Tenoumer crater, Mauritania - Age and petrologic evidence for origin by meteorite impact
Tenoumer crater meteorite impact origin from shock metamorphic features analysis
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Tenoumer crater meteorite impact origin from shock metamorphic features analysis
Shock metamorphic granular mafic holocrystalline lithic fragments, microbreccia, glass and anorthosite from Apollo 11 lunar surface material at Tranquillity Base
Lunar rocks petrography, mineralogy and petrogenesis from Apollo 11 samples
Comparing geological relationships between various rock strata of Iceland and Mid-Atlantic Ridge
Investigating mineral composition of Apollo 11 and 12 lunar rock samples
Electron microprobe analysis of fine-grained igneous rocks from lunar sample 10022 from Sea of Tranquillity
Electron probe microanalysis of minerals of lunar igneous rocks from Apollo 11 flight
Apollo 15 mission and manned geologic exploration of lunar landing site - maps
Apollo 11 lunar soil sample derived from basaltic and anorthositic rocks, considering basalt origin by melting due to internal radioactive heating
Petrographic microscope and electron microprobe analysis of Apollo 12 rock 12013, noting bimineralic composition with dominant potassic feldspar plus silica
Mesosiderites silicate textures and compositions and metal-silicate relationships from mineralogical, petrographical and chemical data
Lunar maria igneous rock compositions and magmatic liquid viscosity from samples 12021 and 12022, using microprobe analyses
Apollo 11 and 12 crystalline rocks petrographical analysis and textural-mineralogical-chemical group classification, considering local stratigraphy reconstruction
Melting experiments over the pressure range 0 to 20 kilobars were conducted on Apollo 14 igneous rocks 14310 and 14072 and on comprehensive fines 14259. The mineralogy and textures of rocks 14310 and 14072 are presumed to be the result of near-surface crystallization. The chemical compositions of the samples show special relationships to multiply-saturated liquids in the system: anorthite-forsterite-fayalite-silica at low pressure. Partial melting of a lunar crust consisting largely of plagioclase, low calcium pyroxene, and olivine, followed by crystal fractionation at the lunar surface is proposed as a mechanism for the production of the igneous rocks and soil glasses sampled by Apollo 14.
A total number of 1858 lithic and vitreous fragments from the Luna 16 core-tube sample are classified. The fragments were taken from soil fractions ranging in size from 150 to 425 microns at levels A and G. No important differences are observed between the proportions of particle types in levels A and G, nor between the soils of Luna 16 and those from the Apollo 11 landing site in the nearby Mare Tranquillitatis.
Basaltic rocks, hyaloclastites, and fossil fragments incorporated in volcanic material, dredged from the flanks of Northeast Bank on the Southern California Borderland, show trace element abundances typical of eastern Pacific basin alkali basalts but enriched (880 ppm) Ba. The fossil fragments, incorporated in breccia, hyaloclastite, and agglomerate, include a fauna which lived in less than 50 m of water, as well as forms from the intertidal zone. Bathymetry of the bank and the depth range of the dredged zone indicate that there has been at least 300 or as much as 500 m subsidence since the volcanism which incorporated the fauna in volcanic material. Isostatic adjustments due to crustal load of the bank can account for this subsidence.
Extensive microprobe analyses have been made of pyroxenes, plagioclases, olivines, opaque minerals, and glasses in two 0.025 g lunar samples returned from the Luna 16 mission, with the aim to characterize the Mare Fecunditatis regolith. No major differences were found between the near surface soil horizon A and horizon D at approximately 30 cm depth. Resulting characteristics of the mineral examined are presented and discussed.
Basaltic and monomineralic fragments from the 150-425 micron size fractions of the Luna 16 core obtained from the Sea of Fertility were studied by optical petrographic, electron microprobe, and single-crystal X-ray diffraction techniques. Three textural varieties were identified in the basalts (intersertal, subophitic, and recrystallized). These textures, the assemblages, and individual mineral compositions (especially pyroxenes) indicate that these basalts crystallized under conditions very similar to those from Apollo 11. The pyroxenes have slightly lower Ti/Al (atomic) ratios than the Apollo 11 pyroxenes. We interpret the presence of octahedral Al as being due to the low TiO2/Al2O3 (weight %) ratio in the bulk rock. All observations made on the fine-grained basalt fragments are consistent with a rapid, near-surface, one-stage crystallization history.