i. built from ejected gas-rich lava fragments. Steep slope of loose cinders. They have small size and short eruption periods.
Minerals with same composition but different crystalline structures. E.g. graphite & diamond both composed of carbon.
reaction of mineral with water. Hydrogen ion attacks and replaces other ions. E.x hydrolysis of Feldspar to clay minerals.
exposure to atmospheric oxygen.
Factors controlling soil formation:
1. Climate: Most influential control. Key factors are temperature and precipitation.
2. Time: Amount of time soil formation caries for different soils depending on geologic and climate conditions.
3. Plants & Animals: influence soil physical & chemical properties. Microorganisms, worms.
4. Topography: steep vs. gentle slopes.