Sedimentary rocks are a result of the erosion, transportation, deposition, and compaction (lithification) of rock fragments and minerals derived from other rocks. These grains are weathered and broken away from existing rocks by the action of water, wind and ice. The deposited rock fragments and grains are squeezed tightly together and compacted, finally these fragments are cemented together by thin layers of mineral matter such as silica and calcite. Sandstone, an example of a sedimentary rock, is formed of sand-sized grains that are often quartz grains. Some sandstone is very hard and resistant to erosion, other sandstone is very brittle and can come apart in your hand. This video illustrates very brittle sandstone found in the badlands of Drumheller. This sandstone is so soft that it literally comes apart when rubbed with ones foot. It is clear by the shape of the sandstone that it is not very resistant to erosion, obvious from the wavy like shape it exhibits.
No comments:
Post a Comment