Geologica Macedonica

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Goran Tasev — Wed, 27 Nov 2024 12:14:21 +0000

Goran Tasev — Wed, 27 Nov 2024 12:15:30 +0000

Impressum

Goran Tasev — Wed, 27 Nov 2024 12:16:03 +0000

INSTRUCTIONS TO AUTHORS

Goran Tasev — Wed, 27 Nov 2024 12:16:26 +0000

NEW OPTIMIZED LIQUID-LIQUID EXTRACTION METHOD FOR THE REMOVAL OF THALLIUM AS A MATRIX ELEMENT IN MINERALS

Wed, 27 Nov 2024 12:06:09 +0000

When screening the content of trace elements in minerals or other inorganic compounds, the detection limit is raised and determination by spectroscopic techniques is often questionable or even impossible due to their interference with the matrix elements of the minerals. Thus, some valuable trace elements may remain undetected, which lowers the estimation for potential economic exploration of the geological deposit or site. Therefore, the main objective of this research was to find a suitable, cost-effective, reliable and rapid method for the selective and consecutive elimination of thallium and arsenic in the analysis of As-Tl minerals and to lower the detection limit for the determination of the trace elements present. The method was based on the separate optimization of the molarity of HCl and the volume of organic solvents including diisopropyl ether, diethyl ether, n-amyl acetate and isoamyl acetate. The optimized HCl concentration enabled the extraction of thallium (as chloride complex) and its migration into the organic top layer. The optimization of the method was performed with
thallium(I) nitrate and then realgar (As4S4) was added to simulate the composition matrix for lorandite (TlAsS2), as the latter mineral is very rare and valuable to be used for screening. In addition, a multi-element standard solution (Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mo, Ni, Pb, Sr, Tl, V, Zn) was used to simulate the trace elements that may be present. Once all conditions were optimized, a two-step liquid-liquid extraction with n-amyl acetate (to eliminate Tl) and toluene with KI (to eliminate As) was performed for the dissolved lorandite. All elements were determined by inductively coupled plasma - atomic emission spectrometry and the results were correlated with those obtained by k0-instrumental neutron activation analysis from the same, previously powdered, lorandite specimen.

AGE OF THE PEGMATITES IN THE PELAGONIAN METAMORPHIC COMPLEX

Ivan Boev, Tena Šijakova Ivanova, Sonja Lepitkova — Wed, 27 Nov 2024 12:08:13 +0000

The Pelagonian metamorphic complex, or tectono-stratigraphic complex, extends approximately 420 km in length and 60 km in width in a NNW-SSE orientation, forming part of the central Hellenides. The occurrence of pegmatites within the Pelagonian metamorphic complex is quite common. They appear within the metamorphic complex of the gneisses and in direct contact with the granitic intrusive bodies. Mainly these pegmatite bodies are made of quartz, feldspars, micas (bioite, muscovite, paragonite, vermuiculite) as well as are the occurrence of rare minerals such as tourmalines, epidotes, apatites, garnets and zircons. The paper presents the new information related to the age of two pegmatitic bodies by the U/Pb dating and the K/Ar dating: Alinci and Čanište. The obtained age is Cretaceous.

ANALYSIS OF MICROTREMORS BY MEASURING AND PROCESSING OF AMBIENT VIBRATIONS TESTS

Mirjana Kocaleva Vitanova, Vlado Gičev — Wed, 27 Nov 2024 12:09:56 +0000

Microtremors, small-scale ground vibrations typically with amplitudes ranging from micrometers to millimeters, have emerged as a valuable tool for studying various aspects of Earth's subsurface properties and dynamics. This paper provides an overview of the methodologies employed in the detection, analysis, and interpretation of microtremors for a two-story reinforced concrete building located in Berovo.

MORPHOLOGICAL AND CHEMICAL CHARACTERISTICS OF GRAINS OF PLACER GOLD FROM THE OTINJA RIVER

Lazar Ǵorgiev, Violeta Stefanova, Goran Tasev — Wed, 27 Nov 2024 12:11:26 +0000

In the Serbo-Macedonian metallogenic province in the Republic of North Macedonia, numerous occurrences of Au have been found in alluvial sediments. Placer gold originates from known genetic types of Cu-Au porphyry deposits (Bučim and Borov Dol) and epithermal Au deposits (Plavica and Allchar). However, in the Otinja river, the primary source of Au still remains unclear. Twenty-three Au grains collected from the river of Otinja alluvion were primarily analyzed on a scanning electron microscope (SEM) to investigate their morphological and chemical characteristics. The gold aggregates that were found range in size from about 120 μm to 2 mm, they have mostly sub rounded to rounded shapes, rarely irregular shapes, with microtextures indicating a source at a distance of several km. Chemical composition tests show mainly Au-Ag mixtures, with Au contents ranging from 94.45 to 100%. By chemism, Au grains belong to the group of very high grade gold with high purity (951 to 1000). In general, impurity contents are very low. In order of representation, the following are most present: Ag (0.02–4.89%), Fe (0.02–4,74%), Cu (0.02 0.54%), Te (0.09–0.55%), and Se (0.29%).

NATURAL TRACERS AS A TOOL FOR UNDERSTANDING THE FUNCTIONING OF THE KARST SYSTEM AND ITS VULNERABILITY - A CASE STUDY OF THE MANASTIREC SPRING

Biljana Gičevski, Vojo Mirčovski, Slavčo Hristovski, Metka Petrič — Wed, 27 Nov 2024 12:13:46 +0000

The Manastirec spring is the only drinking water source that supplies 200 inhabitants of the municipality Goren Manastirec in West-Central Macedonia. Natural tracers were applied in order to characterize the properties of the groundwater flow and transport of contaminants through the karst system and to study the functioning of the spring. Water level, temperature and electrical conductivity of the spring were measured with data logger in hourly intervals during several rain events in 2015 and 2016. Rain events caused rise of water level and decrease of both water temperature and electrical conductivity. Concentrations of calcium, magnesium, sulphate and nitrate present in spring water were analyzed during the end of July 2016, during three rain events. The results showed that sulphate and Ca/Mg ratio increase, whereas nitrate decrease after rain events. All results demonstrate high vulnerability of the Manastirec spring to contamination.