Reviews

A. Barker and F. Manji, Writing for Change ‐ An Interactive Guide to Effective Writing, Writing for Science, Writing for Advocacy, CD‐ROM and Users Guide, Fahama/International Development Research Centre, Oxford, 2000. ISBN: 0–9536–9021–0, no price given. Softback (28 pages) and CD‐ROM

9. Alteration of Uppermost Lavas and Volcaniclastics Recovered During Leg 152 to the East Greenland Margin

During the last stages of the eruption of syn-rift basalts along the East Greenland Margin, debris flows and/or pyroclastic deposits were emplaced at Ocean Drilling Program Sites 915 and 916. The deposits and the tops of the lava flows at Site 918 were altered by subaerial weathering processes as indicated by downhole changes in mineral and chemical composition, and by the mineral paragenesis. Kaolinite and goethite, which form in acidic waters, are abundant at the tops of the weathering profiles and decrease in abundance downward. They are replaced by a smectite-hematite-opal assemblage at the bases of the weathered profiles. Gibbsite is a minor component in the upper parts of the profiles. Good preservation of parent structure and stratification indicate that only the bases of paleosols are preserved at all sites. The upper parts were probably eroded when these sites subsided below sea level. Abundant gibbsite in marine sediment overlying the paleosols and of middle to late Eocene age is probably derived from the erosion of highly weathered soils formed in a subtropical to tropical climate. A highly weathered basaltic terrane supplied abundant iron oxides in addition to gibbsite, kaolinite, illite/mica, and quartz through fluvially dominated deltaic systems on the shelf through at least the late Eocene. Only small amounts of sediment spilled over into the adjacent Irminger Basin through the Eocene, as indicated by the presence of felsic terrane-derived minerals (quartz, illite, and/or mica). Sedimentation rates were low enough in the Irminger Basin to allow Mn oxide crusts to develop until quartzose turbidites spilled over in the late Oligocene. Gibbsite was not detected in sediment of early Oligocene age and younger, suggesting a regional cooling, increased aridity, and/or leveling of the source area at this time

9. Alteration of Uppermost Lavas and Volcaniclastics Recovered During Leg 152 to the East Greenland Margin

During the last stages of the eruption of syn-rift basalts along the East Greenland Margin, debris flows and/or pyroclastic deposits were emplaced at Ocean Drilling Program Sites 915 and 916. The deposits and the tops of the lava flows at Site 918 were altered by subaerial weathering processes as indicated by downhole changes in mineral and chemical composition, and by the mineral paragenesis. Kaolinite and goethite, which form in acidic waters, are abundant at the tops of the weathering profiles and decrease in abundance downward. They are replaced by a smectite-hematite-opal assemblage at the bases of the weathered profiles. Gibbsite is a minor component in the upper parts of the profiles. Good preservation of parent structure and stratification indicate that only the bases of paleosols are preserved at all sites. The upper parts were probably eroded when these sites subsided below sea level. Abundant gibbsite in marine sediment overlying the paleosols and of middle to late Eocene age is probably derived from the erosion of highly weathered soils formed in a subtropical to tropical climate. A highly weathered basaltic terrane supplied abundant iron oxides in addition to gibbsite, kaolinite, illite/mica, and quartz through fluvially dominated deltaic systems on the shelf through at least the late Eocene. Only small amounts of sediment spilled over into the adjacent Irminger Basin through the Eocene, as indicated by the presence of felsic terrane-derived minerals (quartz, illite, and/or mica). Sedimentation rates were low enough in the Irminger Basin to allow Mn oxide crusts to develop until quartzose turbidites spilled over in the late Oligocene. Gibbsite was not detected in sediment of early Oligocene age and younger, suggesting a regional cooling, increased aridity, and/or leveling of the source area at this time

Fluid and electrolyte losses associated with working/exercising for prolonged periods in thermally stressful environments

Fluid and electrolyte disturbances, prompted by high sweat losses, can occur when a person is exposed to harsh environmental conditions for prolonged periods. In the endurance athlete this will have detrimental effects on performance, while in manual labourers the consequent neural and muscular deficits will place an individual’s health at risk as well as increasing the risk of workplace accidents. This research will seek to further explore fluid and electrolyte losses in these two ‘at risk’ populations enabling more appropriate guidelines for replacement to be made

“Something Would’ve Been Better Than Nothing”: An Analysis of Young Adults’ Stories of Being Ghosted

Utilizing the Narrative Paradigm (Fisher, 1984) and thematic analysis (Braun & Clarke, 2006), the present study seeks to explore and analyze stories of being ghosted from the perspective of young adults and to identify the themes that may animate these experiences. Recorded qualitative interviews with 21 young adults who had previously been ghosted resulted in 4 emergent themes: a) justifications b) confusion over responsibility c) avoiding future vulnerability and d) contribution of technology. Findings are consistent with previous research concerning ghosting and attachment theory, destiny beliefs, implicit theories of relationships, the role of technology, and more. Directions for future research and limitations of the present study are discussed

The emerging use of magnetic resonance imaging to study river bed dynamics

The characterization of surface and sub-surface sedimentology has long been of interest to gravel-bed river researchers. The determination of surface structure is important as it exerts control over bed roughness, near-bed hydraulics and particle entrainment for transport1. Similarly, interpretation of the sub-surface structure and flow is critical in the analysis of bed permeability, the fate of pollutants and maintaining healthy hyporheic ecology 2.For example, many invertebrates (e.g. mayfly, caddis) and fish (e.g. salmon) lay their eggs below the river bed surface, and rely on sub-surface flows to supply the necessary oxygen and nutrients. Whilst turbulent surface flows drive these small sub-surface flows, they can also convey sand and silts that clogs the surface and sub-surface pore spaces. Reduction in sub-surface flows can starve eggs of oxygen such that larvae or juveniles do not emerge. This is particularly critical in Scottish gravel-bed rivers as the rising supply and deposition of fine sediment (silts and sands) is contributing to the dramatic decline in wild salmon. In order to gain a better understanding of such flow-sediment-ecology interactions in river systems, laboratory experiments are conducted using long rectangular flow tanks called “flumes”, see figure 1a,1b. Here, traditional techniques for analysing sediment structure are typically constrained to 1D or 2D approaches, such as coring, photography etc. Even where more advanced techniques are available (e.g. laser displacement scanning), these tend to be restricted to imaging the surface of the sediment bed. Using Magnetic Resonance Imaging (MRI) overcomes these limitations, providing researchers with a non-invasive technique with which to provide novel 3D spatio-temporal data on the internal pore structure. In addition the important sub-surface flows can be investigated by adding MRI contrast agents to the flowing surface water

Initial Transgressive Phase of Leg 144 Guyots: Evidence of Extreme Sulfate Reduction

The initial transgressive phase at the Leg 144 Guyots is characterized by a typical association of sedimentary facies (from bottom to top): in situ weathered volcanic rocks; variegated clays, partly pyritic; gray clay, pyritic, homogeneous, or mottled; black clay, peaty, laminated, or bioturbated; and marine argillaceous limestone. Site 877 at Wodejebato Guyot represents the typical development of the initial transgressive phase. The black clay is rich in organic carbon (up to 40%) and sulfur (up to 25%). The organic matter is dominantly of terrestrial origin, but it has a significant marine, algal input. The variegated clays consist of a red, lower, sulfur-free part and a blue to gray-blue, sulfur-containing upper part. Organic carbon is not observed in this facies. The sulfur occurs as pyrite and organically bound sulfur. The isotope composition of pyrite varies from -50‰ to 0%e, which clearly points to bacterial sulfate reduction as the origin for the high sulfur content. Pyrite formation was limited by availability of reactive iron. Because of the origin of the clays as lateritic weathering products, the amount of reactive iron was high, and pyritization proceeded to high values. The following model is suggested for sulfur enrichment in the sediments at the initial transgressive phase: (1) marine flooding of an organic-rich back-reef mangroval swamp; (2) intense bacterial reduction of marine sulfate within the black clay; and (3) downward diffusion of H2S into the underlying clays, reduction of red iron oxides to blue-gray iron sulfides, and growth of pyrite