Relationships between basin architecture, basin closure, and occurrence of sulphide-bearing schists: an example from Tampere Schist Belt, Finland

We present field observations from the Palaeoproterozoic volcano-sedimentary Tampere palaeobasin, where the primary structures have been exceptionally well preserved. We use the observations to construct a new tectonic model for the southeastern margin of the Tampere basin during its inversion and subsequent closure. The observed volcano-sedimentary and structural features suggest a change in the local structural style from thick-skinned inversion to thin-skinned thrusting, in order to accommodate the crustal shortening during basin closure. Furthermore, it is suggested that there is a genetic relationship between the interpreted palaeothrust and the sulphide-bearing schist horizons in the study area. On a more general note, the results infer that presently subvertical mineralised shear zones may have originally been gently dipping, further suggesting that the mineralised fluids may not necessarily have been sourced from great depths (i.e. from deep within the basement)

Particulate matter from both heavy fuel oil and diesel fuel shipping emissions show strong biological effects on human lung cells at realistic and comparable in vitro exposure conditions

Background: Ship engine emissions are important with regard to lung and cardiovascular diseases especially in coastal regions worldwide. Known cellular responses to combustion particles include oxidative stress and inflammatory signalling. Objectives: To provide a molecular link between the chemical and physical characteristics of ship emission particles and the cellular responses they elicit and to identify potentially harmful fractions in shipping emission aerosols. Methods: Through an air-liquid interface exposure system, we exposed human lung cells under realistic in vitro conditions to exhaust fumes from a ship engine running on either common heavy fuel oil (HFO) or cleaner-burning diesel fuel (DF). Advanced chemical analyses of the exhaust aerosols were combined with transcriptional, proteomic and metabolomic profiling including isotope labelling methods to characterise the lung cell responses. Results: The HFO emissions contained high concentrations of toxic compounds such as metals and polycyclic aromatic hydrocarbon, and were higher in particle mass. These compounds were lower in DF emissions, which in turn had higher concentrations of elemental carbon (“soot”). Common cellular reactions included cellular stress responses and endocytosis. Reactions to HFO emissions were dominated by oxidative stress and inflammatory responses, whereas DF emissions induced generally a broader biological response than HFO emissions and affected essential cellular pathways such as energy metabolism, protein synthesis, and chromatin modification. Conclusions: Despite a lower content of known toxic compounds, combustion particles from the clean shipping fuel DF influenced several essential pathways of lung cell metabolism more strongly than particles from the unrefined fuel HFO. This might be attributable to a higher soot content in DF. Thus the role of diesel soot, which is a known carcinogen in acute air pollution-induced health effects should be further investigated. For the use of HFO and DF we recommend a reduction of carbonaceous soot in the ship emissions by implementation of filtration devices

A geostatistical approach to analyzing gold distribution controlled by large-scale fault systems – An example from Côte d’Ivoire

Geostatistical approaches can help to understand the general characteristics of an area, to suggest feasible geological models, and to quantify overall patterns in the occurrence of economic mineralisation. We use such an approach to demonstrate the relationships between large-scale faults of various ages and kinematics, lithologies, and gold mineralisation to facilitate understanding of crustal-scale structural controls of gold deposits. Our example comes from Côte d’Ivoire, which is known to have undergone at least three major phases of deformation, two of which produced transpressional faults resulting from ESE-WNW and, later, NE/ENE-SW/WSW, compression. Using aeromagnetic and surface geological data, we interpret these faults and suggest a multiphase Riedel model for the region, taking fault reactivation into consideration. With the help of this simplified model, the spatial relationships between the faults, lithology, and 909 known gold occurrences, including 554 artisanal mining sites, are analysed within a GIS. Using geostatistical methods, gold mineralisation was found to probably be a two-stage process, with the later D2 stage potentially being the peak mineralization event. Gold occurrences are most abundant within c. 3 km of both newly formed and reactivated NE-SW faults, most importantly P1 and Y2 faults, in areas of low-intermediate fault density, and close to lithological contacts within the greenstone sequences

An introduction to geological mapping of our world and others

We are indebted to the reviewers who graciously gave their time and expertise in providing feedback to the authors of papers included in this volume, and those that didn’t make the cut. Geoff Lloyd is thanked for providing the images of PHN1611 and discussions on the evolution of EBSD methods. Phoebe Sleath is thanked for providing the scene from her virtual outcrop of the Spitzhorn folds.Peer reviewe

PT-conditions of deformation within the Palaeoproterozoic South Finland shear zone: Some geothermobarometric results

Four rock samples were collected from the crustal-scale South Finland shear zone in order to compare PT-conditions of deformation between gneissose and mylonitic rock types. Two of the samples were collected from a garnet-bearing gneiss representing an early ductile shearing phase. The two other samples were collected from a 30-meter-wide ultramylonite zone; first sample representing the ultramylonite and the second sample a less deformed amphibole-rich gneiss lens within the zone, interpreted to be the mylonite protolith. The new GBPQ geobarometer and the Gt-Bt exchange geothermometer were applied to the two garnet-bearing samples. The temperature conditions of the ultramylonites and the gneissose protolith were compared with the amphibole-plagioclase thermometer by Holland and Blundy (1994). The transpressive ductile shearing that produced the granodioritic and tonalitic gneisses within the study area is interpreted to have taken place in conditions with minimum metamorphic peaks at approximately 680 °C and 7 kbar as indicated by the GBPQ barometer and Gt-Bt thermometer. The results of the Hbl-Plg thermometry, based on the ultramylonite and amphibole gneiss data, suggest that the ultramylonite was formed at minimum 50 °C lower temperature conditions than the surrounding gneisses (the uncertainty of the Hbl-Plg thermometer is 35-40 °C). This is consistent with field observations of a large-scale reactivation of the shear zone after the main transpressive phase of the late stages of the Svecofennian orogen in Southern Finland

Comparison of dissolution methods for multi-element analysis of some plant materials used as bioindicator of sulphur and heavy metal deposition determined

Most analytical methods for trace element determination in plant material require decomposition of the sample. Sample decomposition procedures play an important role in ensuring that chemical analysis gives correct results. This is especially important in the determination of trace elements in plant material for environmental studies because, as a rule, plant material is not homogeneous and usually contains variable matrices. In this paper microwave digestion procedures using HNO$_3$, HNO$_3$+H$_2$O$_2$, HNO$_3$+HClO$_4$, HF mixtures and dry ashing + HF were investigated for the analysis of Al, Ca, Cr, K, Mg, Mn, Zn, S, Pb, V, Cu, Cd, Co and Ni by ICP-AES or ICP-MS from pine needle samples. Reference samples BCR CRM 100 (Spruce Needles), BCR CRM 101 (Beech Leaves) and HUMH2 (Organic surface soil) were used to test the dissolution methods. The results showed that the sample digestion procedure is critical step for obtaining accurate results. Losses of volatile metals were notable in many cases when dry ashing was used

Effective density and morphology of particles emitted from small-scale combustion of various wood fuels

The effective density of fine particles emitted from small-scale wood combustion of various fuels were determined with a system consisting of an aerosol particle mass analyzer and a scanning mobility particle sizer (APM-SMPS). A novel sampling chamber was combined to the system to enable measurements of highly fluctuating combustion processes. In addition, mass-mobility exponents (relates mass and mobility size) were determined from the density data to describe the shape of the particles. Particle size, type of fuel, combustion phase, and combustion conditions were found to have an effect on the effective density and the particle shape. For example, steady combustion phase produced agglomerates with effective density of roughly 1 g cm(-3) for small particles, decreasing to 0.25 g cm(-3) for 400 nm particles. The effective density was higher for particles emitted from glowing embers phase (ca. 1-2 g cm(-3)), and a clear size dependency was not observed as the particles were nearly spherical in shape. This study shows that a single value cannot be used for the effective density of particles emitted from wood combustion