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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.
Minnesota Geological Survey via Minnesota Geologic Topics; select Bedrock Geology, then select Geologic Map of Minnesota's Bedrock Geology: Author: Mark A. Jirsa, Terrence J. Boerboom, V.W. Chandler, John H. Mossler, Anthony C. Runkel, and Dale R. Setterholm: Permission (Reusing this file)
Etchplain – Plain where the bedrock has been subject to considerable subsurface weathering Flared slope – Rock-wall with a smooth transition into a concavity at the foot zone Flute – in geology, process of differential weathering and erosion that produces a corrugated surface of ridges or flutes Pages displaying wikidata descriptions as a ...
Also called Indianite. A mineral from the lime-rich end of the plagioclase group of minerals. Anorthites are usually silicates of calcium and aluminium occurring in some basic igneous rocks, typically those produced by the contact metamorphism of impure calcareous sediments. anticline An arched fold in which the layers usually dip away from the fold axis. Contrast syncline. aphanic Having the ...
Superficial deposits (or surficial deposits [1]) refer to geological deposits typically of Quaternary age (less than 2.6 million years old) for the Earth. These geologically recent unconsolidated sediments may include stream channel and floodplain deposits, beach sands, talus gravels and glacial drift and moraine.
In geology, a bed is a layer of sediment, sedimentary rock, or volcanic rock "bounded above and below by more or less well-defined bedding surfaces". [1] A bedding surface or bedding plane is respectively a curved surface or plane that visibly separates each successive bed (of the same or different lithology) from the preceding or following bed.
Lake Superior is an example of this northeast–southwest structural trend. Ridges of erosion-resistant rock rise above valleys and carved into weaker rock units. [15] The effects of repeated glaciation have left their mark on the Superior Upland. The present glacial topography is the product of the most recent glaciation that ended just 10,000 ...
The name consists of the geographic name plus either "Formation" or a descriptive name. Examples include the Morrison Formation, named for the town of Morrison, Colorado, and the Kaibab Limestone, named after the Kaibab Plateau of Arizona. The names must not duplicate previous formation names, so, for example, a newly designated formation could ...