The putative occurrence of methane in the Martian atmosphere has had a major influence on the exploration of Mars, especially by the implication of active biology. The occurrence has not been borne out by measurements of atmosphere by the MSL rover Curiosity but, as on Earth, methane on Mars is most likely in the subsurface of the crust. Serpentinization of olivine-bearing rocks, to yield hydro...

Wray, S. L. Murchie, B. L. Ehlmann, R. E. Milliken, K. D. Seelos, E. Z. Noe Dobrea, J. F. Mustard, and S. W. Squyres, Department of Astronomy, Cornell University, Ithaca, NY 14853, USA ([email protected]), JHU/Applied Physics Lab, Laurel, MD, USA, IAS/Univ. Paris, Orsay, France, Univ. Notre Dame, Notre Dame, IN, USA, Planetary Science Institute, Tucson, AZ, USA, Brown Univ., Providence, R...

Geochemical models for Mars predict carbonate formation during aqueous alteration. Carbonate-bearing rocks had not previously been detected on Mars' surface, but Mars Reconnaissance Orbiter mapping reveals a regional rock layer with near-infrared spectral characteristics that are consistent with the presence of magnesium carbonate in the Nili Fossae region. The carbonate is closely associated w...

Carbonates are key minerals for understanding ancient Martian environments because they are indicators of potentially habitable, neutral-to-alkaline water and may be an important reservoir for paleoatmospheric CO2. Previous remote sensing studies have identified mostly Mg-rich carbonates, both in Martian dust and in a Late Noachian rock unit circumferential to the Isidis basin. Here we report e...

Reconnaissance geologic investigations by I.L. Tailleur in 1968 noted the presence of widespread iron-oxide staining in creek beds in the Wulik River and Ikalukrok Creek drainages of the western Brooks Range. A brief examination of one of these creeks revealed the presence of weathered sulfide-bearing bedrock and stream sediments containing more than 10 percent lead (Tailleur, 1970). Tailleur n...

the dehno granite massive is located in the east dehno village and southern khomein city and within themetamorphic sanandaj–sirjan zone. the composition of these rocks include: granodiorite, quartzdiorite(tonalite), monzogranite and leucogranite. quartz, alkali feldspar, plagioclase, biotite, andalusite, hornblendemuscovite, tourmaline, zircon and apatite are examples of the existing major and ...

Charnockitic rocks form extensive orthogneiss plutons in many granulite terranes and are less commonly found in unmetamorphosed plutons, which have formed in various tectonic regimes. Geochemically, clearly igneous charnockites cover nearly the whole range of granite chemistry, from magnesian to ferroan and from calcic to alkalic. Pyroxenes from unmetamorphosed charnockitic rocks have compositi...

melt fractions that percolated pervasively throughout the massif and On the basis of their structural and compositional characteristics, had a refractory, calc-alkaline character. Locally, these melts were mafic rocks in the Ronda peridotite are classified into four groups: tapped into cracks forming intrusive dykes. group A (garnet-bearing rocks) occurring in the spinel tectonite domain; group...