Glossary

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  • delta

    A deposit of sand and other sediment, usually triangular in shape. Deltas form at the mouths of rivers where the water flows into the sea.

  • deposition

    The laying down of sediment such as sand, soil, clay, or gravel by wind or water. It may later be compacted into hard rock and buried by other sediment.

  • Devonian Period

    The interval of geologic time between 419 million and 359 million years ago.

  • dissolution

    See solution.