Data

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...

The Magellan spacecraft orbited Venus from August 10, 1990, until it plunged into the venusian atmosphere on October 12, 1994. Magellan had the objectives of (1) improving knowledge of the geologic processes, surface properties, and geologic history of Venus by analysis of surface radar characteristics, topography, and morphology and (2) improving knowledge of the geophysics of Venus by...

The Sappho Patera quadrangle (V-20) of Venus is bounded by 0 degrees and 30 degrees East longitude, 0 degrees and 25 degrees North latitude. It is one of 62 quadrangles covering the entire planet at a scale of 1:5,000,000. The quadrangle derives its name from Sappho Patera, a large rimmed depression (diameter about 225 km) lying on top of a shield-shaped mountain named Irnini Mons...

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 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...

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...

The Oxia Palus quadrangle contains three distinct geologic provinces: (1) an elevated cratered plateau that occupies three-fourths of the quadrangle and is similar to much of the southern hemisphere of Mars; (2) the low, relatively featureless Chryse Planitia in the northwest corner; and (3) a complex province of chaotic terrain and immense channels or valleys that divides the plateau an

The Coprates quadrangle lies to the east of the Tharsis volcanic complex and the Noctis Labyrinthus tectonic complex. To the north are the plains of Lunae Planum, to the east the vast patches of chaotic terrain and the large sinuous channels that trend northward into Chryse Planitia. On the southwest is the Thaumasia Fossae region of tectonically deformed cratered terrain, to the...

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 Casius quadrangle (30 degrees N to 65 degrees N lat; 240 degrees W to 300 degrees W long) is one of the northern tier of Lambert conformal sheets of the Mars Atlas. It consists of four distinctive physiographic regions: 1) part of the northern cratered plain which forms an incomplete annulus around the north polar region, 2) smooth lowland plains of Utopia Planitia across the central...

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

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...