Rocks

4. hot fluid or semifluid material below or within the earth's crust from which lava and other igneous rock is formed on cooling.
5. The quality of being hot; high temperature
9. Formed from cooled and solidified magma, or molten rock
11. The remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock.
12. The theory that changes in the earth's crust during geological history have resulted from the action of continuous and uniform processes.
13. The process by which rocks, minerals, and other materials break down or change in composition, color, texture, or form at or near the Earth's surface
14. A long-lived naturally occurring radioactive carbon isotope of mass 14, used in carbon dating and as a tracer in biochemistry.
15. A solid collection of minerals.

1. The time taken for the radioactivity of a specified isotope to fall to half its original value.
2. A person who studies or is an expert in the branch of science concerned with fossil animals and plants.
3. A method used to determine the age of an object or event in relation to other objects or events, without assigning a specific numerical age.
6. A fossil that is useful for dating and correlating the strata in which it is found.
7. Matter that settles to the bottom of a liquid; dregs
8. Formed when existing rocks are transformed into new types of rock through a process called metamorphism
10. A method for determining the age of an object or event in years