Data Releases

The Macrobius quadrangle is in the northeast quadrant of the Moon's near side. Although predominantly a highland area centered around the Taurus Mountains (Montes Taurus), it is bounded by three major mare-filled basins: Tranquillitatis, the oldest, to the south; Serenitatis to the west; and Crisium on the east. Most of the geologic units within the quadrangle have been profoundly affected by the

The Mare Boreum geologic map portrays the north polar are of Mars above lat 65 degrees N. The area contains five physiographic provinces: (1) a residual ice cap characterized by troughs with a counterclockwise outward spiral pattern (Mariner 9 frames DAS 13317550 and DAS 13353320); (2) layered terrain adjacent to the ice cap, exposed within the spiral troughs; (3) a circumpolar band of low-albedo

The Mare Tyrrhenum quadrangle is bounded by lat 0 degrees and 30 degrees S. and long 225 degrees W. and 270 degrees W. The central part of the quadrangle is dominated by Tyrrhena Patera, a large shield volcano, and associated low-albedo ridged plains that probably are basaltic lava flows similar to the lunar maria. The western, northern, and eastern margins of the quadrangle are located in crater

The map area contains two mare provinces, one terra province, and one province of mixed mare and terra. The maria are the semicircular southern half of Mare Crisium and the northeast sector of Mare Fecunditatis. The massive belt of terra that arcs across the quadrangle between these maria is the south rim of the Crisium multiringed basin; its southwest part is probably superposed on an older, orig

The Margaritifer Sinus quadrangle lies within a broad north-sloping trough, the Chryse lowland, between the elevated Tharsis plateau to the west and the cratered upland to the east. The rugged, uniquely martian chaotic terrain is best developed in this quadrangle. Sinuous furrows a few kilometers wide and as much as several hundred kilometers long cover most of the quadrangle; in several places ar

Although geologic mapping fo the Moon has its own techniques and problems, systematic observation and the application of established geological principles have allowed the materials and structures of its surface to be delineated and classified into units (Shoemaker and Hackman 1962; McCauley 1967; Wilhelms, 1970). Most of these units are material entities similar to terrestrial rock-stratigraphic

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

Mariner 10 data include complete photographic coverage of the quadrangle at a resolution of about 2 km. In addition, twelve stereopairs cover scattered areas in the quadrangle (Davies and others, 1978, p. 114-115); these photographs were used to supplement the geologic interpretation. About 10 degrees of longitude of the H-13 quadrangle (Solitudo Persephones Province) adjacent to the west is inclu

Mangala Valles are a system of outflow channels cut into Terra Sirenum that appear to originate from a fracture of Memnonia Fossae radial to the Tharsis volcanic center (about 1,800 km to the east).

This map is one in a series of 1:500,000-scale geologic maps prepared to investigate areas on Mars of high scientific interest. The quadrangle contains the source area for Mangala Valles, one of the largest outflow channel complexes on Mars (Sharp and Mali, 1975). Preliminary mapping by Masurksy and others (1986), Simbelman (1988), and Champlan and others (1989, 1991) showed that several episodes

Published geologic maps of south polar region of Mars have been based on either Mariner 9 (Condit Soderblom, 1978; Scott and Carr, 1978) or Viking Orbiter (Tanaka and Scott, 1987) images. The mapped extent of the southern layered deposits differs in many places on these maps and on our maps. These differences reflect the difficulty in accurately determining the location of the contact between the

The polar deposits on Mars are of great interest because they probably record martian climate variations (Thomas and others, 1992). The area shown on this map includes polar layered deposits with distinct low-albedo features and a sharp boundary between the layered deposits and the moderately cratered unit that forms the floor of Chasma Australe. Detailed mapping of this quadrangle was undertaken