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A weathered layer of bedrock. pegmatite Exceptionally coarse-grained igneous rock. pelite A descriptive name for a clastic rock with a grain size of less than 1/16 mm (originally sand or silt). peridotite An olive green when fresh, medium brown when weathered, saccharoidal intrusive igneous rock composed mainly of olivine, sometimes with pyroxene.
Etchplain – Plain where the bedrock has been subject to considerable subsurface weathering; Exhumed river channel – Ridge of sandstone that remains when the softer flood plain mudstone is eroded away; Fjord – Long, narrow inlet with steep sides or cliffs, created by glacial activity
This glossary of geography terms is a list of definitions of terms and concepts used in geography and related fields, including Earth science, oceanography, cartography, and human geography, as well as those describing spatial dimension, topographical features, natural resources, and the collection, analysis, and visualization of geographic ...
The geology of North America is a subject of regional geology and covers the North American continent, the third-largest in the world. Geologic units and processes are investigated on a large scale to reach a synthesized picture of the geological development of the continent.
There are two main types of channels, bedrock and alluvial, which are present no matter the sub-classification. Bedrock channels are composed entirely of compacted rock, with only patches of alluvium scattered throughout. Because the bedrock is constantly exposed it takes much less stream power to carve the channel.
Parent material is the underlying geological material (generally bedrock or a superficial or drift deposit) in which soil horizons form. Soils typically inherit a great deal of structure and minerals from their parent material, and, as such, are often classified based upon their contents of consolidated or unconsolidated mineral material that has undergone some degree of physical or chemical ...
The following is a list of rock types recognized by geologists. There is no agreed number of specific types of rock. Any unique combination of chemical composition, mineralogy, grain size, texture, or other distinguishing characteristics can describe a rock type. Additionally, different classification systems exist for each major type of rock. [1]
Some of the types of information that cannot be obtained except from bedrock outcrops or by precise drilling and coring operations, are structural geology features orientations (e.g. bedding planes, fold axes, foliation), depositional features orientations (e.g. paleo-current directions, grading, facies changes), paleomagnetic orientations