Data

Volcanoes are among the most imposing and geologically interesting features on Mars. Nearly 60 percent of the planets surface is covered by volcanic rocks dating from the Early Noachian to Late Amazonian Epochs (Tanaka and others, 1988). This map of the volcano Apollinaris Patera and surrounding area is one of a series of large-scale (1:500,000) geologic maps initiated by the National Aeronautics

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

This map is one in a series of 1:500,000-scale geologic maps initiated by the National Aeronautics and Space Administration to investigate areas of particular scientific interest on Mars. The north Kasei Valles area (fig. 1) merits detailed geologic study because it contains part of a large channel system whose age can be determined relative to geologic units that range in age from early intermedi

The Beethoven quadrangle is located in the equatorial region of Mercury, in the center of the imaged area. Most pictures of the quadrangle were obtained at high sun angles as the Mariner 10 spacecraft receded from the planet. Images in the northeastern part of the quadrangle are very poor to unusable. Another difficulty in mapping is the poor match in topographic bases between Beethoven and adjace

Material exposed on the surface of the Moon is heterogeneous. The albedo and other physical characteristics that have been determined with the use of optical and radio telescopes vary from one part of the Moon to another, and the variations are partially correlated with differences in topography. Discontinuities in the areal variation permit the surface material to be divided into map units, each

The Wilhelm quadrangle lies along a mare highlands boundary west of the crater Tycho, southeast of Mare Humorum, and southwest of Mare Numbium. The outer scarp of the Orientale basin is 1200 km to the West-Northwest. The quadrangle is characterized by pitted and mantled appearing terra, which in the north is interrupted by patches of mare and in the south by several large pre-Imbrian craters. Most

The Diacria quadrangle lies within the north circumpolar lowlands of Mars (Carr and others, 1973; Scott and Carr, 1978). The dominant structural and physiographic features are low, relatively smooth plains (Arcadia Planitia, Vastitas Borealis) that form the northern two-thirds of the quadrangle. The plains rise to the south to form the north edge of the Amazonis Planitia and to the southeast tow

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,

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 Systematic mapping of lava flow units in the Tharsis region has been compiled into a series of 16 maps at 1:2,000,000 scale. This work provides information on the sources and areal extent of the lava flows, on their eruptive sequences and relative ages, and on relations between the flows and geologic structure in the largest, most active tectonic and volcanic province on Mars. Some of the maps

The area shown on this map includes layered polar deposits and residual polar ice, as well as some exposures of older terrain. Howard and others (1982) noted that an area (at lat 84.8 S., long 356 W.) near a 23-km diameter impact crater (Plaut and others, 1988) appears to have undergone recent deposition, as evidenced by the partial burial of secondary craters. Herkenhoff and Murray (1990a) mapped

The geology for this map was compiled using Viking Orbiter images on 1:500,000- scale photomosaics of the Mars Transverse Mercator quadrangles -40262, -40267, and -40272. This map represents a detailed extension of regional geologic mapping of the east Hellas rim (Crown and others 1990, 1992) and is published at 1:1,000,000 scale. The map area is on the east rim of one of the largest impact struct