USGS Science⌕ Search

SEARCH · USGS Science

Results for “Geologic Quadrangle Map”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 955 records · Page 53Linked to original sources
USGS1979

Geologic map of the Memnonia Quadrangle of Mars

The Memnonia quadrangle lies astride the boundary between heavily cratered and sparsely crater ed 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 the highest elevations in the eastern part. Plains materials of this region are situated along the lower slopes of the Tharsis Montes, which con tinue to rise in elevation eastward in t o the adjacent Pheo nicis Lacus and Tharsis quadrangle. There is little correlation between terrain types and elevation within the Mamnonia quadrangle. In particular , the boundary between cratered terrain and plains for the most part is not marked by any prominent change in elevation .

IMAP↗
USGS1979

Geologic map of the Cebrenia quadrangle of Mars

Most of the Cebrenia quadrangle (lat 30˚ to 65˚ N., long 180˚ to 240˚ W.) is in the circumpolar plains of Mars. Craters from an early episode of intense bombardment have been largely obliterated by later volcanism, tectonism, erosion, and sedimentation by wind and water, and by circumpolar glacial and periglacial processes. South of 47˚ N. the plains are dissected by numerous channels, most of which drained off a broad volcanic upland near the southern border of the quadrangle. The impressive Elysium volcanoes cap the crest of this upland; their northernmost member, Hecates Tholus, lies within the Cebrenia quadrangle. The southeastern part of the Cebrenia quadrangle is dominated by the Phlegra Montes, which may be the only purely tectonic mountain range on Mars. It seems to have been formed by block faulting; there is no evidence that impact of volcanic processes played a role. An ancient pediment appears to have been uplifted by normal faults to form a north- to north-northeast-trending mountain range 1,400 km long, as much as 250 km wide, and more than 1 km high. Its foothills are partly covered by later volcanic and eolian deposits.

IMAP↗
USGS1979

Geologic map of the Phaethontis Quadrangle of Mars

The Phaethontis quadrangle of Mars is dominated by densely cratered uplands and plateaus which form some of the oldest surfaces on the planet. Extensive low-lying areas within the cratered terrains, including the floors of the large craters , are covered to different degrees by plains-forming material. The youngest plains unit surround Tharsis Montes to the north. Various erosional processes, including eolian scour and possibly scarp retreat through volatile-release sapping and mass wasting, producing several distinctive physiographic features: knob and mesa terrains, plains and small knobs, and plateaus dissected by furrows, steep walled gorges, and pits.

IMAP↗