(LAC-58) Geologic map of the Copernicus quadrangle of the moon
Dates
Publication Date
1967-01-01
Time Period
1963-01-01
Citation
H. H. Schmitt, 19670101, (LAC-58) Geologic map of the Copernicus quadrangle of the moon: , https://doi.org/10.5066/P9WBF3VK.
Summary
The surface of the Moon is heterogeneous both on a regional and a fine scale. The geologic mapping of this surface is similar in principle to the geologic mapping of the Earth's surface and depends on the discrimination of similarities and differences between materials and features at different points on the surface. Differences from area to area in characteristic topographic forms and in such physical properties as albedo indicate that the areas are underlain by materials of different nature and have formed under different processes. The units shown on the map are analogous to stratigraphic units adopted for mapping terrestrial geology in that they are bodies of rock with a limited range of properties and age and are of relatively [...]
Summary
The surface of the Moon is heterogeneous both on a regional and a fine scale. The geologic mapping of this surface is similar in principle to the geologic mapping of the Earth's surface and depends on the discrimination of similarities and differences between materials and features at different points on the surface. Differences from area to area in characteristic topographic forms and in such physical properties as albedo indicate that the areas are underlain by materials of different nature and have formed under different processes. The units shown on the map are analogous to stratigraphic units adopted for mapping terrestrial geology in that they are bodies of rock with a limited range of properties and age and are of relatively simple geometric form. It is inferred that the material of the individual rock units mapped has formed under a limited set of conditions. The relative ages of some of the map units can be determined where they overlap. For example, the rays around Copernicus overlap the craters Eratosthenes and Reinhold and the rim materials of Copernicus, Eratosthenes, and Reinehold overlap the smooth materials of the maria. The relative age of each unit determines its position in the stratigraphic column that has been worked out for the region around Mare Imbrium and that is based on events that affected much of the surface of the Moon (Shoemaker and Hackman, 1962). The major divisions of the stratigraphic column are called systems; each system corresponds to a period of time whose salient events in the area around Mare Imbrium are listed in the table below, the most recent at the top. PERIOD EVENTS: Copernican Formation of ray craters; Eratosthenian Formation of large craters whose rays are no longer visible Imbrian Deposition of the extensive mare material of the Procellarum Group; Crater formation; Events related to the formation of Imbrium basinpre-Imbrian time Crater formation; formation of other mare basins(not yet formally divided)The symbol for each map unit consists of two parts: an abbreviation of its age assignment (capital) and an abbreviation of its name (lower case). The units are arranged in chronologic order in the explanation; the distinguishing characteristics of each are followed by and interpretation of its origin or composition. The values or normal albedo were derived from microdensitometer measurements of full Moon photographs calibrated with photoelectrically derived albedos of selected points (unpublished data by Pohn and Wildey, U.S. Geological Survey).
Digitized 1:1,00,000-scale geologic map of the LAC-58 Copernicus quadrangle of the moon. Originally mapped on Lunar Base Chart USAF-ACIC imagery. The scanned map sheet was imported into ArcMap and georeferenced to the more current 2013 global WAC mosaic basemap. Contacts and geologic units were digitized and attributed based on type and unit name.
