A sedimentological study of diamondiferous Quaternary sediments in Southern Shandong,China

A sedimentological study of the lower Quaternary sediments in southern Shandong Province suggests that they were derived from a northern highland area of Archaean gneiss and Palaeozoic sediments. Diamond-bearing kimberlites, intruded during the Ordovician, occur in the highland area and are a possible source of diamonds found in the Quaternary sediments. A warm and humid climate prevailed at the beginning of the Quaternary and braided rivers carried gravel and sand southeast towards the Yellow Sea. Cooler and drier conditions in Q2 times reconcentrated diamonds from the underlying Q1 gravels. Post-Q2 faulting deflected the drainage to the south and subsequent erosion left only small remnants of diamondiferous Q2 gravel. A study of diamond shape characteristics suggests that the diamonds in the Quaternary sediments were derived from the known kimberlites to the north, although the possibility of undiscovered kimberlites occurring beneath the Quaternary sediments cannot be ruled out.     

Setting a size-exclusion limit to remove toxic dinoflagellate cysts from ships' ballast water

Dinoflagellate cysts are well-recognized biological constituents of ships' ballast tanks. They are present in ballast water, sediments and residual water in drained tanks, and in biofilms formed on interior tank surfaces. Therefore, cysts have the potential to be released during ballast discharge. The International Maritime Organization's (IMO) Ballast Water Management Convention (promulgated February 2004) stipulates a performance standard (Annex, Regulation D2) requiring discharged ballast water contain <10 viable organisms between 10 and 50 microm per ml and <10 viable organisms 50 microm per m3. The proposed size limit has potential to exclude both the smallest toxic and the largest toxic and non-toxic dinoflagellate (and other microalgal) cysts from discharged ballast water. Despite the appropriateness of size cutoffs however, ballast water containing predominantly small cysts (<50 microm) could be deemed in compliance with the performance standard, even without treatment, while ballast water having the same concentration of larger cysts (>50 microm) could require a multiple-log reduction in abundance before its permissible discharge. Also of concern, it remains uncertain whether ballast-water treatment can remove sufficient organisms, including dinoflagellate cysts, to meet the performance standard.     

Potential climatic transitions with profound impact on Europe

We discuss potential transitions of six climatic subsystems with large-scale impact on Europe, sometimes denoted as tipping elements. These are the ice sheets on Greenland and West Antarctica, the Atlantic thermohaline circulation, Arctic sea ice, Alpine glaciers and northern hemisphere stratospheric ozone. Each system is represented by co-authors actively publishing in the corresponding field. For each subsystem we summarize the mechanism of a potential transition in a warmer climate along with its impact on Europe and assess the likelihood for such a transition based on published scientific literature. As a summary, the ‘tipping’ potential for each system is provided as a function of global mean temperature increase which required some subjective interpretation of scientific facts by the authors and should be considered as a snapshot of our current understanding.     

Identifying biologically and physically special or unique sites for inclusion in the protected area design for the Great Barrier Reef Marine Park

A method to identify special and/or unique sites was developed when reviewing the zoning of the Great Barrier Reef Marine Park. Fifty-three (totalling approximately 10,445 km²) of 408 sites were identified as special or unique based on the amount, detail and nature of justification; geographic explicitness; type of information sources; number of independent sources; and national or international obligations. All but four special or unique sites increased in protection after the Zoning Plan was revised, increasing the area of no-take protection for all special or unique sites from 1614 km² (15.4%) to 4013 km² (38.4%).     

Impact of Climate Change on <Emphasis Type="Italic">Vibrio vulnificus</Emphasis> Abundance and Exposure Risk

Vibrio species are marine bacteria that occur in estuaries worldwide; many are virulent human pathogens with high levels of antibiotic resistance. The average annual incidence of all Vibrio infections has increased by 41% between 1996 and 2005. V. vulnificus (Vv), a species associated with shellfish and occurring in the US Southeast, has ranges of temperature (16–33 °C) and salinity (5–20 ppt) dependencies for optimal growth. Increased water temperatures caused by atmospheric warming and increased salinity gradients caused by sea level rise raise concerns for the effect of climate change on the geographic range of Vv and the potential for increased exposure risk. This research combined monthly field sampling, laboratory analysis, and modeling to identify the current occurrence of Vv in the Winyah Bay estuary (South Carolina, USA) and assess the possible effects of climate change on future geographic range and exposure risk in the estuary. Vv concentrations ranged from 0 to 58 colony forming units (CFU)/mL, salinities ranged from 0 to 28 ppt, and temperature from 18 to 31 °C. A significant empirical relationship was found between Vv concentration and salinity and temperature that fit well with published optimal ranges for growth for these environmental parameters. These results, when coupled with an existing model of future specific conductance, indicated that sea level rise has a greater impact on exposure risk than temperature increases in the estuary. Risk increased by as much as four times compared to current conditions with the largest temporally widespread increase at the most upriver site where currently there is minimal risk.     

Unraveling the Schneeberg garnet puzzle: a numerical model of multiple nucleation and coalescence

A quantitative kinetic model for the growth of the different garnet porphyroblast microstructures (type 1 and type 2) of the Western Schneeberg Complex (WSC) is presented. These porphyroblasts formed by a multiple nucleation and coalescence mechanism. Our numerical simulation shows that at constant diffusion rates: (1) low interface reaction rates result in a fully amalgamated porphyroblast (type 2); (2) intermediate reaction rates result in a porphyroblast, where coalescence of grains closer to the margin prevented amalgamation of those in the centre (similar to type 1 porphyroblasts); and (3) high interface reaction rates result in a porphyroblast microstructure with an atoll form. All three microstructures are characterised by distinctive cluster size distributions. A 2-D cluster size distribution analysis of type 1 porphyroblasts of WSC shows that these did not form because of intermediate interface reaction rates, but because the diffusion rate of nutrients was too low to keep pace with the interface reaction rate.Editorial responsibility: T.L. Grove     

GeoReM: A New Geochemical Database for Reference Materials and Isotopic Standards

We have developed a new database named GeoReM ( http://georem.mpch-mainz.gwdg.de ) for reference materials and isotopic standards of geochemical and mineralogical interest. Reference samples include rock powders originating from the USGS, GSJ, GIT-IWG, synthetic and natural reference glasses originating from NIST, USGS, MPI-DING, as well as mineral (e.g., 91500 zircon), isotopic (e.g., La Jolla, E&A, NIST SRM 981), river water and seawater reference materials. GeoReM is a relational database, which strongly follows the concept of the three EARTHCHEM databases. It contains published analytical and compilation values (major and trace element concentrations, radiogenic and stable isotope ratios), important metadata about the analytical values, such as uncertainty, uncertainty type, method and laboratory. Sample information and references are also included. Three different ways of interrogating the database are possible: (1) sample names or material types, (2) chemical criteria and (3) bibliography. Some typical applications are described. GeoReM currently (October 2005) contains more than 750 geological reference materials, 6000 individual sets of results and references to 650 publications.     

Chemical Characterisation of the USGS Reference Glasses GSA-1G, GSC-1G, GSD-1G, GSE-1G, BCR-2G, BHVO-2G and BIR-1G Using EPMA, ID-TIMS, ID-ICP-MS and LA-ICP-MS

The USGS reference glasses GSA-1G, GSC-1G, GSD-1G, GSE-1G, BCR-2G, BHVO-2G and BIR-1G were investigated by different analytical techniques. All these materials have a geological (basaltic) matrix and are therefore useful in igneous geochemistry as matrix-matched reference materials for microanalytical techniques. The new GS glasses have trace elements in groups at concentration levels of about < 0.01, 5, 50 and 500 μg g^-1. Their major element compositions have been determined by EPMA, and trace elements have been analysed by LA-ICP-MS and two isotope dilution techniques using TIMS and ICP-MS. EPMA and LA-ICP-MS analyses indicated that the USGS reference glasses are homogeneous at the μm to mm scale with respect to major (variations < 1-2%) and most trace elements (variations 1-4%). Trace element data obtained from the different analytical techniques agreed within an uncertainty of 1-5%, indicating that between method results are comparable. Therefore, the preliminary working values for the four USGS GS glasses calculated from these data have a low level of uncertainty.     

Caught in the Currents: Pollution,Risk, and Environmental Change in Marine Space

Human interactions with the marine environment and pollution hold broad lessons for understanding environmental change. Expanding geographical inquiry beyond its traditional, land-based foci and delving deeper into marine environment and risk issues offers fruitful avenues by which to elaborate and refine our understanding of nature-society relationships. I present a case study of marine petroleum transportation risks in the Straits of Malacca to illustrate the complex history of political and economic processes across a range of scales and shaping the risks in the Straits. The inescapable tension between generalizing global social and environmental processes and recognizing the array of local differences drives ongoing policy debates in the Straits, as it does increasingly for many global environmental problems.