Geologic map of the west side of the Moon

IMAP 1034
By: , and 



The west limb region of the Moon consists of highly cratered terra rising 5 km or more above the mare of Oceanus Procellarum and most of the lunar near side. Crustal material in this area of large basins and craters has been redistributed repeatedly by giant impacts. The early historical record of these events is apparently preserved in a complex of interlayered breccias, which may be partly exposed in the walls of the larger craters. Orientale, the last multiringed basin, was formed early in lunar history during the wanning stages of high impact flux by a large body probably impacting the surface obliquely from the northeast. Ejecta from this impact was widely scattered by over the Moon and appears to form some of the plains materials. Although the major landforms of the Oriental basin were developed instantaneously in geologic terms, isostatic adjustments were more protracted; the accompanying structural dislocations including concentric and radial faults in the floor material may have continued up to the time of mare basalt flooding after basin formation. Subsequent impacts have produced craters generally less than 60 km diameter. 

Publication type Report
Publication Subtype USGS Numbered Series
Title Geologic map of the west side of the Moon
Series title IMAP
Series number 1034
Subseries NONE
DOI 10.3133/i1034
Year Published 1977
Language English
Publisher U.S. Geological Survey
Description 1 map
Other Geospatial Moon
Scale 500000
Google Analytic Metrics Metrics page
Additional publication details