These are richer in acidic cations. Weather to less fertile soil. Location of rock formation with respect to earth's surface. Slow cooling means large crystals grow. E.g. granite has conspicuous crystals of quartz, feldspar.
Basalts are volcanic, micro-crystalline rock.
2. occurs as lava, which flows over surface and cools. 3. occurs as tephra, which solidifies in air and falls to earth as volcanic ash deposits. B. Sedimentary rocks are made of weathered and eroded rock particles. Sediments are materials that are eroded from uplands and carried to lower elevations and deposited by running water, wind, ice. Sediments may be deposited in lakes, streams, depressions, oceans basins.