Rocks Quiz Review
1. What are the three main types of sedimentary rocks?
a. Clastic, organic, chemical
2. How are clastic rocks formed?
a. Lithofication
3. What is the primary feature of sedimentary rocks?
a. fossils
4. Define porphyroblasts.
a. Large crystals of new metamorphic rocks.
5. Define hydrothermal metamorphism.
a. Occurs when very hot water reacts with rock.
6. Define metamorphic rock.
a. Rock whose texture, mineralogy, or chemical composition has been altered without
melting.
7. Define sedimentary rock.
a. Rocks that are formed from the cementation of sediments.
8. Define igneous rock.
a. Rock that is formed from the crystallization of magma.
9. Define magma.
a. Slushy mix of molten rock, glass, and mineral crystals
10. Describe Bowen’s Reaction series.
a. Illustrates the relationship between cooling magma and mineral formation. There are
two branches:
i. Right branch represents feldspar minerals, which undergo a continuous change
of composition.
ii. Left branch represents iron and magnesium rich minerals that change
discontinuously.
11. Define ore.
a. A mineral containing a useful substance that can be mined for profit.
12. What affects the melting temperature of magma?
a. Silica content
13. What affects the formation of magma?
a. Temperature, pressure, and mineral composition
14. Describe weathering.
a. Chemical or mechanical process that breaks down and changes rocks on or near Earth’s
surface and whose rate is influenced by factors such as precipitation and temperature.
15. Define kimberlites.
a. Rare, ultramafic rock that can contain diamonds and other minerals formed only under
very high pressures.
16. Differentiate between physical and chemical weathering.
a. Chemical – when the minerals in a rock are dissolved or otherwise chemically changed.
b. Physical – minerals remain chemically unchanged.
17. Define graded bedding.
a. Depositional feature of sedimentary rock in which particles are progressively heavier
and coarser toward the bottom layers of bedding.
18. Define porosity.
a. Percentage of open spaces between grains in a rock; is highest in well-sorted sediments.
19. Explain the rock cycle.
a. Set of processes whereby rocks continuously change into other types of rocks.
20. Is it possible for a rock to change from sedimentary to sedimentary (or igneous to igneous or
metamorphic to metamorphic) without changing to a different type in between? How?
a. Yes. While the rock cycle is a continuous process, it is not a set process. For example, a
sedimentary rock may be weathered into sediments, which combine with other
sediments to become a different sedimentary rock.
21. Study your vocabulary!
22. Study the rock cycle page!