Heavy Minerals can tell may stories(RM-02)
Unlike the natural separation of different weights of sediments by running water, light minerals in the laboratory are floated away by specially formulated liquids. The heavy minerals are then mounted on glass slides for microscopic study. There are many varieties of heavy minerals, and each grain tells a story. An angular grain of hornblende may indicate geologically recent glacial transport from granite outcrops in Canada. The relation of epidote grains to garnet grains may also help tell where the ice came from.
Rounded mineral grains may have a long and complex history. A well-rounded frosted grain may have had several cycles of erosion, transportation, and deposition by streams, waves, wind, or glaciers.
Our Hoosier State Beneath Us: Rocks and Minerals