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Stoeser, D. B.

Publications and source records attributed to Stoeser, D. B..

Notes on Lithology, Mineralogy, and Production for Lunar Simulants

The creation of lunar simulants requires a very broad range of specialized knowledge and information. This document covers several topic areas relevant to lithology, mineralogy, and processing of feedstock materials that are necessary components of the NASA lunar simulant effort. The naming schemes used for both terrestrial and lunar igneous rocks are discussed. The conflict between the International Union of Geological Sciences standard and lunar geology is noted. The rock types known as impactites are introduced. The discussion of lithology is followed by a brief synopsis of pyroxene, plagioclase, and olivine, which are the major mineral constituents of the lunar crust. The remainder of the text addresses processing of materials, particularly the need for separation of feedstock minerals. To illustrate this need, the text includes descriptions of two norite feedstocks for lunar simulants: the Stillwater Complex in Montana, United States, and the Bushveld Complex in South Africa. Magnetic mineral separations, completed by Hazen Research, Inc. and Eriez Manufacturing Co. for the simulant task, are discussed.

Rickman, D. L.↗

Preliminary Geological Findings on the BP-1 Simulant

A waste material from an aggregate producing quarry has been used to make an inexpensive lunar simulant called BP-1. The feedstock is the Black Point lava flow in northern Arizona. Although this is part of the San Francisco volcanic field, which is also the source of the JSC-1 series feedstock, BP-1 and JSC-1 are distinct. Chemically, the Black Point flow is an amygdaloidal nepheline-bearing basalt. The amygdules are filled with secondary minerals containing opaline silica, calcium carbonate, and ferric iron minerals. X-ray diffraction (XRD) detected approximately 3% quartz, which is in line with tests done by the Kennedy Space Center Industrial Hygiene Office. Users of this material should use appropriate protective equipment. XRD also showed the presence of significant halite and some bassanite. Both are interpreted to be evaporative residues due to recycling of wash water at the quarry. The size distribution of BP-1 may be superior to some other simulants for some applications.

Stoeser, D. B.↗

Development of Lunar Highland REgolith Simulants, NU-LHT-1M,-2M

As part of a collaborative agreement between the U.S, Geological Survey (USGS) and NASA's Marshall Space Flight Center (MSFC) lunar highland simulants are being produced to support engineers and scientists in developing the technologies required to put a base on the moon by 2024. Two simulants have been produced to date: NU-LHT-1M and -2M (NASA/USGS-Lunar Highlands Type-l & 2 Medium-grained). Using starting material chiefly collected from the Stillwater Mine, Nye, MT, blending protocols were developed based on normative mineralogy calculated from average chemistry, for the Apollo 16 regolith. New technologies using a high temperature remotely coupled plasma melter were developed to generate both high quality and agglutinitic glasses that simulate the glassy components of the regolith. Detailed chemical, mineralogical and physical properties analysis of NU-LHT-1M indicate that it is overall a good surrogate for highlands lunar regolith (our new simulant LHT-2M has not be analyzed yet). The primary difference between 1M and 2M was the inclusion of trace mineralogy (phosphates and sulfide). Plans will also be presented on the future direction of the simulant project.

Stoeser, D. B.↗

Apollo 17 KREEPy basalt - A rock type intermediate between mare and KREEP basalts

The Apollo 17 KREEPy basalt is a unique lunar volcanic rock, observed only as clasts in the light friable breccia matrix (72275) of Boulder 1, Station 2 at Taurus-Littrow. Its status as a volcanic rock is confirmed by the absence of any meteoritic contamination, a lack of cognate inclusions or xenocrystal material, and low Ni contents in metal grains. The basalt was extruded 4.01 + or - 0.04 b.y. ago, approximately contemporaneously with the high-alumina mare basalts at Fra Mauro; shortly afterwards it was disrupted, probably by the Serenitatis impact, and its fragments emplaced in the South Massif. The basalt, which is quartz-normative and aluminous, is chemically and mineralogically intermediate between the Apollo 15 KREEP basalts and the high-alumina mare basalts in most respects. It consists mainly of plagioclase and pigeonitic pyroxene in approximately equal amounts, and 10-30% of mesostatis.

Ryder, G.↗

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.↗

Petrology

Boulder 1 as a whole can be considered a complex polymict breccia consisting of lithic and breccia clasts seated in a matrix that ranges from friable and poorly sintered to densely welded. Only two of the four samples collected from boulder 1, Station 2 have been examined in detail: 72255 and 72275. Of the remaining two, only two undocumented thin sections from 72235 have been studied, while none from 72215 has been examined. Sample 72275 was collected as representative of the boulder matrix, whereas the other three samples were thought to be large clasts.

Stoeser, D. 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.↗