Mineralogical Fingerprints Research Articles

Mineralogical fingerprint and human health risk from potentially toxic elements of Fe mining tailings from the Fundão dam

In 2015, >50 million cubic meters of Fe mining tailings were released into the Doce River basin from the Fundão dam, raising the question of its consequences on the affected ecosystems. This study aimed to establish a mineralogical-(geo)chemical association of potentially toxic elements (PTEs) from Fe mining tailings from the Fundão dam, collected seven days after the failure, through a multidisciplinary approach combining assessment of the risk to human health, environmental geochemistry, and mineralogy. Thus, eleven tailings samples were collected with the support of the Brazilian Military Police Fire Department. Granulometry, magnetic measurements, optical microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and sequential chemical extraction of PTEs analyses were performed. Contamination indexes, assessment of risk to human health, and Pearson correlation were calculated using the results of sequential chemical extraction of PTEs. The predominance of goethite in Fe oxyhydroxide concentrates from the mud indicates that the major source of hematite may not be from tailings, but from pre-existing soils and sediments, and/or preferential dissolution of hematite in deep flooded zones of the tailings column of the Fundão dam. Moreover, the high correlation of most carcinogenic PTEs with their crystallographic variables indicates that goethite is the primary source of contaminants. Goethites from Fe mining tailings showed high specific surface area and Al-substitution, and due to their greater stability and reactivity, the impacts on PTE sorption phenomena and bioavailability may be maintained for long periods. However, their lower dissolution rate, and the consequent release of heavy metals would promote greater resilience for affected ecosystems, preventing significant PTE inputs under periodic reduction conditions. More specific studies, involving the crystallographic characteristics of Fe oxyhydroxides should be developed since they may provide another critical component of this set of complex and dynamic variables that interfere with the bioavailability of metals in ecosystems.

Sedimentological and Mineralogical Fingerprint of the Beach Sediments, Western Mediterranean Coast, Egypt

The composition and texture of beach sediments along continental coastlines vary considerably. Beach sands made completely of carbonate sediments are prevalent along Egypt's Western Mediterranean Coast. Forty-five sediment samples were collected from various locations (El-Dekhela, Kilo-21, Abu Talat, and Sidi Krir) along the Western Mediterranean Coast of Egypt. The sedimentological and mineralogical attributes of the collected sediments were investigated using collaborative techniques. The beach sediments in the coastal region between El-Dekhela and Sidi Krir consist mainly of carbonate sands that are mineralogically composed of dolomite, calcite, and aragonite with smaller amounts of quartz, sylvite, anhydrite, gypsum, and trace amounts of microcline. They contain ooids with bioclasts and very few heavy minerals, except for notable amounts of these minerals in the El-Dekhela region. These heavy minerals primarily consist of opaque minerals, amphiboles, and pyroxenes, with smaller amounts of epidote, zircon, tourmaline, rutile, garnet, kyanite, monazite, sphene, staurolite, and biotite. The combination of heavy minerals in these deposits indicates a wide variety of igneous, metamorphic, and sedimentary rock types as potential source rocks. Heavy mineral concentrations decrease westward from the Nile River's mouth near Rosetta to Egypt's Western Mediterranean Coast. Most of the studied ooids are white colored and usually have a pearly luster; these characteristics indicate that these sediments were formed in agitated water. The current study reveals that the ooids in the study area originated from a variety of sources, including autochthonous and allochthonous ooids that eroded and broke, implying that they may have originated from coastal plain carbonate ridges.

Characterization of road surfacing aggregates based on their mineralogical fingerprint

To ensure the safety of infrastructure users, the long-term skid resistance is a crucial factor and is determined in large by the mineralogical and morphological characteristics of surfacing aggregate. Most studies have investigated these aggregate properties separately without considering the interrelation between one another. The objective of this study is to consider the morphological characteristics as well as the mineralogical fingerprint of aggregate to develop an innovative approach to optimize the aggregate selection process. The investigations are based on 11 different aggregate types with a broad range of mineralogy, commonly used in Germany. The long-term influence of polishing and wearing on the surface aggregate was simulated by means of the Aachen Polishing Machine and the Micro-Deval test respectively. To evaluate the impact of these tests, the aggregate shape was characterized by means of an imaging system called Aggregate Image Measurement System while the skid resistance of aggregates was evaluated with the British Pendulum Test. The test results show that the quartz and calcite are the key crystals to determine the anti-wear resistance of aggregates. A correlation between the skid resistance, morphological properties and mineralogy is derived, which proves the mineralogical fingerprint technology is practical for characterization of aggregates used in pavement surface layers. • Long-term influence of polishing and wearing on the surface aggregate is simulated. • Characterizations of the mineralogical fingerprint and morphological parameters of aggregates are determined. • Correlation between skid resistance, morphological properties and mineralogy of aggregates is derived.

The Heavy Mineral Map of Australia: Vision and Pilot Project

We describe a vision for a national-scale heavy mineral (HM) map generated through automated mineralogical identification and quantification of HMs contained in floodplain sediments from large catchments covering most of Australia. The composition of the sediments reflects the dominant rock types in each catchment, with the generally resistant HMs largely preserving the mineralogical fingerprint of their host protoliths through the weathering-transport-deposition cycle. Heavy mineral presence/absence, absolute and relative abundance, and co-occurrence are metrics useful to map, discover and interpret catchment lithotype(s), geodynamic setting, magmatism, metamorphic grade, alteration and/or mineralization. Underpinning this vision is a pilot project, focusing on a subset from the national sediment sample archive, which is used to demonstrate the feasibility of the larger, national-scale project. We preview a bespoke, cloud-based mineral network analysis (MNA) tool to visualize, explore and discover relationships between HMs as well as between them and geological settings or mineral deposits. We envisage that the Heavy Mineral Map of Australia and MNA tool will contribute significantly to mineral prospectivity analysis and modeling, particularly for technology critical elements and their host minerals, which are central to the global economy transitioning to a more sustainable, lower carbon energy model.

Raman microspectroscopy applied to flint provenance at the chalcolithic settlement of Zambujal (Torres Vedras, Portugal)

AbstractThe mineralogical fingerprint of both archaeological and geological flint, measuring by Raman microspectroscopy the α‐quartz, and the minor elements was studied. Quartz crystallinity index, by XRD, was calculated in geological samples. An estimation of the degree of crystallinity through Raman analysis could be used to infer quartz crystallinity in archaeological materials. The evaluation of moganite content allowed a better differentiation among Cenomanian flints from different places. It was possible to confirm the correlation between archaeological microfacies M1‐TV with the Torres Vedras Cenomanian flint and warn that the M2 flint preliminary associated to Lisboa region could be from another source area.

Mineralogical Fingerprint of Iron Ore Tailings in Paraopeba River Bedload Sediments after the B1 Dam Failure in Brumadinho, MG (Brazil)

The study presents SEM-based automated mineralogy to distinguish between natural sediments and iron ore tailings deposits from the Paraopeba River, after the failure of B1 Dam in Brumadinho, Minas Gerais, Brazil. Samples were obtained from borehole cores drilled over channel bars and banks eight months after the failure. After preliminary facies description, sediments from 54 chosen intervals were subjected to density measurement, X-ray diffraction (XRD), SEM-based automated mineralogy (QEMSCAN) analysis and determination of geochemical major components. Hierarchical clustering analysis (HCA) and principal component analysis (PCA) revealed six main mineral associations governed by different contents and ratios of quartz, kaolinite and hematite. Natural sediments are predominantly composed of mineral associations containing kaolinite, quartz and quartz + hematite with density values ranging from 2.5 to 3.3 g/cm3. Tailings deposits have density values higher than 3.5 g/cm3 and are mainly composed of hematite with occasional occurrences of kaolinite + hematite. Because of geological complexity and historical terrain occupation and usage, geochemical anomalies are common in the Paraopeba River sediments. Our data suggests that mineralogical oriented studies should precede detailed geochemical investigations, to enhance the understanding of the source of such anomalies and the environmental jeopardy associated to the occurrence. In this sense, SEM-based mineralogy has an enormous potential in environment studies.

Geochemical Proxies and Mineralogical Fingerprints of Sedimentary Processes in a Closed Shallow Lake Basin Since 1850

Lake systems are essential for the environment, the biosphere, and humans but are highly impacted by anthropogenic activities accentuated by climate change. Understanding how lake ecosystems change due to human impacts and natural forces is crucial to managing their current state and possible future restoration. The high sensitivity of shallow closed lakes to natural and anthropogenic forcing makes these lacustrine ecosystems highly prone to variations in precipitation and sedimentation processes. These variation processes, occurring in the water column, produce geochemical markers or proxies recorded in lake sedimentary archives. This study investigated specific proxies on high-resolution sedimentary archives (2–3 years resolution) of the Trasimeno lake (Central Italy). The Trasimeno lake underwent three different hydrological phases during the twentieth century due to several fluctuations induced mainly by human activities and climate change. The Trasimeno lake, a large and shallow basin located in the Mediterranean area, is a good case study to assess the effects of intense anthropogenic activity related to agriculture, tourism, industry, and climate changes during the Anthropocene. The aim is to identify the main characteristics of the main sedimentary events in the lake during the last 150 years, determining the concentrations of major and trace elements, the amount of organic matter, and the mineralogical composition of the sediments. This type of work demonstrates that studying sediment archives at high resolution is a viable method for reconstructing the lake’s history through the evolution/trends of the geochemical proxies stored in the sediment records. This effort makes it possible to assess past anthropogenic impact and, under the objectives of the European Green Deal (zero-pollution ambition for a toxic-free environment), to monitor, prevent, and remedy pollution related to soil and water compartments.Graphical abstract

Significance of tridymite distribution during cooling and vapor-phase alteration of ignimbrites

Abstract Thick sequences of silicic ignimbrites contain complex emplacement and cooling histories, often masking contacts between ignimbrite flow packages. Mineralogical and textural variations in these sequences are primarily a function of emplacement temperature and cooling time. Here, we focus on the use of the silica polymorph tridymite to understand the association of vapor-phase crystallization and devitrification within ignimbrite flow packages. As opposed to the common occurrence of cristobalite, the restricted domains in which we observe tridymite may provide more relevant constraints for interpreting post-emplacement devitrification and vapor-phase alteration. This study examines sections through the Whakamaru (New Zealand), Bishop (U.S.A.), and Grey’s Landing (U.S.A.) ignimbrites by combining textural observations with measurements of density, groundmass crystallinity, and the distribution and proportion of tridymite to cristobalite. The rheomorphic Grey’s Landing ignimbrite represents a high-temperature end-member scenario, with widely distributed tridymite (up to 20%) resulting from a high-magmatic temperature and rapid devitrification in a low-porosity deposit. In the welded Whakamaru and Bishop ignimbrites, metastable tridymite (up to 13%) is concentrated along boundaries between flow packages. Here tridymite is interpreted to crystallize in transient permeable zones, forming during vapor-phase alteration prior to compaction, where upper denser-welded flow materials serve as vapor seals. Our results suggest that tridymite may link the initial cooling and welding history of ignimbrites to vapor-phase alteration and devitrification, and may serve as a potential mineralogical fingerprint of depositional contacts, important for consideration of lateral transport of fluids in geothermal reservoirs.

The geochemical and mineralogical fingerprint of West Antarctica's weak underbelly: Pine Island and Thwaites glaciers

The marine-based West Antarctic Ice Sheet (WAIS) is considered the most unstable part of the Antarctic Ice Sheet, with particular vulnerability in the Amundsen Sea sector where glaciers are melting at an alarming rate. Far-field sea-level data and ice-sheet models have pointed towards at least one major WAIS disintegration during the Late Quaternary, but direct evidence for past collapse(s) from ice-proximal geological archives remains elusive. In order to facilitate geochemical and mineralogical tracing of the two most important glaciers draining into the Amundsen Sea, i.e. Pine Island Glacier (PIG) and Thwaites Glacier (TG), we here provide the first multi-proxy provenance analysis of 26 seafloor surface sediment samples from Pine Island Bay.Our data show that the fingerprints of detritus delivered by PIG and TG are clearly distinct near the ice-shelf fronts of both ice-stream systems for all grain sizes and proxies investigated. Glacial detritus delivered by PIG is characterised by low εNd values (~−9), high 87Sr/86Sr ratios (~0.728), low smectite content (<10%), and hornblende and biotite grains with Late Permian to Jurassic (170–270 Ma) cooling ages. In contrast, glacigenic detritus delivered by TG is characterised by higher εNd values (~−4), lower 87Sr/86Sr ratios (0.714), higher smectite (20%) and kaolinite content (37%), biotite and hornblende grains with 40Ar/39Ar cooling ages of <40 Ma and ~115 Ma, and high content of mafic minerals.The geochemical and mineralogical fingerprints for PIG and TG reported here provide novel insights into sub-ice geology and allow us to trace both drainage systems in the geological past, under environmental conditions more similar to those envisioned in the next 50 to 100 years.

Exploring Fingerprints of the Extreme Thermoacidophile Metallosphaera sedula Grown on Synthetic Martian Regolith Materials as the Sole Energy Sources.

The biology of metal transforming microorganisms is of a fundamental and applied importance for our understanding of past and present biogeochemical processes on Earth and in the Universe. The extreme thermoacidophile Metallosphaera sedula is a metal mobilizing archaeon, which thrives in hot acid environments (optimal growth at 74°C and pH 2.0) and utilizes energy from the oxidation of reduced metal inorganic sources. These characteristics of M. sedula make it an ideal organism to further our knowledge of the biogeochemical processes of possible life on extraterrestrial planetary bodies. Exploring the viability and metal extraction capacity of M. sedula living on and interacting with synthetic extraterrestrial minerals, we show that M. sedula utilizes metals trapped in the Martian regolith simulants (JSC Mars 1A; P-MRS; S-MRS; MRS07/52) as the sole energy sources. The obtained set of microbiological and mineralogical data suggests that M. sedula actively colonizes synthetic Martian regolith materials and releases free soluble metals. The surface of bioprocessed Martian regolith simulants is analyzed for specific mineralogical fingerprints left upon M. sedula growth. The obtained results provide insights of biomining of extraterrestrial material as well as of the detection of biosignatures implementing in life search missions.

Partitioning sediment flux by provenance and tracing erosion patterns in Taiwan

AbstractWe critically evaluate the potential and limitations of an alternative way to calculate erosion rates based on petrographic and mineralogical fingerprints of fluvial sediments coupled with gauged sediment fluxes. Our approach allows us to apportion sediment loads to different lithological units, and consequently to discriminate erosion rates in different tectonic domains within each catchment. Our provenance data on modern Taiwanese sands indicate focused erosion in the Backbone Range and Tananao Complex of the retrowedge. Lower rates are inferred for the northern part of the island characterized by tectonic extension and for the western foothills in the prowedge. The principal factor of uncertainty affecting our estimates is the inevitably inaccurate evaluation of total sediment load, because only the suspended flux was measured. Another is the assumption that suspended load and bed load are derived from the same sources in fixed proportions. Additional errors are caused by the insufficiently precise definition of lithologically similar compositional end‐members and by the temporal variability of sediment composition at the outlet of each catchment related to the spatial variability of erosional processes and triggering agents such as earthquakes, typhoons, and landslides. To evaluate the robustness of our findings, we applied a morphometric technique based on the stream‐power model. The results obtained are broadly consistent, with local discrepancies ascribed to poorly constrained assumptions and choices of scaling parameters. Our local erosion estimates are consistent with GPS uplift rates measured on a decadal timescale and generally higher than basin‐wide results inferred from cosmogenic‐nuclide and thermochronology data.

Modelling the provenance of detritus flushed through the Strait of Bosphorus, Turkey, during early Holocene outflow from the Black Sea to the world ocean

Source-to-sink tracing of very fine sand supplied to a controversial lower Holocene deltaic lobe in the northeastern Marmara Sea was undertaken using SEM backscatter mapping and quantitative ‘mineral liberation analysis’ of very fine sand fractions. Forty-two samples from the Kurbağalıdere, Göksu, Golden Horn and Riva watersheds, and from Oligo-Miocene outcrops along the southwestern Black Sea coast, show that each of these potential sources has a distinct mineralogical fingerprint. Comparison with 11 samples from the lower Holocene delta and 19 samples from the overlying mud drape show that no single source can account for the mineral proportions in the sand fractions of these depositional sinks, but a mixed provenance provides good matches. For the deltaic lobe, quantitative mixing based on 250,000 Monte Carlo simulations suggests ~50% contribution from Oligo-Miocene successions of the southwestern Black Sea coast and inner shelf, ~20% contribution from the Göksu stream, and minor contributions from other sources including the Kurbağalıdere stream. This balance of source contributions continued to supply the Holocene mud drape until ~6calka, after which local sources became more important. It is hypothesized that unconsolidated sediment from a number of watersheds was parked along the coast of the Neoeuxine Lake and in the paleo-Bosphorus valley during the MIS 2 lowstand. A rising Neoeuxine Lake, possibly swollen by glacial outburst floods from the Altay region of Central Asia, flushed ~0.5km3 of this sediment through the Strait of Bosphorus to the deltaic lobe and permitted it to rapidly advance into the Marmara Sea, which at that time was rising ~1m each 100yr. Provenance of the lower portion of the Holocene mud drape is consistent with continued Black Sea outflow throughout the deposition of sapropel M1 in the Marmara Sea.

Geochemical and mineralogical fingerprints to distinguish the exploited ferruginous mineralisations of Grotta della Monaca (Calabria, Italy)

This study examines the geochemical and mineralogical variations in the ferruginous mineralisations that crop out within Grotta della Monaca, which is considered to be the most striking and best known example of a prehistoric iron mine-cave from the southern Apennines (Calabria, Italy). Previous archaeological research identified three local and distinct ancient exploitation phases of these ferruginous mineralisations: (1) an Upper Palaeolithic phase; (2) a Late Neolithic phase; and (3) a post-Medieval phase. These materials, which have various forms of complex mineralogical admixtures and range in colour from yellow-orange to red and darker brown shades, mainly consist of iron oxides/hydroxides (essentially goethite and lepidocrocite), which are often mixed with subordinate and variable amounts of other matrix components (carbonates, sulphates, arsenates, silicates and organic matter). Such ferruginous mineralisations generally correspond to geochemically heterogeneous massive dyke/vein/mammillary/stratiform facies that are exposed within the local caves along open fractures and inclined bedding planes and that partially cover cave wall niches/notches/pockets and ceiling cupolas/holes. Selected samples/sub-samples are analysed through a multi-technique approach with a handheld portable X-ray Fluorescence, X-ray Diffraction, micro-Raman and Fourier Transform Infrared spectroscope (both conventional and attenuated total reflection), which is combined with subsequent multivariate statistical analysis of the elemental concentration data. The geochemical and mineralogical results are used to individualise similar compositional clusters. As expected, the identified groups, each of which has very specific geochemical-mineralogical “fingerprints” and spatial distributions, enable us to identify the sampled ferruginous mineralisations. These specific mineral resources can be compared to similar raw materials that are found in other neighbouring archaeological sites, with obvious implications toward understanding local exploitation strategies through time and the exchanges and kinship networks of these materials.

Advances in elemental imaging of rocks using the AGLAE external microbeam

Rocks are widely represented in cultural heritage materials. They constitute the major part of archaeological artefacts like stone carvings, tools and weapons, and are present in art works in various forms, such as precious stone inlays or paint pigments. The study of such geomaterials, which are usually constituted of a complex aggregate of mineral phases, aims at determining their exact nature, their provenance and at understanding their possible alteration. Since minerals are often composed of light elements, IBA techniques such as PIXE and PIGE, thanks to their ability to measure with high sensitivity elements down to lithium, should be well adapted to their analysis. However, the bulk composition classically obtained using macro-IBA on pelletized samples or using a broad beam hides the multi-phased nature of the rocks and considerably blurs the searched chemical fingerprint. In contrast, the small size of a nuclear microprobe allows imaging the chemical composition at a finer scale and, when implemented in air, appears ideally suited to analyse without sampling these often precious items. This paper illustrates chemical micro-imaging of rocks with examples performed with the AGLAE external nuclear microprobe: characterisation of microscopic inclusions in gems and detailed chemical mapping of rocks with special emphasis to lapis lazuli. Lapis lazuli is of particular interest in both archaeology and art history: after being employed in Asia since the 7th millennium BC to make carvings and beads, it was used in Medieval Europe as a precious blue painting pigment known as ultramarine. The chemical imaging of major and trace elements in lapis lazuli using external μ-PIXE has permitted to identify its mineral phases, to assign their trace elements and to evidence undetected elements. In combination with μ-XRD and μ-Raman spectrometry, this approach provides a clear mineralogical fingerprint useful to determine rock provenance and to authenticate artefacts of unknown origin. These encouraging results call for the generalization of this non-destructive approach to the study of other heterogeneous materials in art and archaeology.

Re-advance of the Fennoscandian Ice Sheet during Heinrich Event 1

Five sediment cores, bathymetric and 2D seismic reflection data from Vestfjorden, northern Norway, were studied in order to constrain the timing and extent of a major ice stream draining the northwestern Fennoscandian Ice Sheet during the last deglaciation (15–10 14C ka B.P.). The bathymetric and seismic data indicate that Vestfjorden/Trænadjupet was covered by grounded ice reaching the shelf break during the Last Glacial Maximum (LGM). After the LGM break-up and recession towards outer inner Vestfjorden at ∼ 13.6 14C ka B.P., the ice re-advanced towards the outer part of Vestfjorden prior to 13.1 14C ka B.P. This is inferred from glaciomarine sediments overlain by diamicton at the base of the sediment cores interpreted as basal tills and associated contemporaneous build-up of grounding zone wedges in the central Vestfjorden. This sequence of events is coherent with the late Weichselian ice sheet dynamics both along the western Norwegian continental shelf and in the Barents Sea, possibly indicating a direct response to meltwater injection and accompanied cooling during disruption of the thermohaline circulation associated with Heinrich Event 1. Enhanced supply of suspension load resulted in deposition of laminated sediments at ∼ 13 14C ka B.P. reflecting the retreat of the ice stream towards the inner fjord in response to global climate amelioration and increased Atlantic water inflow. Two additional ice re-advances towards the Norwegian coastline are inferred from distinct input of ice-rafted debris (IRD) with a typical mineralogical fingerprint derived from Neoproterozoic–Early Silurian calcite and dolomite marbles in the ice sheet catchment area. Thus, the re-advances may be concurrent with the Older Dryas (∼ 12.2 14C ka B.P., Skarpnes) and Younger Dryas (∼ 10.7 14C ka B.P., Tromsø Lyngen) cooling events.

Mechanisms and Sources of Mantle Metasomatism: Major and Trace Element Compositions of Peridotite Xenoliths from Spitsbergen in the Context of Numerical Modelling

Mineral and whole-rock chemical data for peridotite xenoliths in basaltic lavas on Spitsbergen are examined to reassess mechanisms of melt-fluid interaction with peridotites and their relative role versus melt composition in mantle metasomatism. The enrichment patterns in the xenoliths on primitive mantle-normalized diagrams range from Th-La-Ce 'inflections' in weakly metasomatized samples (normally without amphibole) to a continuous increase in abundances from Ho to Ce typical for amphibole-bearing xenoliths. Numerical modelling of interaction between depleted peridotites and enriched melts indicates that these patterns do not result from simple mixing of the two end-members but can be explained by chromatographic fractionation during reactive porous melt flow, which produces a variety of enrichment patterns in a single event. Many metasomatized xenoliths have negative high field strength element and Pb anomalies and Sr spikes relative to rare earth elements of similar compatibility, and highly fractionated Nb/Ta and Zr/Hf. Although amphibole precipitation can produce Nb-Ta anomalies, some of these features cannot be attributed to percolation-related fractionation alone and have to be a signature of the initial melt (possibly carbonate rich). In general, chemical and mineralogical fingerprints of a metasomatic medium are strongest near its source (e.g. a vein) whereas element patterns farther in the metasomatic 'column' are increasingly controlled by fractionation mechanisms.

Microbiologically influenced corrosion of underground pipelines under the disbonded coatings

The microbiologically influenced corrosion (MIC) of underground pipeline was identified. Corrosion was typically found under the disbonded area of girth welds coating where cathodic protection (CP) current could not penetrate. Sulfate reducing bacteria (SRB) and fermentative acid producing bacteria (APB) were confirmed as the microbes involved in the corrosion process. This corrosion occurred despite the fact that the CP level was well below the criteria of -850 mV (Cu/CuS04). Detailed field surveys and laboratory analysis revealed the presence of high numbers of microbes at these sites, metallurgical and mineralogical fingerprints of MIC. The results indicate that the synergistic effects of disbonding, the ineffective input of CP current under the disbonded coatings, and environments favorable to bacterial growth were the corrosion mechanism.

Mineralogical fingerprints of industrial emissions — an example from Ni mining and smelting on the Kola Peninsula, NW Russia

Fifteen large (>20 kg) snowpack samples, representing the atmospheric deposition of one winter (1995/1996), were collected in the vicinity (1.5–8 km) of the copper–nickel processing plants on the Kola Peninsula, NW Russia. Microscopical (reflected light) and electron microprobe investigations were carried out on polished sections of filter residues (>0.45 μm) of these samples to identify the mineralogical composition of the particulate deposition. The technique allows us to directly distinguish between particles originating from geogenic sources (e.g. windblown rock dust) and additional anthropogenic input from industrial sources. Furthermore, it was possible to gain information on the metallurgical processes used in the different factories (one roasting plant and two smelters using different technology). Each industry emits a very characteristic spectrum of particulates. The mineralogy of the particulate inpute can thus be directly used to unravel the source of observed heavy metal inputs at any one place even in complex situations with several industries located at close distance.

Detecting compositional, spatial, and temporal attributes of glaucony: a tool for provenance research

A reliable interpretation of glaucony-bearing units requires the characterization of compositional, spatial, and temporal attributes of glaucony. The criteria that can readily determine the differentiation of the various types of glaucony (autochthonous, parautochthonous or allochthonous intrasequential, and detrital or allochthonous extrasequential) are discussed in detail.Autochthonous vs allochthonous glaucony may be often detected on the basis of detailed sedimentological investigations, including facies interpretation of glaucony-bearing deposits and careful examination of spatial distribution of glaucony. Textural and morphological features, although generally not diagnostic on their own, provide a significant contribution to glaucony interpretation.The distinction between parautochthonous and detrital glaucony can be sometimes performed by radiometric dating; more commonly, it requires that compositional attributes of glaucony be matched against those of putative sources. Glauconies from distinct parent rocks generally have different maturity and carry unique geochemical and mineralogical fingerprints that may contribute definitive data for provenance research.Previous work on glaucony and examples from units formed in tectonically stable areas (Cretaceous/Eocene deposits of Paris Basin and Hampshire Basin) and active tectonic basin settings (Miocene strata of southern Alps and northern Apennines) provide the opportunity to discuss the validity of the proposed criteria across different structural domains and emphasize the need for an integrated approach to the study of glaucony.