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Geology topics

Harold Masursky

Publications and source records attributed to Harold Masursky.

At least 19 recordsLinked to original sources
USGS1991

Geologic maps of science study area 3, Olympus Rupes, Mars

This map is one in a series of 1:500,000 -scale geologic maps initiated by the National Aeronautics and Space Administration to investigate areas of particular scientific interest on Mars. 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 (fig, 1, sheet 1). The volcano and the great scarp that bounds it have been the subject of much scientific controversy. Although i t has been possible to generate an empirical model that closely resembles Olympus Mons (fig. 2, sheet 1), the dynamics of scarp formation are still unproven . The scarp area is thus a logical selection as a scientific study area. It has also been designated as a candidate site for a proposed lander/rover/sample-return mission to Mars (fig. 1, sheet 2) not only because the site may provide information about the origins of the scarp and the evolution of Olympus Mons, but also because the rocks of widely diverse ages may be studied from the samples collected from talus at the base of the scarp.

IMAP↗
USGS1991

Geologic map of science study area 1B, west Mangala Valles region of Mars

This map is one in a series of 1:500,000-scale geologic maps initiated by the National Aeronautic and Space Administration to investigate areas of particular scientific interest on Mars. The west 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 the small channels are of three ages and channels of each age are of a geomorphic type unique to that age, their study increases our understanding of the continuity of fluvial process on the evolutionary history of Mars. For these reasons, part of the area is a proposed-site for a sample-return mission to Mars.

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USGS1991

Geologic map of science study area 2, north Kasei Valles, Mars (MTM 25072 Quadrangle)

This map is one in a series of 1:500,000-scale geologic maps initiated by the National Aeronautics and Space Administration to investigate areas of particular scientific interest on Mars. The north Kasei Valles area (fig. 1) merits detailed geologic study because it c ontains part of a large channel system whose age can be determined relative to geologic units that range in age from early intermediate (Early Hesperian) to the very late (Late Amazonian) periods of Martian history . Also, many geomorphic features in the map area suggest changes in water level and multiple erosional events associated with the Kasei Valles system. Later erosional events are indicative of spring sapping ; small-scale, ground-water runoff; and water-mobilized debris flow. Therefore, this large-scale mapping has increased our understanding of the history of hydrolo gic processes on Mars (Chapman and Scott, 1989). For these reasons, part of the area is a candidate site for a sample-return mission to the planet.

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USGS1978

Geologic map of the Phoenicis Lacus Quadrangle of Mars

The Phoenicis Lacus quadrangle (named Lake of the Pheonix by Schiaparelli, 1 877) includes some of the largest geologic features recognized on the terrestrial planets. Arsia and Pavonis Montes, (“South Spot” and “Middle Spot” of Mariner 9) rise 18 and 17 km, respectively, above the surrounding plateau to an elevation of about 27 km above the 6.1 millibar base level. These mountains and the two large volcanoes Ascraeus and Olympus Montes, located outside the quadrangle to the north, are also about 27 km in height , about three times as high as any volcano on Earth. The summit caldera of Arsia Mons. m ore than 100 km in diameter, is the largest known. Syria and Sinai Plana are part of t he highest plat eau on Mars, the Tharsis plateau; their relative elevation, 10 km , is twice that of the Tibetan Plateau, the highest plateau on Earth . Noctis Labyrinthus , the great system of fault valleys at the we st end of Valles Marineris which is located o u tside the quadrangle to the east, displays a more clearly developed system of faults tha n the largest continental fault system on Earth, the East African rift valleys. The land slopes down to the northwest into Amazonis Planitia (fig. 1); the difference in elevation between the volcanic peaks and Amazonis low plains is greater than the relief form the top of the Andes to the bottom of the Peruvian trench. Th is great slope on Mars is similar to the continental shelf and slope that marks the transition bet ween the continents and ocean basin floors of the Ear th.

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USGS1974

North polar region of Mars: Imaging results from Viking 2

During October 1976, the Viking 2 orbiter acquired approximately 700 high-resolution images of the north polar region of Mars. These images confirm the existence at the north pole of extensive layered deposits largely covered over with deposits of perennial ice. An unconformity within the layered deposits suggests a complex history of climate change during their time of deposition. A pole-girdling accumulation of dunes composed of very dark materials is revealed for the first time by the Viking cameras. The entire region is devoid of fresh impact craters. Rapid rates of erosion or deposition are implied. A scenario for polar geological evolution, involving two types of climate change, is proposed.

Science↗
USGS1974

Viking rover studies

Intensive study of Mariner 9 data has resulted in an understanding--although far from complete--of the geologic processes affecting the Martian surface and of its history of development. The results are briefly summarized in the following section. The second section consists of geologic studies of four widely separated areas on Mars (figure 1) selected to provide as wide a variety of environments as possible. For each area a detailed geologic map of a high resolution Mariner 9 B-frame was made and several exemplary traverses were plotted to show how the various geologic units might be visited, sampled, and analyzed. In each area 5 to 10 geologic units appear to be accessible. A substantial fraction of each area is covered by loess-like or dune-like units or channel deposits. That is, there are extensive deposits of transported debris that may be strongly sorted by sedimentational processes. However a variety of indigenous rocks are also present in each of the areas selected. Volcanic rocks of several types and impact debris occur locally. These are masked to varying degrees by the transported debris. Two additional capabilities are necessary beyond those available for Viking '75. The first is a decrease in the size of the landing ellipse so the spacecraft can be put down close to a desirable landing point. The second is a mobility system to allow exploration in the vicinity of the landing point in order to sample the various units locally present more effectively.

Open-File Report↗
USGS1972

Preliminary mariner 9 report on the geology of Mars

Mariner 9 pictures indicate that the surface of Mars has been shaped by impact, volcanic, tectonic, erosional and depositional activity. The moonlike cratered terrain, identified as the dominant surface unit from the Mariner 6 and 7 flyby data, has proven to be less typical of Mars than previously believed, although extensive in the mid- and high-latitude regions of the southern hemisphere. Martian craters are highly modified but their size-frequency distribution and morphology suggest that most were formed by impact. Circular basins encompassed by rugged terrain and filled with smooth plains material are recognized. These structures, like the craters, are more modified than corresponding features on the Moon and they exercise a less dominant influence on the regional geology. Smooth plains with few visible craters fill the large basins and the floors of larger craters; they also occupy large parts of the northern hemisphere where the plains lap against higher landforms. The middle northern latitudes of Mars from 90 to 150† longitude contain at least four large shield volcanoes each of which is about twice as massive as the largest on Earth. Steep-sided domes with summit craters and large, fresh-appearing volcanic craters with smooth rims are also present in this region. Multiple flow structures, ridges with lobate flanks, chain craters, and sinuous rilles occur in all regions, suggesting widespread volcanism. Evidence for tectonic activity postdating formation of the cratered terrain and some of the plains units is abundant in the equatorial area from 0 to 120° longitude.Some regions exhibit a complex semiradial array of graben that suggest doming and stretching of the surface. Others contain intensity faulted terrain with broader, deeper graben separated by a complex mosaic of flat-topped blocks. An east-west-trending canyon system about 100–200 km wide and about 2500 km long extends through the Coprates-Eos region. The canyons have gullied walls indicative of extensive headward erosion since their initial formation. Regionally depressed areas called chaotic terrain consist of intricately broken and jumbled blocks and appear to result from breaking up and slumping of older geologic units. Compressional features have not been identified in any of the pictures analyzed to data. Plumose light and dark surface markings can be explained by eolian transport. Mariner 9 has thus revealed that Mars is a complex planet with its own distinctive geologic history and that it is less primitive than the Moon.

Icarus↗
USGS1972

Photogeology: Part W: Apollo 16 landing site: summary of Earth-based remote sensing data

The purpose of the infrared (IR) and radar study of the Apollo data is to establish lunar surface conditions in the vicinity of the orbital tracks of the Apollo command modules during the J-series missions. Correlations and comparisons between the Earth-based radar observations, IR observations, and other data will be plotted on photomaps produced from the mapping and panoramic cameras. In addition, the Apollo photography will be used to improve the classifications of the anomalous IR and radar features. The three sets of Earth-based data have already been obtained. The IR (11 μm) data (ref. 29-112) were obtained during a total lunar eclipse. More than a thousand thermally anomalous regions with an unusually high population of exposed boulders have been identified (ref. 29-113). The 70-cm radar backscatter observations made at the same resolution as the IR measurements show regions of anomalous backscatter. These regions have been explained as roughness caused by the boulders on the surface and below the surface. The high-resolution 3.8-cm radar backscatter measurements (ref. 29-114) reveal in great detail regions of anomalous radar backscatter. At this short radar wavelength, small-scale surface and subsurface roughness and boulders less than the order of 10 cm are responsible for the anomalous returns. Previous studies have revealed strong correlation between these three data sets (refs. 29-115 to 29-117). The strongest anomalies (anomalous at all three wavelengths) correspond to features interpreted geologically as young Copernican craters. There are, however, many combinations of enhancements from IR only, 70-cm radar only, 3.8-cm radar only, or combinations of two of these types but not a third. The variation of intensity in all combinations indicates a very complex set of features. These data provide information about the surface on a centimeter- and meter-sized scale although the basic instrumental resolution was 2 to 15 km. The Apollo orbital photography and observations at the landing sites, used in conjunction with the remote sensing data, can significantly improve geologic and geophysical interpretations of lunar surface conditions.

Book chapter↗
USGS1968

Geologic map of the Ptolemaeus Quadrangle of the moon

The Ptolemaeus quadrangle is near the center of the lunar disk , in the northern part of the southern highlands . Smooth dark maria border the quadrangle on the west and north, but most of the area is complex, highly cratered terra.

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USGS1968

Chapter 9: Theory and processes relating to the lunar maria from the surveyor experiments

Prior to the Surveyor missions, there were three principal theories about the chemical constitution of the lunar maria: that the maria were (1) chondritic, (2) basaltic, or (3) silicic. Three types of materials recovered on Earth were suspected of coming from the maria: (1) chondritic meteorites, (2) basaltic achondrites, and (3) tektites. The Surveyor chemists have now spoken: Turkevich, Franzgrote, and Patterson find that, in Mare Tranquillitatis (ref. 9-1) and Sinus Medii (see ch. 7 of this report), the composition is basaltic. It is unmistakably too poor in magnesium to be like either kind of chondritic meteorite. It is too rich in the heavier elements, iron and calcium, to resemble terrestrial silicic rocks (the granitic kindred) or tektites.

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