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.
The continental crust is made up of sedimentary, igneous and metamorphic rock. Sedimentary rocks are rocks that have been formed by atmospheric pressure, living organisms and gravity. They are created when sediments consolidate over eons. Igneous rocks are formed by the cooling of magma, found deep in the Earth, or lava flows.