Bitumens associated with lead,zinc and flnorite ore minerals in North Derbyshire,England

A bitumen deposit in north Derbyshire, England, is described and studied using the techniques of gas chromatography, infra-red spectrophotometry and elemental analysis. The bitumens are associated with lead-zinc-fluorite ore minerals concentrated along an unconformable contact between the Carboniferous Limestone and the overlying shales. Three varieties of bitumen are distinguished and are compared with the dispersed bitumens in both the Carboniferous Limestone and the Edale Shales, with crude oils believed to be derived from these shales, and with inclusions in the hydrothermal mineral fiuorite, associated with the limestone-shale contact. One of the varieties recognized, a brittle brown solid, contains aliphatic hydrocarbons very similar to those of the shales and to those of the crude oils likely derived from these shales. The other two are a viscous oil and a brittle, black solid, which geologic evidence suggests were originally derived from the limestone. They contain a very complex mixture of aliphatic hydrocarbons quite different from those in the limestone, however. Aliphatic hydrocarbons isolated from fluorite, which is hydrothermally formed, in nearby massive deposits are almost identical to those of the limestone and shale. This observation indicates that alteration of the aliphatic hydrocarbons in the sediment by hydrothermal fluids is an unlikely explanation for the origin of the complex mixtures of hydrocarbons in the viscous oil and brittle, black solid. On the basis of indirect evidence of high nitrogen content, presence of unsaturated hydrocarbons, and suitability of the environment for bacterial growth, it is suggested that selective bacterial alteration of the aliphatic hydrocarbons is the main process responsible for their present composition. A geologic history for the deposit is postulated that involves a two-phase introduction of bitumens. Each phase is suggested to have begun as a pulse of warm saline fluids migrating along the shale-limestone unconformity passed through the topographic high at Windy Knoll. Microbial oxidation of the bitumens may have taken place during the deposition process or, more likely, as a recent secondary oxidation process.     

MAROS: a decision support system for optimizing monitoring plans

The Monitoring and Remediation Optimization System (MAROS), a decision-support software, was developed to assist in formulating cost-effective ground water long-term monitoring plans. MAROS optimizes an existing ground water monitoring program using both temporal and spatial data analyses to determine the general monitoring system category and the locations and frequency of sampling for future compliance monitoring at the site. The objective of the MAROS optimization is to minimize monitoring locations in the sampling network and reduce sampling frequency without significant loss of information, ensuring adequate future characterization of the contaminant plume. The interpretive trend analysis approach recommends the general monitoring system category for a site based on plume stability and site-specific hydrogeologic information. Plume stability is characterized using primary lines of evidence (i.e., Mann-Kendall analysis and linear regression analysis) based on concentration trends, and secondary lines of evidence based on modeling results and empirical data. The sampling optimization approach, consisting of a two-dimensional spatial sampling reduction method (Delaunay method) and a temporal sampling analysis method (Modified CES method), provides detailed sampling location and frequency results. The Delaunay method is designed to identify and eliminate redundant sampling locations without causing significant information loss in characterizing the plume. The Modified CES method determines the optimal sampling frequency for a sampling location based on the direction, magnitude, and uncertainty in its concentration trend. MAROS addresses a variety of ground water contaminants (fuels, solvents, and metals), allows import of various data formats, and is designed for continual modification of long-term monitoring plans as the plume or site conditions change over time.     

Coral recruitment onto an experimental pulverised fuel ash-concrete artificial reef

An experimental artificial reef was deployed in December 1993 at Hoi Ha Wan Marine Park, Hong Kong. This is the first study documenting natural scleractinian coral recruitment onto a stabilised pulverised fuel ash (PFA)-concrete artificial reef. Visible recruits were first recorded 9-10 months after the placement of reef blocks, i.e., in the autumn of 1994. Two scleractinians, Oulastrea crispata and Culicia japonica, were recruited. The recruit density of the former was much greater than the latter. The spatial recruitment pattern of the corals was observed to be affected by the orientation of the attaching surface. O. crispata settled predominantly on the undersides of the reef blocks. There was an edge effect on O. crispata recruitment. C. japonica, however, had a preference for exposed surfaces. O. crispata did not show a preference for block composition whereas C. japonica favoured blocks with high (75% by volume) PFA levels. This shows that PFA-concrete is a potential substratum for artificial reef construction, especially when such reefs aim at rehabilitating corals.     

Biofouling confounds the uptake of trace organic contaminants by semi-permeable membrane devices (SPMDs)

The outer layers of layflat, low density polyethylene plastic tubing (the principal component of semi-permeable membrane devices, SPMDs) were biofouled at a clean site in Hong Kong coastal waters for periods of 1–4 weeks. Following pre-fouling, triolein was added to the SPMDs and, along with control (unfouled) devices, they were exposed to a range of organochlorine pesticides (-HCH, aldrin, p,p^′-DDT) and PAHs (anthracene, fluoranthene and benzo(a)pyrene) under laboratory conditions. Results showed that the uptake of contaminants by SPMDs was severely reduced by as much as 50% under fouling conditions in comparison to unfouled controls. The ultimate utility of SPMDs as passive monitors is thus reduced, although alternative measures, such as the use of permeability reference compounds may compensate, and allow for realistic evaluations of dissolved environmental concentrations in aquatic environments. However, due to the complexities involved in such procedures––especially as they need to be conducted on a case-by-case basis––the utility of SPMDs appears to be limited for estimates of bioavailability unless necessary calibrations are undertaken within each environment that the sampler is used.     

Microbial ecology of the stratified water column of the Black Sea as revealed by a comprehensive biomarker study

The stratified water column of the Black Sea is partitioned into oxic, suboxic, and euxinic zones, each characterized by different biogeochemical processes and by distinct microbial communities. In 2003, we collected particulate matter by large volume in situ filtration at the highest resolution to date for lipid biomarker analysis and bacterioplankton for enumeration of major prokaryotic groups. Abundances of several prokaryotic groups were estimated using CARD-FISH probes specific for Bacteria, Archaea (Crenarchaeota and Euryarchaeota), epsilonproteobacteria (mainly sulfide oxidizers) and sulfate reducing bacteria. We also measured a wide range of bacterial and archaeal lipid biomarkers. Depth distributions of diagnostic biomarkers are matched with zonation of microbial processes, including aerobic bacterial oxidation of methane, oxidation of ammonium by bacteria and archaea, metal reduction, and sulfide oxidation at the chemocline, and bacterial sulfate reduction and anaerobic oxidation of methane by archaea in the anoxic zone. Cell densities for archaea and sulfate reducing bacteria are estimated based on water column biomarker concentrations and compared with CARD-FISH results.     

An analysis of Apollo lunar soil samples 12070,889, 12030,187, and 12070,891: Basaltic diversity at the Apollo 12 landing site and implications for classification of small‐sized lunar samples

Lunar mare basalts provide insights into the compositional diversity of the Moon's interior. Basalt fragments from the lunar regolith can potentially sample lava flows from regions of the Moon not previously visited, thus, increasing our understanding of lunar geological evolution. As part of a study of basaltic diversity at the Apollo 12 landing site, detailed petrological and geochemical data are provided here for 13 basaltic chips. In addition to bulk chemistry, we have analyzed the major, minor, and trace element chemistry of mineral phases which highlight differences between basalt groups. Where samples contain olivine, the equilibrium parent melt magnesium number (Mg#; atomic Mg/[Mg + Fe]) can be calculated to estimate parent melt composition. Ilmenite and plagioclase chemistry can also determine differences between basalt groups. We conclude that samples of approximately 1–2 mm in size can be categorized provided that appropriate mineral phases (olivine, plagioclase, and ilmenite) are present. Where samples are fine‐grained (grain size <0.3 mm), a “paired samples t‐test” can provide a statistical comparison between a particular sample and known lunar basalts. Of the fragments analyzed here, three are found to belong to each of the previously identified olivine and ilmenite basalt suites, four to the pigeonite basalt suite, one is an olivine cumulate, and two could not be categorized because of their coarse grain sizes and lack of appropriate mineral phases. Our approach introduces methods that can be used to investigate small sample sizes (i.e., fines) from future sample return missions to investigate lava flow diversity and petrological significance.     

A petrological,mineralogical, and chemical analysis of the lunar mare basalt meteorite LaPaz Icefield 02205, 02224, and 02226

Abstract— LaPaz Icefield (LAP) 02205, 02226, and 02224 are paired stones of a crystalline basaltic lunar meteorite with a low‐Ti (3.21–3.43% TiO₂) low‐Al (9.93–10.45% Al₂O₃), and low‐K (0.11–0.12% K₂O) composition. They consist mainly of zoned pyroxene and plagioclase grains, with minor ilmenite, spinel, and mesostasis regions. Large, possibly xenocrystic, forsteritic olivine grains (<3% by mode) contain small trapped multiphase melt inclusions. Accessory mineral and mesostasis composition shows that the samples have experienced residual melt crystallization with silica oversaturation and late‐stage liquid immiscibility. Our section of LAP 02224 has a vesicular fusion crust, implying that it was at one time located sufficiently close to the lunar surface environment to have accumulated solar‐wind‐implanted gases. The stones have a comparable major element composition and petrography to low‐Ti, low‐Al basalts collected at the Apollos 12 and 15 landing sites. However, the LAP stones also have an enriched REE bulk composition and are more ferroan (Mg numbers in the range of 31 to 35) than similar Apollo samples, suggesting that they represent members of a previously unsampled fractionated mare basalt suite that crystallized from a relatively evolved lunar melt.