Data Releases

The multi-ringed Nectaris basin (Hartmann and Kuiper, 1962) dominates the Fracastorius quadrangle. The basin is 840 km across as measured from the outermost ring and lies athwart four quadrangles. Fracastorius, the southeastern quadrangle, straddles the three rings of the basin (fig. 1). In this quadrangle most pre-Imbrian structures and many depositions were formed by the Nectaris impact. Further

The Geminus quadrangle, centrally located in the northeast quadrant of the lunar near side, is dominated geologically by several multiringed circular basins outside the quadrangle and five relatively young, large craters mapped here. The terra and the older craters apparently are mantled by a nearly continuous blanket of ejecta from the Serenitatis, Crisium, Humboldtianum, and Imbrium basins, whic

The Grimaldi quadrangle lies at the southwest margin of Oceanus Procellarum about 1,000 km east of Orientale, the youngest of the lunar multi-ringed basins. The distal ends of the ejecta blanket surrounding the Orientale basin partly covers the western third of the quadrangle. The relatively small, two-ring Grimaldi basin is in the northwest corner of the quadrangle, and the Humorum basin lies abo

The area of MC-28 is centered at the east edge of the Hellas Planitia (Hellas basin and surrounding plains) within densely cratered terrain that covers more than half the surface of Mars (Carr, 1973). The deepest part of the basin lies 4-5 km below the surface of the cratered terrain (Hanel and others, 1972). An irregular band of mountain and knobby material about the eastern margin of the basin

The surface of the Moon is heterogeneous. Surface materials are classed on the basis of telescopic observations into units, each having a limited range of topographic and other physical such as albedo, the reflectivity under full-Moon illumination. Such units are considered analogous to the rock-stratigraphic formations of terrestrial geology. By application of the principals of superposition and

The Hommel quadrangle is in the southeast highlands of the earthside hemisphere of the Moon. The major geologic units are smooth and ridged terra materials, plains-forming materials and crater materials Mare material is absent. In the absence of extensive stratigraphic datum horizons, the geologic units were tentatively correlated with the type areas of the lunar geologic systems (Shoemaker and Ha

The Iapygia quadrangle, in the equatorial region of Mars just north of the Hellas basin, is mainly ancient, hilly, and cratered upland terrain. The southern one-third of the quadrangle is dominated by mountain and knobby materials representing mountains of pre-Hellas material and material related to the Hellas basin and mappable in a 500-km-wide zone circumjacent to it. The northeast quadrant of t

The Ismenius Lacus quadrangle includes the northernmost extension of the crated highlands that occupy a major part of the southern martian hemisphere. It includes three prominent physiographic provinces: cratered highlands in the south, relatively featureless plains in the middle, and mottled plains in the north. The highlands are separated from the plains by a belt of dissected terrain, containin

Basic information about the planetary surface of the Kuiper quadrangle is provided by three sequences of high-quality photographs designated Mercury I, II, and II, obtained during the incoming phases of three encounters of the Mariner 10 spacecraft with Mercury. Mercury I includes 75 whole-frame photographs of the Kuiper quadrangle; Mercury II, 13 whole-frame photographs; and Mercury III, 70 quart

The Langrenus quadrangle is on the east limb of the lunar nearside, at the southeast margin of Mare Fecunditatis. The crater Langrenus, about 140 km in diameter, is the most prominent feature. Rugged terra materials, scattered by craters of various sizes and ages, occupy much of the east half of the map area, and smooth mare materials in the Fecunditatis basin dominate the west. Mare Spumans and o

The Lavinia Planitia quadrangle (V-55) is in the southern hemisphere of Venus and extends from 25 degrees to 50 degrees south latitude and from 330 degrees to 360 degrees longitude. It covers the central and northern part of Lavinia Planitia and parts of its margins. Lavinia Planitia consists of a centralized, deformed lowland flooded by volcanic deposits and surrounded by Dione Regio to the west

Mars presents two different terrains, a highly cratered surface that lies mostly in the southern hemisphere and sparsely cratered plains that lie mostly in the northern hemisphere. The cause of the dichotomy is a still unsolved fundamental problem of Martian geology, analogous to the problem of continents and ocean basins in terrestrial geology. The present features of the plains in particular r