by Libby Schaaf

- a mountain made up by rock layers squeezing together

-a mountain made by huge tilted blocks of rocks

-the natural process of breaking down of rocks

-the picking up and removal of rock particles

-a mixture of weathered rock, humus, living things, water, and decayed remains

-material in soil formed by plant and animal material

-any layer of soil from the surface to bedrock

-water that soaks into rock and soil through spaces between rock particles

-the downhill movement of Earth material from gravity

-the dropping off of sediment

-a big sheet of ice and snow that moves slowly over land

-a jumble of many kinds of sediment deposited by a glacier

-a deposit of many sizes of sediment in front of along a glacier

- a natural occurring solid in Earth's crust

- a rock that forms when hot, liquid lava cools and hardens

- a rock that forms when other pieces of rock are squeezed into one

-a rock that forms from a different rock that is changed by heat, pressure, ect.

- rocks continually changing in a never-ending process

-the idea that in a series of rock layers, the bottom is oldest and the top is youngest

-the age of a rock as compared with another rock

-a listing of Earth's rock layers from oldest to youngest

- a trace, imprint, or remains of a living thing preserved in Earth's crust

- the remains of a living thing that was widespread but only lived a short period of time

-the time it takes for half the mass of a radioactive element in a rock to break, decay, into other elements

-the absolute age of a rock in yrs., as determined by measuring the decay rate

- one of the four long stretches of time in Earth's history: currenntly the cenozoic era