An overview of geological results from Mariner 9
Abstract
Mariner 9 acquired pictures of all of Mars. From these data, preliminary scale photomosaics have been made of the entire planet, and a 1:25,000,000 scale shaded relief map published. The more than 7300 pictures acquired indicate that Mars is more varied and dynamic than previously inferred. About one half of the surface consists of ancient cratered terrain. The remainder of the surface is covered either by younger volcanic rocks and constructs that stand as much as 17 km above the mean level or by extensive tracts of plains deposits, some of which are sedimentary in origin. The volcanic piles with summit calderas have fresh flank flows and appear to be geologically young. The great equatorial chasm or canyon system terminates in a complexly faulted plateau to the west and in large patches of chaotic terrain on the east. Large fluvial channels originate in this chaotic terrain possibly by melting of permafrost and appear to flow northward into the Chryse region. Many small dendritic channel networks abound in the equatorial regions and imply possible collection of rainfall. In addition, many small lava channels with distinctive characteristics are present. Many of the basin floors are underlain by lava flows inferred to be basaltic from the form of the flows, ridges, and domes that characterize their surface. The polar regions are covered by glacio-eolian layered sediments that appear to be still forming.
- Publication:
-
A Primer in Lunar Geology
- Pub Date:
- July 1974
- Bibcode:
- 1974plug.nasa..467M
- Keywords:
-
- Astronomical Photography;
- Geology;
- Mars Surface;
- Photomapping;
- Canals;
- Mariner 9 Space Probe;
- Meteorite Craters;
- Polar Caps;
- Topography;
- Volcanology