Studies of subsurface microorganisms have yielded few environmentally relevant isolates for laboratory studies. In order to address this lack of cultivated microorganisms, we initiated several enrichments on sediment and underlying basalt samples from North Pond, a sediment basin ringed by basalt outcrops underlying an oligotrophic water-column west of the Mid-Atlantic Ridge at 22°N. In contras...

Abstract Ocean-island basalts (OIBs) are considered to be messengers from the deep mantle, yet filtering effect of plumbing systems that bring OIB melts surface remains poorly assessed. We investigated volcanic products El Hierro island (Canary Islands) textural and chemical perspectives. The majority geochemical data cluster at relatively fractionated basaltic compositions 5 wt% MgO. Compositi...

[1] Low-angle subduction of oceanic lithosphere may be an important process in modifying continental lithosphere. A classic example is the underthrusting of the Farallon plate beneath North America during the Laramide orogeny. To assess the relevance of this process to the evolution and composition of continental lithosphere, the mantle stratigraphy beneath the Mojave Desert was constrained usi...

[1] Rough topography on the ocean floor is a source of ocean mixing which is of interest to both physical oceanography and climate science. Most mixing has been attributed to high slopes of the large-scale structures of the deep ocean floor such as seamounts, continental margins, and mid-ocean ridge axes. In this paper, we show the small-scale but ubiquitous abyssal hills and fracture zones dom...

Abstract Oceanic core complexes (OCCs) and detachment faults play a key role in crustal accretion at slow ultraslow spreading centers. We investigated the effect of different magma supply three OCCs Southwest Indian Ridge using high-resolution deep-sea bathymetric magnetic data. The average equivalent thickness extrusive basalt deduced from anomalies, proxy for supply, decreases west to east, Y...

Introduction: Mars’ basaltic crust has been altered by H2O to form hydrated silicates (mostly clays) that are distributed globally [1,2] and extend to great depth [3]. However, climate models for early Mars are challenged to generate warm and wet environments needed to form these minerals via weathering near or at the surface [4,5], and geomorphic evidence for surface hydrology seems to postdat...

Some workers have held that mid-ocean ridge basalts are fractionated from high pressure (15-30 kbar) picritic primary magmas whereas others have favored primary magmas generated at about 10 kbar with compositions close to those of mid-ocean ridge basalts. Of critical significance are presumed differences in composition between experimentally determined primary magmas and the least fractionated ...

The results of our combined U–Pb, Rb–Sr, and Sm–Nd isotope study of mare basalt 10017 contribute to the understanding of the petrogenetic processes involved in the origin of geochemical diversity in lunar mare basalt sources, as well as the U–Pb isotope systematics of the Moon. The Rb–Sr, Sm–Nd, and U–Pb isotope systems yield concordant crystallization ages of 3.633 ± 0.057 Ga, 3.678 ± 0.069 Ga...