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Marvin, U. B.

Publications and source records attributed to Marvin, U. B..

At least 19 records

New observations on the quartz monzodiorite-granite suite

Five new fragments of quartz monzodiorite (QMD) were identified in particles from soil 15403, which was collected from the boulder sampled as rock 15405, an impact-melt breccia containing clasts of KREEP basalt, QMD, granite, and a more primitive alkali norite. Petrographic and geochemical studies of the fragments show considerable variation in modal proportions and bulk composition. This heterogeneity is due to unrepresentative sampling in small fragments of coarse-grained rocks. Variations in the proportions of accessory minerals have marked effects on incompatible-trace-element concentrations and ratios. Semiquantitative calculations support the derivation of QMD from 60-percent fractional crystallization of a KREEP basalt magma as suggested by Hess (1989). Apollo 15 KREEP basalt cannot be the actual parent magma because the evolved rocks predate volcanic KREEP basalts. It is suggested that ancient KREEP basalt magmas have crystallized as plutons, with alkali norite clasts offering the only direct evidence of this precursor.

Marvin, U. B.

Apollo 15 KREEP-poor impact melts

Results are presented on the analysis of 18 fragments of the Apollo 15 KREEP-poor impact melt rock. This melt has gabbroic bulk composition, very low incompatible-element concentrations, and a slope in its heavy REE pattern that is distinct from that of KREEP. The melt has also the highest Ti content of LKFM impact melts from all highland sites. It is suggested that KREEP-poor impact melts may be basin-related melts which are mixtures of various Mg-suite noritic or gabbroic lower crustal rocks, and represent an early impact into the lower crust.

Lindstrom, M. M.

Apollo 15 Mg- and Fe-norites - A redefinition of the Mg-suite differentiation trend

The Apollo 15 highland rocks from the Apennine Front include clasts of mafic plutonic rocks from deep in the lunar crust that were brought to the surface by the Imbrium and Serenitatis impacts. The Apollo 15 norites exhibit wide variations in mineral and bulk compositions and include Fe-norites that plot between the three major pristine rock fields on a diagram of Mg' in mafic minerals vs An in paglioclase. Based on assemblages and compositions of minerals, and on ratios of elemental abundances, it is concluded that these Apollo 15 Fe-norites are differentiated members of the Mg-norite suite. The Apollo 15 and 17 norites and troctolites form a closely related suite of rocks, whose variations in mineral compositions represent the main differentiation trend of the Mg-suite. This trend in mineral compositions has a steeper slope than the previous Mg-suite field. The parent magmas for these Mg-suite rocks formed by partial melting deep in the lunar mantle. Differentiation by fractional crystallization may also have included assimilation of crustal components as the magmas rose from the mantle and crystallized plutons in the lower crust.

Lindstrom, M. M.

A transient heating event in the history of a highlands troctolite from Apollo 12 soil 12033

A 2-mm particle, consisting of a troctolite clast attached to a small amount of glassy soil breccia, was found in a thin section of grains from Apollo 12 sample 12033,66. A description is given of the evolutionary history of the troctolite, taking into account the unique texture. It appears that the particle was broken from its parent rock and projected to Oceanus Procellarum from a source area in the highlands. Before, during, or after the flight, the troctolite was welded to a soil breccia by a minor amount of melting along the contact. It is argued that two separate heating events may be involved. The hypothesis is considered that the partial remelting and quenching of the troctolite took place very rapidly. Attention is given to melting experiments which test and confirm this hypothesis.

Marvin, U. B.

Mineralogical investigations of lunar samples and meteorites

Electron microprobe analysis was employed to study north ray crater breccia 67015 from the Moon. The melting history of lunar troctolite 130-9 was investigated, along with the presence of Mg-26 in anorthite grains recovered from the Vaca Meurta mesosiderite. Geographic distributions of meteorites in Antarctica were plotted. The Allende meteorite was analyzed with the electron microprobe method.

Marvin, U. B.

The discovery and initial characterization of Allan Hills 81005 - The first lunar meteorite

Antarctic meteorite ALHA81005, discovered in the Allan Hills region of Victoria Land, is a polymict anorthositic breccia which differs from other meteorites in mineralogical and chemical composition but is strikingly similar to lunar highlands soil breccias. The petrologic character and several independent lines of evidence identify ALHA81005 as a meteorite from the moon. Two small clasts of probable mare basalt occur among the highlands lithologies in Thin Section 81005,22. This lunar specimen, which shows relatively minor shock effects, has generated new ideas on the types of planetary samples found on the earth.

Marvin, U. B.

Rock 67015 - A feldspathic fragmental breccia with KREEP-rich melt clasts

The feldspathic fragmental breccia (FFB) 67015, from the rim of North Ray Crater, contains a wider range of clast lithologies than have previously been described for FFBs. The present petrological and chemical study reveals two components of major importance: a dark, vesicular, KREEP-rich melt rock of very high alumina basalt composition common at the Apollo 16 site, and a large clast of medium-grained ferroan anorthositic norite which composition falls among the most magnesian members of the ferroan anorthosite suite of pristine cumulate rocks. This latter material constitutes a previously missing member of certain mixing models, which were designed to account for the North Ray Crater melt rocks and bulk breccias.

Marvin, U. B.

A pristine eucrite-like gabbro from Descartes and its exotic kindred

A coarse-grained plagioclase-pyroxene gabbro (61224,6) with a cumulate texture suggestive of a slowly cooled plutonic rock was recovered from the 4-10 mm fraction of an Apollo 16 soil. The rock is uncommonly poor in feldspar and rich in Na for a lunar highlands lithology. Trace element analyses show extremely low siderophile element concentrations which confirm the pristine character indicated by the texture. The composition of 61224,6 is compared with those of 3 other pristine, exceptionally mafic, nonmare gabbros and of certain eucrites. 61224,6 and the three other gabbros have notable chemical differences but share relatively high ratios of Ti/Sm and Sc/Sm which suggest a possible genetic relationship. We conclude that 61224,6 represents a Na-rich cumulate from a layered intrusion within the highlands crust.

Marvin, U. B.

On the origin of Luna 24 basalts and soils

Analyses of fine-grained very low titanium (VLT) basalt from the Luna 24 drill core suggest that a single homogeneous magma is represented by the sample. In particular, the small variation in MgO contents of the fine-grained basalt, together with the tight clustering of the compositions of brown glasses (which may be pyroclastic equivalents of the VLT basalt), provides evidence for the single-magma hypothesis. The high-Mg component in the soil samples, though not obviously explainable in petrographic terms, may be derived from material similar to olivine vitrophyre and its degraded products, or from some other high-Mg VLT basalt.

Ryder, G.

Basalts from Mare Crisium

The stratified core sample returned from Mare Crisium by the Luna 24 unmanned space probe is composed primarily of a variety of subophitic to ophitic basalt with very low contents of TiO2 and MgO. This consists of clinopyroxene, calcic plagioclase, olivine, and minor amounts of silica, chromite, ulvoespinel, ilmenite, troilite, apatite, and Fe-metal. Granular metabasalts have the same bulk composition, but mineral phases exhibit less compositional variation. Fine-grained impact melts have similar compositions and are apparently derived from these basalts. It is concluded that the basalts, which are chemically distinct from the very-low-titanium basalts found elsewhere on the moon, represent the local surface flows of Mare Crisium. Sparse fragments of an olivine vitrophyre that is low in TiO2 but high in MgO and approaches the composition of the Apollo 15 green glasses may be derived from patches of dark mantling materials 20 km from the landing site.

Ryder, G.

The Boulder

The external morphologies of Boulder 1, Station 2, and of the four samples taken from it by the Apollo 17 crew, are briefly described. The boulder is a polymict breccia, containing the following principal materials as clasts: gray competent breccias, black competent breccias, anorthositic breccias, pigeonite basalt, and coarse norite. All are enclosed in a matrix of light-colored friable breccia.

Marvin, U. B.

Boulder 1, Station 2, Apollo 17 - Petrology and petrogenesis

The clasts and matrices of Boulder 1, Station 2 are investigated by petrographic and microprobe methods. The boulder is shown to consist of two separate entities: an older metamorphosed breccia containing a diverse lithic clast population, and a friable matrix containing KREEPy basalts. It is suggested that the friable matrix was created in the Serenitatis event in a cool upper portion of the ejecta blanket and that the clasts were created in an earlier impact event. These results are shown to indicate that the Serenitatis event is younger than 4.01 billion years and that the lunar crust had a complex and varied history of magmatism, metamorphism, and brecciation in the interval between the origin of the moon and the assembly of the boulder.

Ryder, G.

Lunar granites with unique ternary feldspars

An unusually high concentration of granitic fragments, with textures ranging from holocrystalline to glassy, occurs throughout Boulder 1, a complex breccia of highland rocks from Apollo 17, Station 2. Among the minerals included in the granites are enigmatic K-Ca-rich feldspars that fall in the forbidden region of the ternary diagram. The great variability in chemistry and texture is probably the result of impact degradation and melting of a granitic source-rock. Studies of the breccia matrix suggest that this original granitic source-rock may have contained more pyroxenes and phosphates than most of the present clasts contain. Petrographic observations on Apollo 15 KREEP basalts indicate that granitic liquids may be produced by differentiation without immiscibility, and the association of the granites with KREEP-rich fragments in the boulder suggests that the granites represent a residual liquid from the plutonic fractional crystallization of a KREEP-rich magma. Boulder 1 is unique among Apollo 17 samples in its silica-KREEP-rich composition. We conclude that the boulder represents a source-rock unlike the bedrock of South Massif.

Ryder, G.

Morphology and surface mapping

Of the many boulders photographed at the Apollo 17 site, boulder 1 from Station 2 is unique in having a strongly developed foliation. Resistant layers form four steeply inclined ridges separated by joint planes or by deeply eroded beds of softer materials. A prominent cleavage, or set of cross joints, is oriented almost normal to the foliation. The cleavage is expressed as subparallel cracks, some of which are open fissures. The entire surface of the boulder is rough and studded by dark colored knobs ranging in diameter from 1 to 15 cm. It is a polymict breccia containing at least one type of rock that has not been recognized in any other lunar sample, and it records an unusual minor element distribution and magnetic history.

Marvin, U. B.

Appendix A: Specimen 72275 documentation

The friability of the matrix of specimen 72275 caused numerous fragments and an abundance of fines to break away from the main mass during transport from the moon and handling in the lunar receiving laboratory. Samples 72275,1 to 72275,14 were labeled during PET examination. Samples 72275,1, 4, 6, 7, 8, and 9 were placed in storage, and the remainder were distributed.

Marvin, U. B.

Appendix B: Specimen 72255 documentation

Three documented pieces broke away from specimen 72255 during transport. Samples 72255,1 to 72255,9 were assigned numbers during examination, samples 72255,3 to 72255,6 and 72255,9 were placed in storage, and the remainder were distributed.

Marvin, U. B.

Petrology of a stratified boulder from South Massif, Taurus-Littrow

Boulder 1 from Station 2 at the foot of South Massif is unique in being the only stratified boulder sampled by the Apollo 17 astronauts. Our studies of two of the four specimens that were collected from separate layers show that the boulder is composed of glass-poor, fragment-rich breccias which are aggregates of differentially annealed terra material, mainly ANT, but including basaltic troctolite, pigeonite basalt, granitic particles, dark breccia-rimmed anorthositic clasts, and a KREEPless norite that has not been recognized elsewhere at the Apollo 17 site. The boulder appears to derive from the uppermost blue-gray layer on South Massif, which we believe consists of ejecta deposited from a single large impact event (possibly the one which excavated the Serenitatis Basin).

Stoeser, D. B.