The composition of the silicate portion of Martian regolith fines indicates derivation of the fines from mafic to ultramafic igneous rocks, probably rich in pyroxene. Rock types similar in chemical and mineralogical composition include terrestrial Archean basalts and certain achondrite meteorites. If these igneous rocks weathered nearly isochemically, the nontronitic clays proposed earlier as a...

Introduction: The 52±6 ka old Lonar crater, India [1, 2], is the only known terrestrial impact crater in basaltic target-rocks (Deccan Traps, ~65 Ma). The impactor asteroid of this ~1.8 km diameter crater was perhaps a chondrite [3] that hit the pre-impact surface from east at an angle of 30-45 o with horizon [4]. Presently, we report the possible distribution of impact-induced stress around Lo...

We report a new radiometric Rb–Sr age determination of 4.0370.04 Ga for high-Al basaltic clast 14321,1353, which is a Group B Apollo 14 high-Al basalt based on its whole-rock incompatible-traceelement chemistry. In addition, available literature Rb–Sr isotope data for Apollo 14 high-Al basalts were reprocessed using the same decay constant and data reduction protocol as used for sample 14321,13...

Deep Sea Drilling Project Leg 75 drilled into igneous basement in the Angola Basin at Site 530, located about 20 km north of the escarpment at the eastern end of the Walvis Ridge. Petrographic and geochemical characteristics of the basalts indicate that the basement is quite uniform, variations in chemical composition being related to weathering, crystal fractionation, and the modal abundances ...

Analyses by the Mars Exploration Rover (MER), Spirit, of Martian basalts from Gusev crater show that they are chemically very different from terrestrial basalts, being characterized in particular by high Mgand Fe-contents. To provide suitable analog basalts for the International Space Analogue Rockstore (ISAR), a collection of analog rocks and minerals for preparing in situ space missions, espe...

The rubidium-strontium isotopic relationships in alkaline and subalkaline oceanic basalts have been determined by mass spectrometric techniques. The results are consistent with a complex model for the earth in which there is continuing convection. Sr87/Sr 8 6 ratios for all oceanic basalts fall in a narrow range from .702 to .705. This suggests that the oceanic upper mantle source regions are g...

[1] We acquired new thermal emission spectra of oxidized synthetic Martian meteorite-like basalts for comparison to Martian surface spectra acquired by the Mars Global Surveyor Thermal Emission Spectrometer (MGS TES). We find that true thermal emission spectra of the oxidized basalts do not provide good spectral matches to the Martian spectra. By contrast, previous biconical reflectance spectra...

Introduction: Luna 16 landed on the northeastern corner of Mare Fecunditatis on September 20, 1970. The robotic mission returned to Earth with a drill core that sampled the regolith to a depth of 35cm. This core was replete with relatively high-Al mare basalts (11-20 wt% Al2O3 compared to typical mare basalts: 7-11 wt% Al2O3). The return of these samples raised two important questions: does Mar...