Geochemical background - an environmental perspective

This article presents the concept of geochemical background from an environmental perspective. The idea of establishing the typical concentrations of elements in various environmental compartments, proposed by exploratory geochemists almost 50 years ago was important for the detection of anomalous element concentrations, thus providing a basic tool in the search for new mineral deposits. At present, the knowledge of the geochemical background of hazardous elements is essential for: defining pollution, identifying the source of contamination, and for establishing reliable environmental quality criteria for soils, sediments and surface waters. The article presents geochemical methods of evaluation of anthropogenic influence on the environment and discusses the problem of defining and understanding the term “geochemical background” and related terms in environmental sciences. It also briefly presents methods of geochemical background evaluation based on the results of environmental sample analyses. It stresses the role of geochemical background in our understanding of environmental pollution and pollution prevention

Xenotime from the Podwiśniówka mine pit, Holy Cross Mountains (South-Central Poland)

This report presents the results of petrographical and mineralogical (optical microscopy, SEM/EDS) study of xenotime derived from the Upper (Middle?) Cambrian rocks (Wiśniówka Sandstone Fm.) of the abandoned Podwiśniówka mine pit. This is the first work on this mineral from the Holy Cross Mts. The authigenic xenotime occurs primarily as overgrowths around/on zircon in siliciclastic rocks. Moreover, this mineral is characterized by the large size of the overgrowths reaching 50 μm long and 20 μm wide. The presence of pyritecoated zircon/xenotime aggregates indicates that the xenotime formed prior to hydrothermal quartz-pyrite mineralization. The apparent lack of xenotime and vein pyrite in the tuff-bearing series, compared to the other two series displaying hydrothermal signature (pyrite, hematite, nacrite, jarosite), as well as considerable variations of the xenotime overgrowths in size and morphology, and their dominant irregular patchy-zonal microtexture may provide evidence for direct precipitation of this mineral from hydrothermal fluids

Rare earth elements in acid mine drainage waters : an outline of the issues

This paper presents the brief characteristics of rare earth elements (REE) and their occurrence in acid mine drainage (AMD) waters. The special emphasis is laid on REE classification, computation of shale-normalized coefficients and interpretation of REE anomalies. This paper also outlines the REE behavior in the environment, geochemical interactions and their potential application for assessing an impact of AMD on the environment

The 1st Conference on Contemporary Problems of Geochemistry

This issue of “Mineralogy” includes selected papers based on some oral and poster presentations of the 1st Geochemical Conference on “Contemporary Problems of Geochemistry” organized by the Geochemical Group of the Mineralogical Society of Poland and Jan Kochanowski University in Kielce. The conference was held at the Institute of Chemistry of Jan Kochanowski University in Kielce on 27–30 September 2010

REE-bearing minerals in sediment-hosted stratiform pyrite mineralization zones of the Wiśniówka area (Holy Cross Mts., Poland)

There are two arsenical pyrite (As-FeS2mineralization zones cropping out in the Podwiśniówka and Wiśniówka Duża quarries where quartzites and quartzitic sandstones have been extracted for over a century. A large amount of pyrite in the Wiśniówka siliciclastics is unusual in the hard rock mining throughout the world. The pyritiferous beds contain a variety of REE-bearing minerals, including a crandallite series of aluminum-phosphate-sulfate (APS) minerals, e.g., predominant goyazite SrHAl3[(PO4)2(OH)6] with subordinate gorceixite BaHAl3[(PO4)2(OH)6] and very occasional crandallite CaHAl3[(PO4)2(OH)6]. By contrast, the other REE-phosphate minerals, e.g., xenotime YPO4, bur particularly monazite CePO4 occur in a lesser amount. Goyazite prevails somewhat in the Podwiśniówka beds whereas xenotime in the Wiśniówka Duża beds. Of the other REE-bearing minerals, bastnäsite REECO3(F,OH), florencite (REE)Al3(PO4)2(OH)6 and synchysite CaCe[CO3]2F occur in trace amounts. Interestingly, the quite common phosphate minerals, i.e., wavellite (Al.3[(OH,F)3|(PO4)2]×5H2O and variscite Al[PO4]×2H2O) are depleted in REEs with only Ce attaining 0.09 wt.% as documented by an electron-probe microanalysis. In contrast to quartzites/quartzitic sandstones, carbonaceous clayey-silty shales and bentonites/tuffites are distinctly enriched in REE-bearing minerals. This diversity is also mirrored in the mean total REE concentrations varying from 204 to 314 mg/kg, in clayey-silty shales and bentonites, attaining 457 mg/kg in some Podwiśniówka shale beds. Results of this and the previous petrographic, mineralogical and geochemical studies have indicated that REE-bearing minerals formed generally along with As-rich pyrite, nacrite/dickite and probably TiO2 polymorphs as a result of multiphase hydrothermal vent activity that took place in the Wiśniówka Late Cambrian sedimentary basin. This evidence is also backed up by the values of LREENASC/HREENASC (1.44–1.75) and Eu/EuNASC (1.24–1.30) coefficients in the clayey-silty shales. This positive Eu anomaly (31.20) points to the formation of REE-bearing minerals in a reducing environment