This study deals with the mineralogical and chemical characterization of archaeometallurgical material from the Roman archaeological site of Castra (Ajdovščina, western Slovenia). Samples were initially analysed via optical microscopy and X-ray powder diffraction, with the composition of individual phases then determined using scanning electron microscopy coupled with electron-dispersive spectroscopy, and Raman microspectroscopy. Chemical investigation was carried out by using inductively coupled plasma atomic emission spectroscopy to measure the major element content. The results showedthat the slag originated from iron smithing operations, with calcium-rich olivines, as well as wuestite and leucite, the most abundant phases. The investigated slags were also found to be characterized by significantly high lime levels, which probably promoted the formation of the calcium-rich olivines.
COBISS.SI-ID: 1132894
The purpose of this study was to develop a compatible repair mortar for two lithotypes of Peračica tuff (Slovenia): fine-grained and coarse-grained. Mineralogical-petrographic characterization of tuff was carried out via optical microscopy and X-ray powder diffraction, and the relevant physical-mechanical properties of tuff and repair mortars were determined: capillary water absorption, water absorption at atmospheric pressure, open porosity, compressive strength and resistance to salt crystallization. A repair mortar was prepared by mixing crushed Peračica tuff and quartz sand, with different grain size and mass ratios, and ethyl silicate (KSE 500 STE, Remmers) as a binder. The results showed that with an appropriate combination of crushed tuff, quartz sand and ethyl silicate, a compatible repair mortars can be obtained for both lithotypes.
COBISS.SI-ID: 2080359
The first finding of diamond and moissanite in metasedimentary crustal rocks of Pohorje Mountains (Slovenia) in the Austroalpine ultrahigh-pressure (UHP) metamorphic terrane of the Eastern Alps is reported. Microscopic observations and Raman spectroscopy show that diamond occurs in situ as inclusions in garnet, being heterogeneously distributed. Under the optical microscope, diamondbearing inclusions are of cuboidal to rounded shape and of pinkish, yellow to brownish colour. The Raman spectra of the investigated diamond show a sharp, first order peak of sp3-bonded carbon, in most cases centred between 1332 and 1330 cm-1, with a full width at half maximum between 3 and 5 cm-1. Several spectra show Raman bands typical for disordered graphitic (sp2-bonded) carbon. Detailed observations show that diamond occurs either as a monomineralic, single-crystal inclusion or it is associated with SiC (moissanite), CO2 and CH4 in polyphase inclusions. This rare record of diamond occurring with moissanite as fluid-inclusion daughter minerals implies the crystallization of diamond and moissanite from a supercritical fluid at reducing conditions. Thermodynamic modelling suggests that diamond-bearing gneisses attained P–T conditions of ≥3.5 GPa and 800–850 °C, similar to eclogites and garnet peridotites. We argue that diamond formed when carbonaceous sediment underwent UHP metamorphism at mantle depth exceeding 100 km during continental subduction in the Late Cretaceous (c. 95–92 Ma). The finding of diamond confirms UHP metamorphism in the Pohorje Mountains, the most deeply subducted part of Austroalpine units.
COBISS.SI-ID: 1196382
The Alpine–Dinaric Transition Zone in Slovenia comprises the fold and thrust belt of the Southern Alps (South Karawanken Range, Julian Alps), Slovenian Basin and the Dinarides. The Slovenian Basin located between the Julian and Dinaric carbonate platforms evolved during Middle Triassic time and remained in a deep marine setting till the Late Cretaceous. The thermal history of Carboniferous to Eocene rocks in that area was investigated using vitrinite reflectance (VR) data, apatite fission track analysis and numeric 1D basin modeling. The study shows that maturity patterns are mainly controlled by the thickness of Upper Cretaceous to Eocene flysch deposits, filling the accommodation space. Therefore the thermal overprint reaches a maximum () 4%Rr) in Triassic to Cretaceous sediments of the Slovenian Basin and decreases towards the north and south. Minor sedimentary burial of the Adriatic Carbonate Platform and the Julian Alps results in a lower thermal overprint (( 1.5%Rr). The thickness of flysch sediments was about 5 km in the area of the Sava Folds, but significantly higher in the central part of the Slovenian Basin. Heat flow during maximum burial in Eocene time was in the order of the global average (60 mW/m2). Cooling of Paleozoic and Mesozoic sediments below 110 °C occurred between Late Eocene and Early Oligocene times in different parts of the study area. Nappe stacking due to Early (Dinaric) and Late Cenozoic (Alpine) compressional tectonics did not influence the thermal maturity of the sediments.
COBISS.SI-ID: 1245022
In this study the mineralogical and geochemical characteristics of Lake Dojran surficial (0–5, 5–10, 10–15 cm) sediments were studied in order to determine their suitability for use as potential raw material in balneotherapeutic treatments. X-ray powder diffraction (XRD) and inductively coupled plasma mass spectrometry (ICP-MS) analyses were performed, and thereupon chemical index of alteration (CIA) and enrichment factor (EF) values were calculated. The XRD results revealed close association of sediment mineralogy with the prevailing metamorphic, volcanic and igneous rocks of the region surrounding Lake Dojran. CIA values of around 67% suggest a moderate degree of weathering in the lake catchment area. According to the EF value results, surficial Lake Dojran sediments are little enriched with Co, Cr, Cu, Pb, and Zn, moderately enriched with Au, Ni and Sb, moderately severely enriched with Au, severely enriched with Sb and very severely enriched with As. This elemental enrichment likely originates from various different geogenic (geological background and polymetallic mineralization) and anthropogenic (tourism, traffic, coatings, untreated wastewater discharge and agrochemicals) sources. The abundances of the major elements, trace elements and rare earth elements (REEs) were almost constant, changing very little throughout the surficial (0–5, 5–10, 10–15 cm) sediments. Comparison of sediment trace element concentrations with consensus-based threshold effect concentration (TEC) and probable effect concentration (PEC) values showed that lake biota may be under threat of contamination with As, Cu and Ni. Given the present results, we cannot recommend/confirm the application of Lake Dojran dark mud sediment in balneotherapeutic treatments.
COBISS.SI-ID: 1176158