The Bransfield Strait is the narrow, late Tertiary to Quaternary marginal basin separating the South Shetland Islands from the northern end of the Antarctic Peninsula magmatic arc. Quaternary volcanism in the strait is tholeiitic to mildly alkaline, and contrasts chemically with the pre-Quaternary calc-alkaline arc volcanism. Geochemical evidence presented here...
Volcanic rocks from hotspots and island arcs/backarcs typically have enriched trace
element and isotopic compositions that contain a contribution from subducted oceanic crust.
Isotopic and trace element data suggest that the enriched components in hotspot volcanism
are ancient subducted sediment and crust, and the enriched components in arc/backarc
volcanism are...
The interaction of basalt melt with mantle harzburgite at low pressure might result in silica enrichment of the melt by assimilation of orthopyroxene. Experimental tests of this hypothesis show that silica-rich liquids (56 wt %) are produced by melt-orthopyroxene reaction at 1200° to 1250°C. These silica-rich liquids are enriched in...
Oceanic crust covers nearly 70% of the Earth's surface, of which, the upper,
sediment layer is estimated to harbor substantial microbial biomass. Marine crust;
however, extends several kilometers beyond this surficial layer, and includes the
basalt and gabbro layers. In particular, the basalt layer has high permeabilities which
allows for...
The subsurface microbial biosphere in the igneous oceanic crust has implications for global geochemical cycling, early life on Earth, and the search for life on Mars. Microscopic evidence of a subsurface microbial ecosystem includes biotic alteration textures associated with basaltic glass. The exact conditions in the basaltic layer that make...
Igneous oceanic crust encompasses ~60% of Earth’s surface and is composed of basalt glass and mafic, ultramafic, and felsic minerals. A vast marine aquifer lies within the crust, exchanging geochemically altered fluids with seawater from the overlying ocean at ridge crests, flanks, seamounts, and outcrops where permeable crust is exposed....
We propose alternative mechanisms for the origin of three unusual rock suites, high-Mg andesites, NaTi basalts, and arclike rocks, that have been dredged from the Woodlark basin, southwest Pacific Ocean. We show that the high-Mg andesites and NaTi basalts are associated with an unusually cool ridge environment. The cooling is...
The myxozoan parasite Ceratonova shasta threatens both juvenile and adult salmonid populations in the Pacific Northwest region of the United States, causing intestine necrosis and hemorrhaging, along with high mortality in some fish strains. It induces an inflammatory tissue response in susceptible strains of fish; understanding the interactions between C....
Wheat (Triticum aestivum L.) is one of the most important crops in the world. It has been and continues to be one of the main sources of food for humans and animals. Although traditional wheat breeding has contributed greatly to the improvement of wheat both in productivity and biotic/abiotic stress...
Chlorinated ethenes are common groundwater contaminants that may be treated through in-situ bioremediation. Relationships between the reducing environment, available electron donors and acceptors, reaction kinetics, and microbial community composition must be further understood to successfully engineer remediation schemes in the complex subsurface environment. This thesis work investigated the effect of...
Fischer-Tropsh Synthesis is a chemical process that converts CO and H₂ (syngas) into long stable hydrocarbon chains to use as fuel. This process suffers from large product distribution that requires expensive post processing. In this study, the reaction mechanism of hydrocarbon chain growth on Co is investigated on different surface...
The objectives of this project were to determine the effects of harvest maturity, packaging, and storage conditions on subsequent fruit quality of Actinidia arguta ‘Ananasnaya’ and to investigate the use of edible coatings to improve fruit quality and storage life. The influences of harvest maturity (6.0, 8.7, 9.1, and 15.1%...
These first measurements of specific surface area (SSA)
of bulk samples of subsurface marine basalts were undertaken
to determine the potential area available for microbial
colonization. SSA ranged from 0.3 to 52 m2/g of basalt
with the lowest value coming from pillow basalt and the
highest value from breccia. The...
Hydrothermal vents appear to be the tip of the subsurface biosphere in the ocean crust. The primary prducers in this biosphere are prokaryotes that tolerate a wide variety of physical and chemical conditions and are versatile in their use of inorganic compounds to drive metabolism. A synthesis of chemical and...
The alteration of subseafloor volcanic glass from three locations is qualitatively attributed to biological
(biotic) or chemical (abiotic) reactions on the basis of microscopic morphology of the boundary between
the unaltered and altered glass. Eleven-element composition of fresh basalt glass (sideromelane) and its
alteration products were determined by electron microprobe....
With rising concentrations of CO₂ in the Earth's atmosphere causing
concern about climate change, many solutions are being presented to
decrease emissions. One of the proposed solutions is to sequester excess
CO₂ in geological formations such as basalt. The deep subsurface is known
to harbor much of the microbial biomass...