Sylvina Georgieva

• Dr.
• Professor (Assistant) at Bulgarian Academy of Sciences, Geological Institute

The study is focused on the Smilovene pegmatites, targeting estimation of their rare element potential. These bodies bring rare-metal mineralization with LCT geochemical signature and mineral association of albite, oligoclase, microcline, quartz, muscovite, beryl, garnet, fluorapatite, zircon, columbite, samarskite-(Y), monazite-(Ce), magnetite, an...

Calcic skarns are formed on the pegmatite/marble contact in the region of Dzhendemski Ezera, NW Rila, Bulgaria. The garnet/vesuvianite-dominated association is formed in the marbles of the Malyovitsa Lithotectonic Unit as a result of emplacement of crosscutting pegmatite injections. Large (up to 3 cm) prismatic vesuvianite crystals and their radiat...

The trace elements composition of feldspars, both plagioclase and K-feldspar, from the Ossogovo Mountain region, SW Bulgaria, was studied with the aim to combine characteristic indicative geochemical composition with an assessment of the feldspars’ economic potential as critical raw material. The feldspars reveal higher concentrations of Sr, Pb, Ba...

Selected pegmatite dyke intruded within the gneiss-marble-amphibolite sequence of the Rhodope Metamorphic Complex was studied for its REY+ACT mineralization in attempt to assess the potential of these pegmatites for critical and strategic raw materials. Mineral composition of K-feldspar and albite is complemented by abundant common accessories of z...

The Djurkovo base-metal vein deposit in Laki ore field, is hosted by a heterogeneous gneiss/amphibolite/marble rock sequence of the high-grade metamorphic complex of the Central Rhodopes. Mineralogical and geochemical investigation was conducted on slightly deformed, and hydrothermally altered thin pegmatite dykes intruded in the marbles. The pegma...

The Sedefche Au-Ag deposit is located in the eastern Rhodopes, Bulgaria and is part of the Zvezdel-Pcheloyad ore field. The deposit is of low-sulphidation epithermal type, hosted in Oligocene highly silicificated intermediate volcanic tuffs, which lie above shallow marine sediments of organogenic limestones. The orebody has stratiform shape partly...

The major and trace-element chemistry of two pyrite generations (Py1 and Py2) from the Kandilka epithermal prospect was studied by EDS-scanning electron microscopy and laser ablation ICP-MS techniques. Both generations of pyrite are distinguished by occurrence and chemical properties. Pyrite from the first generation (Py1) is established as trace-e...

Mineralogical and geochemical study was done on weakly deformed, relatively thin pegmatites that intruded the marbles of the Rhodope metamorphic complex in the Djurkovo Pb-Zn deposit, Central Rhodopes. The pegmatites consist mainly of K-feldspar and quartz and contain minor garnet; the pegmatites lack clear zonation except for the preferable crysta...

Large pegmatite body/bodies are outcropping in the “Suhata Reka” quarry, near the town of Rakitovo. Their bulk mineral composition with dominant K-feldspar (40%), plagioclase (30%), quartz (25%) and mica (≤ 5%) is complemented by (REE+Y)-bearing association of primary and secondary accessories. Zircon, monazite, xenotime, scarce apatite and noticea...

Ages of pegmatites from two localities (Rakitovo, Lepenitsa) from the western Rhodope Mts. were acquired by U-Pb geochronology on zircon with LA-ICP-MS. The pegmatites are hosted by the metamorphic rocks of the Chepino lithotectonic unit. The large pegmatite/s accumulation from the “Suhata Reka” quarry (Rakitovo locality) is formed at 68.7±1.3 Ma,...

The current study presents results of crystal chemical studies of epidote samples from two Central Rhodope localities. Based on the obtained crystal chemical information, the nomenclature of the investigated species has been justified within the IMA-recommended nomenclature of epidote-group minerals. A comparative study has also been accomplished,...

The current study presents new mineralogical, geochemical and geochronological data for a pegmatite body hosted in gneisses and marbles from the vicinity of the Strashimir Pb-Zn vein deposit, Madan ore district, South Bulgaria. The mineral composition of the studied pegmatite is represented by oligoclase–andesine (An10.1–33.2) and albite (An0–7.6),...

Deformed pegmatites of varying thickness and position are a significant constituent intruded in the metamorphic complex, hosting the Djurkovo Pb-Zn deposit in Central Rhodopes. The mineral composition of the pegmatites consists of plagioclase, K-feldspar, quartz, and minor micas. The main accessory minerals are allanite, titanite, apatite and zirco...

The current study presents mineralogical and geochemical characteristics of pegmatite bodies from the Govedarnika Pb-Zn deposit, situated in Laki district, South Bulgaria. The studied pegmatites are composed mainly of K-feldspar, plagioclase, quartz and accessories of titanite, apatite, allanite and zircon. Intensive hydrothermal alteration resulte...

In the present research, we have applied a combination of Cold-CL petrography with two in-situ techniques (SEM-EDS and LA-ICP-MS) to study quartz-pyrite-sericite veins with some carbonates from the Elatsite porphyry Cu-Au deposit. Based on Cold-CL images, we found out that these veins are formed during two stages: quartz-pyrite with sericite and la...

The current study presents new geochronological and geochemical data for the Petrovitsa Pb-Zn deposit, Central Rhodopes, South Bulgaria. Based on in-situ U-Pb dating of titanites from pegmatites and skarnified mineralized marbles, it aims to provide new insights into the pegmatite formation and their relation to the hydrothermal system in the regio...

The epidote-group minerals are the major hydrothermal constituent, along with titanite, chlorite, quartz, and carbonates, developed in pegmatite on the contact with marble in the vicinity of Strashimir Pb-Zn vein deposit, Central Rhodopes. The U-Pb age of titanite (39.7±1.3 Ma) fixes the time of the hydrothermal mineralization. Trace element signat...

Chlorites are common constituent of the secondary mineral assemblage formed as alteration products after aluminosilicate host rocks in the Pb-Zn deposits in Madan district. In concordant pegmatite body from the Petrovitsa deposit, they are formed after mica flakes. Such transformation often results in abundant rutile grains. The dominant chlorite c...

The epithermal high-sulphidation Cu-Au Chelopech deposit is characterized by a well-developed and well-traceable hydrothermal footprint manifested in the volcanic host rocks. The economic ore mineralization is embedded in the strong silicification, included among the advanced argillic zone of alteration, smoothly transitioning to quartz-sericite al...

Chelopech high-sulphidation epithermal (Cu-Au) deposit with its well-characterized hydrothermal footprint is a perfect object to test whether the geo-chemical features of alunite could be used as a reliable exploration tool. Trace element geochemistry of alunite mineralization from two locations in a suite of samples with well-preserved advance arg...

This study is focused on the mineral assemblages developed during hydrothermal alteration in the host rocks of the Chelopech deposit and aims to reveal some characteristics of ore-forming fluids. Three well-distinguished and simultaneously formed hydrothermal alteration zones, characterized by specific mineral associations, occur in the area: advan...

Whole rock chemical analyses (XRF and LA-ICP-MS of major, trace and rare-earth elements – REE) were conducted to study the chemical changes of the volcanic rocks with andesitic composition from the Chelopech deposit during the hydrothermal alterations. To observe the features of the process, samples from each degree of alteration (propylitic, seric...

Florencite-(Ce, La, Nd) and crandallite (aluminium phosphate-sulphate group – APS) have been determined in the central parts, or as thin zones in the APS zonal crystalline aggregates from the Chelopech high-sulphidation epithermal deposit. The minerals are documented in the advanced argillic alteration zone down to a depth of 2000 m as proven in tw...

Florencite-(Ce,La,Nd) from the advanced argillic alterations in the Chelopech high-sulphidation epithermal Cu-Au deposit, Bulgaria Флоренсит-(Ce,La,Nd) от интензивно аргилизитовите изменения на високосулфидизираното епитермално Cu-Au находище Челопеч, България

Alunite has been determined in the advanced argillic zone of alteration, as well as along with the Cu-AsS ore mineralization in the Chelopech high-sulphidation epithermal deposit. On the Earth surface, alunite is associated with aluminium phosphate-sulphate (APS) minerals, quartz, dickite, kaolinite, pyrite and anatase. At deeper levels, diaspore,...

Abstract. Various aluminium phosphate-sulphate (APS) minerals have been established in several occurrences of advanced argillic alteration, metasomatic quartz or quartz-muscovite-tourmaline zones and supergene oxidation zones of epithermal deposits in the Srednogorie tectonic zone and the Rhodopes. APS minerals occur as individual pseudocubic cryst...

Voluminous areas of advanced argillic alteration (AAA) constitute major exploration targets for surficial Cu–Au epithermal and potentially underlying porphyry-type deposits. In Bulgaria, more than 30 alunite occurrences are recognised, few of them being associated with a mineralised system. A mineralogical study combined with a stable isotopic (O,...