Data

The Phoenicis Lacus quadrangle (named Lake of the Phoenix by Schiaparelli, 1877) includes some of the largest geologic features recognized on the terrestrial planets. Arsia and Pavonis Montes, (South Spot and Middle Spot of Marine 9) rise 18 and 17 km, respectively, above the surrounding plateau to an elevation large volcanoes Ascraeus and Olympus Montes, located outside the quadrangle to the nor

The Noachis quadrangle is in the ancient cratered highlands of Mars. Craters dominate the surface of the planet in this area; most are of impact origin, some are of volcanic origin, and some are of undetermined origin. Impact craters in the Noachis quadrangle are classified into four groups based on their morphologic characteristics, each group representing a relative age range. Where applicable,

The Syrtis Major quadrangle is located in the equatorial belt of Mars across the boundary between the cratered plateau region to the south and west and the northern lowland plains. The cratered plateau is part of the northern extension of cratered highlands, which generally stand at altitudes greater than 4 km. The southeastern part of the quadrangle is dominated by eastward-sloping plains on th

The Amazonis quadrangle lies within the northern sparsely cratered hemisphere of Mars (Carr and others, 1973). The dominant structural and physiographic features of the quadrangle are low featureless plains (Amazonis Planitia) in the center third of the quadrangle, the western flanks of the large volcanic construct, Olympus Mons, and its associated aureole deposits (Lycus Sulci), which lies on the

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

Two principal physiographic province of Mars are represented in the Aeolis quadrangle: (1) Elysium Planitia in the north is part of a broad planet-encircling belt of relatively young lowland plains, and (2) cratered highlands in the south consist of rough primitive terrain that extends to polar deposits around the southern ice cap (Condit and Soderblom, 1978; Scott and Carr, 1978). These two terr

The Memnonia quadrangle lies astride the boundary between heavily cratered and sparsely cratered hemispheres of Mars (Carr and others, 1973). Densely cratered terrain occurs in the southwestern part of the quadrangle. Strips of plains material bound the cratered terrain in both the northern and eastern parts of the quadrangle. There is approximately 3 km of relief across the quadrangle, with th

Relative ages of structures and geologic units have been determined from intersection and apparent overlap relations and from morphologic freshness reflecting degree of preservation. The fivefold crater-age sequence is based on the classification of Shoemaker and Hackman (1962), and corresponds broadly to a modified classification of Pohn and Offield (1970) and Offield (1971). Rock units in the qu

The geology of the Argyre quadrangle of Mars is dominated by the conspicuous Argyre basin, defined by a rim of rugged mountain blocks that surrounds a nearly circular expanse of plains 800 km across. Of the large (greater than 500 km in diameter) basins identified on Mars, Argyre is the best preserved and probably the youngest. Basins appear to be traps for eolian debris and evidently are source a

The Sinus Sabaeus quadrangle lies in the southern equatorial region of Mars. It is bounded on the north by the equator, on the west by the central meridian, on the south by lat 30 degrees S., and on the east by long 315 degrees W. Three classical regions that have low albedos occur within the quadrangle (Lowell Observatory, 1971): (1) half of Sinus Meridiani occupies part of the northwest corner o

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 physical properties such as topography, visible under low-illumination and albedo, the reflectivity under full-Moon illumination. Such units are considered analogous to the rock-stratigraphic formations of terrestrial geology. By application of t

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 phy