Mineralogy of the pollutant products formed in the Masca exploration area (Lower Iara Valley Basin, Cluj County, Romania)

In the present study the mineralogy of a tailing dam situated in the Maşca mining area is discussed. Our aim was to point out the physicochemical processes, which occur under the action of the exogenous factors. The studied samples were collected from different levels of the dam wall, from the Maşca mine and Iara river waters. The applied analytical methods are: transmission polarized microscopy, transmission electron microscopy, X-ray diffractometry, and atomic absorption spectrometry. The physicochemical parameters have been measured in situ and in the laboratory. The minerals present in the tailings are represented by: garnets (andradite-grossular and almandine series), diopside, hedenbergite, actinolite, tremolite, epidote, zoisite, biotite, phlogopite, serpentine minerals, chlorite, tourmaline, quartz, feldspar, anatase, apatite and opaque minerals (pyrrhotite, pyrite, magnetite and hematite). The carbonate minerals belonging to the mining waste are represented mostly by dolomite and subordinately by calcite. The identified neoformation minerals formed as a result of the action of the exogenous factors are the following: illite, illite/smectite, nontronite, palygorskite, chlorite-vermiculite, gypsum, epsomite, hexahydrite, wattevillite, ferrohexahydrite, hallotrichite, bilinite(?), goethite and amorphous iron hydroxide. The chemical analyses undertaken on the water samples show high values of the soluble salts (Na+, K+, Ca2+, Mg2+, and SO42-) and heavy metals (Cu2+, Pb+, Fe2+, Fe3+, and Zn2+) contents, exceeding international and national guidelines. Although the pH of the streams originating from the mine area vary between neutral to slightly alkaline, pollution occurs and significantly impacts the mineralized area as well as the neighboring areas

Late Quaternary Palaeoclimate Reconstruction Based on Clay Minerals Assemblage from Preluca Tiganului (Gutai Mountains, Romania)

Several core samples were extracted from the overgrown crater lake of Preluca Tiganului, NW Romania. The overall lithology and the mineral assemblages (mostly clay) described from different levels within these cores, suggest three main periods having humid or dry conditions. Based on these findings, palaeoclimate conditions can be reconstructed the over the time period spanning 15,000 to 13,500 cal. years BP

Date noi privind compozitia mineralogica a siltului lutitic de la Dumbrava, judetul Cluj (New Mineralogical Data on the Clayey Silt from Dumbrava (Cluj County)

New Mineralogical Data on the Clayey Silt from Dumbrava (Cluj County). New mineralogical data on the lutitic silt occurrence from the Dumbrava (Cluj County, Romania), based on TEM and X-ray diffraction studies, are presented in the paper. Mainly kaolinite, and subordinately illite and illite/montmorillonite represent the mineralogical compounds of the clayey fraction of the rock. The lutitic silt represents a local facies, sedimented in subaquatic environments (a small lake or pool) after a short-distance transport from the sources. The source for the brown clays was probably a paleosoil formed nearby magmatic rocks. The source for the light coloured clays (creamy gray) was the alterated zone of metamorphic rocks

New remarks on the lithology and biostratigraphy of the Cretaceous deposits from Istria Depression (Black Sea shelf)

The lithological and micropaleontological study of samples collected from several boreholes drilled in the Mesozoic deposits of Istria Depression (Black See shelf) allowed the characterization of intersected Cretaceous successions. Berriasian - Valanginian deposits are terrigenous, represented mainly by sandstones in the lower parts, and clays above. It is impossible to document the presence of Hauterivian-Aptian deposits in the succession. The Albian deposits are still terrigenous (predominantly clays, sometimes with sponge spicules). The Cenomanian transgressive deposits are coarser, and contain Conicorbitolina conica (d’Archiac), Rotalipora cushmani (Morrow) and Hedbergella-Praeglobotruncana sp. The following Turonian?-Campanian-Maastrictian deposits are micritic limestones with planctonic foraminifera in specific successions: Globotruncana cf. elevata (Brotzen), Globotruncana bulloides (Vogler), Globotruncana arca (Cushman), Globotruncana contusa (Cushman), Gansserina sp. For these specific successions the assemblage indicates a Campanian-Maastrictian age. The age of the most underlying deposits could be estimated only by comparisons with published data (Băncilă et al., 1997)