Data Releases

The Tharsis quadrangle lies within the sparsely cratered hemisphere (Carr and others, 1973) of Mars. Its geology is dominated by young volcanic features, including both circular constructs and lava plains; little evidence of primitive densely cratered terrain remains. Included are three of the four largest shield volcanoes in the Tharsis province, Olympus Mons, Ascraeus Mons, and Pavonis Mons, t

The Thaumasia quadrangle lies on the south flank of the Tharsis dome (Hord and others, 1974), a large bulge in the crust of Mars extending more than 5,000 km northward from the center of the quadrangle. This major structure imposes a generally southward slope across the entire quadrangle. Topography along the east-central border of the Thaumasia quadrangle exhibits curved scarps and lowlands con

The geology of the Thaumasia region (fig. 1, sheet 3) includes a wide array of rock materials, depositional and erosional landforms, and tectonic structures. The region is dominated by the Thaumasia plateau, which includes central high lava plains ringed by highly deformed highlands; the plateau may comprise the ancestral center of Tharsis tectonism (Frey, 1979; Plescia and Saunders, 1982). The ex

The Tolstoj quadrangle in the equitorial region of Mercury contains the southern part of Caloris Planitia, which is the largest and best preserved basin seen by Mariner 10. This basin, about 1300 km in diameter, is surrounded by a discontinuous annulus of ejecta deposits of the Caloris Group (units cm, cn, co, cvl, and cvs) that are embayed and covered by broad expanses of smooth plains (unit ps).

The Tycho quadrangle is centrally located in the southern half of the earthside hemisphere of the Moon. The area is characterized by a high density of craters, the largest of which – Stofler – is about 140 km in diameter. The northern and eastern parts if the quadrangle are dominated by plains (pIp, Ip) and hilly terra (IpIt) units of regional extent, and the western part by the crater Tycho and i

The Valles Marineris region lies east of Tharsis Montes (which extend from lat 12 degrees to 16 degrees., long 101 degrees to 125 degrees). Part of the region is in the midst of a vast plateau bounded on the west and east by Claritas and Nectaris Fossae, respectively; the remainder extends farther east into southern Xanthe Terr and western Margaritifer Terra. Channel trends, stereophotogrammetry,

Almost all the pictures acquired by Mariner 10 that were used for mapping were obtained during the first encounter: those covering the southeast half of the quadrangle are incoming close-encounter images, and those covering the north-west corner are outgoing close-encounter images. At the time the pictures were obtained, the terminator was at about long 7 degrees to 8 degrees, within the eastern p

The map area, in the Coprates 1:2,000,000-scale quadrangle MC-18 NW lies in the heart of the Valles Marineris trough system. The western part of Ophir Planum (36,660 km2) occupies 40 percent of the map areas; parts of Candor, Melas, and Coprates Chasmata make up the remainder. The troughs contain distinctive landslide deposits, normal faults, possible young volcanic rocks, and layered materials.

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

Olympus Mons is the largest known volcanic construct in the Solar System; it is more than 600 km across and more than 27 km above datum. The volcano and the great scarp that bounds it have been the subject of much scientific controversy. Although it has been possible to generate an empirical model that closely resembles Olympus Mons, the dynamics of scarp formation are still unproven. The scarp ar

The east Mangala Valles area merits detailed geologic study because it contains several small channels whose ages can be determined relative to geologic units that range in age from early (Noachian) to late (Amazonian) periods of Martian history. Because small channels are of three ages and geomorphic types, their study increases our understanding of the continuity of fluvial processes in the evol

The Galindo quadrangle (V-40; centered at lat 12.5 degrees S., long 255 degrees) was geologically mapped at 1:5,000,000 scale under the Venus Data Analysis and Venus Geologic Mapping Programs as part of a project focused on the study of venusian geologic terrains containing assemblages of coronae, arachnoids, and novae; these are enigmatic circular features perhaps related to hot-spot volcanism. M