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At least 127 records · Page 7Linked to original sources
USGS1969

(RLC-14) Geologic map of the Alphonsus region of the moon

This 1:250,000- scale geologic map is one of a series prepared largely from photographs transmitted by Ranger IX (reproduced in a report by Jet Propulsion Lab., 1966). It depicts the geology of the crater Alphonsus (in which Ranger IX impacted) and environs. The primary objective of the mapping was to apply extant lunar mapping techniques used on relatively small scale telescopic photographs to the larger scale Ranger photographs, in preparation for extensive analysis of Lunar Orbiter photography in support of the Apollo program. An additional objective was to shed more light on the formation of Alphonsus and its associated features. The map outlines rock units that are inferred from surface features and characteristics, such as topography and albedo. Each rock unit is assigned an age and arranged in the explanation so that the youngest unit are at the top and the oldest at the bottom. The age classification is based on the early work of Shoemaker and Hackman (1962), and subsequent revisions reported by McCauley (1967) and Wilhelms (1966). Geology of the region has been mapped at a scale of 1:1,000,000 on the basis of Earth-based photographs and observations (Howard and Masursky , 1968). A more detailed, 1;50,000-scale map of part of the Alphonsus floor was prepared by McCauley (1969), who used Ranger IX photographs as his source of geologic information.

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USGS1969

(LAC-24) Geologic map of the Sinus Iridum quadrangle of the moon

The Sinus I ridum quadrangle includes the northwestern sector of Mare I mbrium , the Sinus I ridu m embayment, the arcuate Montes Jura which partly surround Sinus I ridum , and several terra islands in the mare such as the Montes Teneriffe , Montes recti, and C. Herschel * . Mare imbrium occupies a c omple x depression or basin consisting of an inner basin and several outer concentric troughs separated by raised rings ( H artmann and Kuiper, 1962). The center and much of the inner basin , p art of the first raised ring, and part of the first trough lies within the quadrangle. The terra islands are exposed parts of the first r aised ring, which is approximately 670 km in diam eter. Sinus Iridum embays a simpler and smaller structure, a crater 250 km in diameter (herein referred to as the Iridum crater) whose partly exposed rim crest is the Montes Jura. Mare ridges overlie buried parts of the Imbrium ring and the Iridum crater rimcrest (fig. 1).

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USGS1970

(ORB II-2 (100)) Geologic map of the Maskelyne DA region of the moon, Lunar Orbiter site II P-2, southeastern Mare Tranquillitatis including Apollo landing site l

This map shows the geology in and around potential early Apollo landing site 1 in the lunar equatorial belt. The Maskelyne DA region, at the southeastern edge of the Mare T ranquillitatis , is in the area transitional between mare and terra. Patches of typical terra material occur on northwest-trending ridges , and typical heavily cratered mare materials occurs only in the east-central part of the region. The terrain in the rest of the region, including the potential landing site, is exceptionally smooth and deficient in craters more than 50 m (meters) in diameter. A large cratered dome, possibly indicative of late-stage volcanism , o ccurs in the southern part of the region. Telescopically, the terrain over most of the region resembles that of mare areas with intermediate albedo; hence, at a scale of 1:1,000,000 the materials here were mapped as unit Ipm2 of the Procellarum Group ( Wilhelms , 1965).

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USGS1969

(ORB II-13 (100)) Geologic map of the Maestlin G region of the moon, Lunar Orbiter site II P-13, Oceanus Procellarum, including Apollo landing site 5

This map shows the geology in and around potential early Apollo landing site 5 in the lunar equatorial belt. The Maestlin G region is in Oceanus Procellarum, about midway between the crater Kepler to the northeast and Flamsteed to the southwest. Terra materials occur only in the northeast corner of the region. Dark mare covers the remainder, and the entire region is crossed by rays from Kepler. The general geology of the larger Kepler region was mapped at a scale of 1:1,000,000 from telescopic photography (Hackman, 1962), and a 1:25,000 geologic map has been prepared of the landing site in the central part of the region (Titley and Trask, 1969).

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USGS1971

Geologic map of the Wichmann CA region of the Moon, Lunar Orbiter Site III P-11, Oceanus Procellarum including Apollo landing sites 4 and 4R

This map shows the geology in and around two potential early Apollo landing sites in the equatorial belt. The Wichmann CA region is in the Oceanus Procellarum, south of the equator, approximately 320 km south of the crater Kepler. It is covered by mare material with numerous ridges, low domes, craters, and crater clusters. Relatively few of the craters are larger than 200 m across. Terra material is absent. The relative freshness of the low domes and prominent mare ridges suggest that the mare material here is relatively young. On an earlier, small-scale reconnaissance geologic map of the Letronne region (Marshall, 1963), mare material in the Wichmann CA region was mapped as Imbrian; but Orbiter photographs show that the oldest craters on the surface are relatively young Eratosthenian craters and mare material is now believed to be Eratosthenian.

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USGS1972

Geologic map of the Flamsteed K region of the Moon (Lunar Orbiter site III P-12, Oceanus Procellarum)

The Flamsteed K region is in the southern part of Oceanus Procellarum , approximately 60 km (kilom eters) north of the crater Flamsteed and 330 km southwest of the crater Kepler. The region was photographed by Lunar Orbiters I and III ; it includes the landing site of Surveyor I and a potential early Apollo landing site. The area is included in a 1:1,000,000-scale map by Marshall (1962).

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USGS1971

Geologic map of the Lansberg P region of the Moon Lunar Orbiter Site III P-9, Oceanus Procellarum including Apollo landing site 7 (Apollo 12)

The Lansberg P region lies within a lowland area between Mare Cognit um and the main part of Oceanus Procellarum , about 135 km due south of the crater Reinhold. The Apollo 12 landing site is in the west-central part of the region and has been mapped in detail by Cannon (1969) . Although the entire region is covered by cratered and rayed mare materials, the mare is almost entirely surrounded by the terrae and is probably relatively thin . Superposed on the mare are two rays from the crater Copernicus, many individual craters, and crater clusters.

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USGS1971

Geologic map of the Sabine EB region of the Moon

Th e Sabin EB region is a rolling plain which consists entirely of crater and mare materials. The areal density of craters, th ough variable within the region, is sufficiently high so that the craters are the dominant morphological feature. Crater morphology ranges from bright , s harp - rimmed craters to pan-shaped depressions. Superposition relations indicate that the bright-rimmed craters (unit br ) are youngest and that such craters are degraded in time to sha llow, subdued depressions (unit sr ) and presumably to total destruction . It appears that the bright rim deposits , characteristics of the youngest craters, darken with time until their albedo is the same as that of the surrounding material (as in the unit dr ) . Degradation of crater rims probably is caused by superposed crater rims probably is caused by superposed impacts, burial by ejecta from more distant younger craters, and downslope movement of surficial materials. A few craters (unit d) have complex -upward walls which appear to have formed by inward slumping late in the degradation process.

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USGS1971

Geologic map of the Rheita Quadrangle of the Moon

Photographs returned by unmanned Lunar Orbiters have contributed greatly to the current lunar geologic mapping program. This is particu larly true for quadrangles near the limbs, such as Rh eita in the southeast earthside quadrant. The new data and revised in terpretations amend the geologic framework established by earlier workers (Shoemaker (1962) and Shoemaker and Hackman (1962) applied basic stratigraphic principles to set up a lunar time scale; McCauly (1967) summarized changes made in he next five years of study; Wilhelms (1970) compiled all the telescopic refinements and additions to the original framework) . Detailed studies of crater morphologies from Lunar Orbiter photographs ( Pohn and Offield , 1970) permit the placement of most craters within the time- stratigraphic systems ( Offield and Pohn , 1970 : Offield , 1971). Other advances in understanding lunar processes included establishing the sequence of formation and features of large, multiringed basins ( McCauly , 1968; Stuart-Alexander and Howard, 1970) and criteria for distinguishing between impacts and possible volcanic craters (McCauly,1968).

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USGS1972

Geologic map of the Maurolycus Quadrangle of the Moon

The Maurolycus quadrangle , located in the southeastern highlands, includes densely to moderately cratered terrain with many craters larger than 45 km in rim crest diameter . Several appea r to be ancient and may be among the most primitive discernable features on the lunar surface. Major stratigraphic units consist of the Janssen Formation, hummocky terra and pitted plains materials, and e xtensive clusters of bowl-shaped craters. Two of these units, hummocky terra and pitted plains , a re probably volcanic whereas the Janssen Formation and bowl-shaped craters appear t o have been formed by ejecta from the multi-ringed Nectaris and Imbrium basins outside the quadrangle.

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USGS1972

Geologic map of the Clavius Quadrangle of the Moon

The Clavius quadrangle is in the southern lunar highlands about 500 km south of the Mare Nubium and 150 km south of the large young crater Tycho. This part of the M oon is characterized by densely cratered topography and the absence of mare materials. Geologic units in the quadrangle cannot be directly correlated with those in the vicinity of Mare Imbrium , 2500 km to the north, which define most of the lunar time-stratigraphic systems (Shoemaker and Hackman, 1962 ; Wilhelms , 1970). However, the relative ages of rock units, including crater materials, have been determined by established geologic methods, such as superposition and cross-cutting relations. In addition, crater materials have been positioned within the lunar time stratigraphic framework ( Offield , 1971) by estimates. Based on morphology, of their state of erosion ( Pohn and Offi e ld , 1970).

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