| A | B |
|---|
| abrasion | physical weathering of rocks as they rub together |
| absolute age | real age in years |
| air mass | large body of air with similar pressure, moisture, wind and temperature |
| air pressure | weight of air pushing down |
| angle of insolation | angle at which Sun's rays strike Earth |
| arid | very dry |
| asteroids | rocks that orbit the Sun |
| banding | layers in metamorphic rocks |
| barometer | instrument that measures air pressure |
| capillarity | the ability of water to rise in small openings |
| carbon-14 | radioactive, used to date fossils |
| cementation | minerals "glue" particles together to make sedimentary rocks |
