17: Granite

Answer:

A coarse-grained, intrusive igneous rock composed primarily of light colored minerals such as quartz, orthoclase, sodium plagioclase and muscovite mica.

Question 18: Ultramafic

Answer:

Relating to or denoting igneous rocks composed chiefly of mafic minerals.