The age and origin of the quartz-amphibole-pyroxene (qap) gneiss from the island of Akilia, southern West Greenland, have been the subject of intense debate since the light C-isotope composition of graphite inclusions in apatite was interpreted to indicate the presence of Earth's earliest biological activity. Although this claim for biogenic relicts has been vigorously challenged, the possibili...

A new species of skink, Caledoniscincus notialis sp. nov., is described from the ultramafic ranges in southern New Caledonia. It is most similar to, and has previously been referred to Caledoniscincus atropunctatus (Roux), a species with a widespread distribution throughout the Grand Terre and Loyalty Islands. The new species is distinct genetically from all other Caledoniscincus and can be dis...

Particle transport by erosion from ultramafic lands in pristine tropical lagoons is a crucial problem, especially for the benthic and pelagic biodiversity associated with coral reefs. Satellite imagery is useful for assessing particle transport from land to sea. However, in the oligotrophic and shallow waters of tropical lagoons, the bottom reflection of downwelling light usually hampers the us...

Hilary Downes, David W Mittlefehldt, Pierre Hudon, Christopher S. Romanek and Ian Franchi Lunar and Planetary Institute, Houston, Texas, USA ([email protected]); School of Earth Sciences, Birkbeck, University of London, London, UK; NASA/Johnson Space Centre, Houston, Texas, USA; Dept. of Earth and Planetary Sciences, McGill University, Montreal, Quebec, Canada; 5 Savannah River Ecology Labora...

The emission of methane and the higher hydrocarbons is observed in both mid-ocean ridge and subduction-related hydrothermal systems. It has been recently reported that methane emanating from an extensional ultramafichydrothermal system originates from the abiogenic reduction of (mantle) CO2 (1). The same process is also known to occur in subaerial subduction-related systems (2). These findings ...

Chromitites associated with strongly altered peridotite from six distinct localities in the Santa Elena ultramafic nappe (Costa Rica) have been investigated for the first time. Santa Elena chromitites commonly display a compositional variation from extremely chromiferous (Cr/(Cr+Al)=0.81) to intermediate and aluminous (Cr/(Cr+Al)=0.54). This composition varies along a continuous trend, correspo...