mineral paragenesis of rodingitized basic rocks of iranian ophiolites are presented and metasomatic reactions between ca+2 bearing aqueous fluids issued during serpentinization of host ultramafic rock – with magmatic minerals of basic rocks leading to present paragenesis of rodingites are discussed. it is concluded that ca+2 rich aqueous fluid in equilibrium with serpentinite has high ca+2 chem...

The production of hydrogen and methane by geochemical reactions associated with the serpentinization of ultramafic rocks can potentially support subsurface microbial ecosystems independent of the photosynthetic biosphere. Methanogenic and methanotrophic microorganisms are abundant in marine hydrothermal systems heavily influenced by serpentinization, but evidence for methane-cycling archaea and...

New mapping, geochronology, and geochemistry of the supracrustal enclave and associated orthogneisses at Akilia, West Greenland, support a >3825 6 Ma age for the sequence and a chemical sedimentary origin for the controversial Fe-rich quartz-pyroxene gneisses. Lithologies of the enclave comprise laterally continuous, mappable units of mafic amphibolite, ultramafic rocks, and two Fe-rich quartzp...

Abu Hamamid (AH) Neoproterozoic (Sm/Nd model age of 770 ± 20 Ma) mafic–ultramafic intrusion lies along a NE–SW fracture zone in the Shadli Metavolcanic Belt, south Eastern Desert, Egypt. AH intrusion is concentrically zoned with cumulate clinopyroxenebearing dunite core mantled by olivine clinopyroxenite, hornblende clinopyroxenite and hornblende gabbroic rim. The observed crystallization seque...

Introduction: In the search for life on Mars nearsurface soil environments may be important habitats for life accessible to future missions. Serpentinite rocks have been documented on Mars [1], as well as other clay minerals including smectite and kaolinites [2, 3]. Previous studies of soils formed on serpentinites on Earth have documented the formation of extensive clays, including smectite [4...

New Caledonia is known for the diversity of its geological substrates, which have shaped highly original and diverse flora. Here, effect soil on vegetation described several contact zones between ultramafic other substrates. The main formations soils derived from rocks are described: low medium altitude rainforests, high maquis. types maquis biological characteristics species also presented.

Serpentine is formed during chemical transformation of ultrabasic magmatic rocks. The characteristics of serpenti ne soi l are its high Mg and low Ca contenI. Various factors have lead to the formation of specific serpentine flora and vegetation. In the serpentine flora both basophi10us and acidophilous plant species are present, and a small number of families and often genera predominate. Most...

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...