Medical Definition of amnesia. 1: loss of memory sometimes including the memory of personal identity due to brain injury, shock, fatigue, repression, or illness or sometimes induced by anesthesia a period of amnesia after the wreck.
Shale is a fine-grained sedimentary rock that forms from the compaction of silt and clay-size mineral particles that we commonly call mud. This composition places shale in a category of sedimentary rocks known as mudstones.
When igneous rocks are exposed to weathering, many of their common minerals completely dissolve or partially dissolve and convert into clay minerals. As a result, olivine, pyroxene, plagioclase, amphibole, and biotite are uncommon in sedimentary rocks.hen igneous rocks are exposed to weathering, many of their common minerals completely dissolve or partially dissolve and convert into clay minerals. As a result, olivine, pyroxene, plagioclase, amphibole, and biotite are uncommon in sedimentary rocks.