Chert raw materials and artefacts from NE Bulgaria: A combined petrographic and LA-ICP-MS study

In the present study two analytical methods are applied to characterize chert artefacts and raw materials from northeastern Bulgaria (Ludogorie region): petrographic observation and laser ablation inductively coupled plasma mass spectrometry). Archaeological samples from 12 Chalcolithic sites from Bulgaria are analyzed as well as raw material from 6 outcrops in northeastern Bulgaria are identified and documented during a survey in 2012 when many raw material samples were collected. The chert raw material mostly occurs in various Quaternary secondary deposits, originating from destruction and disintegration of the Lower Cretaceous (Aptian) limestones in the area. The paper is aimed at tracing the provenance of the artefacts based on their petrographic characteristics and geochemical composition. The archaeological evidence shows a wide distribution of the Ludogorie chert throughout the country.On the basis of micropetrographic observations, Gurova and Nachev (2008) described two main chert types (Ravno and Kriva Reka). Our petrographic study confirmed the previous results and an additional chert type was distinguished, originating from primary and secondary deposits (quarries in Koprivetz and Krasen villages) and is represented by silicified limestones (bioclastic-peloidal packstones or grainstones). It is noteworthy that the first two types of chert were largely used for prehistoric artefact manufacturing while the last one is not attested among studied assemblages at all

Sulfide trace element signatures and S- and Pb-isotope geochemistry of porphyry copper and epithermal gold-base metal mineralization in the Elatsite–Chelopech ore field (Bulgaria)

The Elatsite–Chelopech ore field in the northern part of the Panagyurishte district in Central Bulgaria comprises numerous spatially associated porphyry copper and epithermal gold deposits and prospects. In addition to the mineralization and alteration features, trace elements, lead and sulfur isotope signatures of sulfide minerals from porphyry copper, base metal and gold-base metal deposits/prospects have been studied. LA-ICP-MS analyses of pyrite, arsenopyrite and sulfosalt minerals validate them as major carriers for Au, Ag, Sb, Se and Co. Pyrite from the three types of mineralization has specific geochemical characteristics. Pyrite from the porphyry copper deposits/prospects has generally lower total trace element content compared to pyrite from the epithermal prospects, except for Se, Co and Ni. Pyrite from the base metal and gold-base metal veins is enriched in As, Au, Ag, Sb and Pb. In pyrite from the base metal deposits, Co and Ni have contents comparable to the pyrite from the porphyry copper deposits, while pyrite from the gold-base metal veins shows lower Co and Ni. Arsenopyrite from these deposits shows similar features. Similarly, sphalerite from the gold-base metal veins also has lower Co content compared to sphalerite from the base metal veins but higher In and Cu contents. In addition to the close spatial relationships between the Elatsite and Gorna Kamenitsa porphyry Cu deposits and Negarstitsa-West and Dolna Kamenitsa base metal prospects, as well as similarities in the mineralization and alteration styles, the lead isotopic (206Pb/204Pb = 18.61–18.68, 207Pb/204Pb = 15.64–15.65 for porphyry and 206Pb/204Pb = 18.55–18.67, 207Pb/204Pb = 15.64–15.68 for base metal) and sulfur isotopic (δ34S values of −3 to +1‰ for porphyry and δ34S values of −1.7 to +3.5‰ for base metal) signatures of sulfides support the idea of a genetic link between these two types of deposits. The porphyry and base-metal mineralization result from a common major ore-forming event during the Late Cretaceous, corresponding to deep/higher-temperature and shallower/distal/lower-temperature environments, respectively. In particular, more radiogenic lead (206Pb/204Pb = 18.41–18.47, 207Pb/204Pb = 15.67–15.76) and slightly different sulfur isotopic compositions (δ34S values of +3.5 to +10.6‰) of sulfides from the distal gold-base metal veins of Kordunsko Dere, Svishti Plaz and Shipkite might be a consequence of the interaction of the ore-forming fluids with an external older crustal and isotopically positive S source. Alternatively, a different fluid source/event for the formation of these gold-base metal veins may be suggested

Uspostavljanje popisa morskih invazivnih vrsta u ESENIAS području: sadašnja situacija i buduća očekivanja

In this study we present a list of invasive/potential invasive alien species in the East and South European Network for Invasive Alien Species (ESENIAS) countries with marine borders. The species were classified according to the existing literature and experts’ judgment, as established, casual, invasive and expected. Finally, factsheets were compiled for ten species of high importance based on their expanding/invading character. Of the 160 species comprising the list, 149 were already present in the ESENIAS countries, while eleven were invasive species either present in the Mediterranean or in other European Seas, likely to be recorded in the ESENIAS countries. The majority of the species were of Red Sea/IndoPacific origin (97 species; 60.6%). Italy, Turkey and Greece were the countries with the highest representation of species (159, 152 and 139 species respectively), due to their extended coastline and the number of scholars working on marine invasive species. The highest number of established species was recorded in Turkey (116 species), whereas in Italy and Greece the most numerous species were the “expected” ones (85 and 48 species, respectively). The eastern Adriatic Sea countries (i.e. Albania, Croatia, Montenegro and Slovenia) had generally low numbers of species in this list, many of which are still “expected” to arrive from the neighbouring countries of Greece and Italy. Finally, the most frequently potential pathway was transfer stowaways (ship ballast water: 41 cases; ship hull fouling: 55), whereas unaided spread of Lessepsian immigrants followed (95 cases). This list is intended to serve as an early warning system that through horizon scanning process would assist ESENIAS countries to prioritise invasive alien species, their pathways and the areas of higher likelihood to appear, in order to take management measures.U ovom radu predstavljamo popis invazivnih i potencijalno invazivnih vrsta na istoku i jugu Europske mreže za invazivne vrste (ESENIAS) u zemljama s morskim granicama. Vrste su klasificirane prema postojećoj literaturi i procjeni stručnjaka, pa su tako utvrđene grupe povremenih, invazivnih i očekivanih vrsta. Podaci su dati za deset vrsta čija se važnost temelji na njihovom širenju i invazivnom karakteru. Od 160 vrsta koje sadrži popis, 148 je već bilo prisutno u ESENIAS zemljama, dok je 9 invazivnih vrsta bilo prisutno u Sredozemnom ili u drugim europskim morima, a vjerojatno je da će se zabilježiti i u zemljama udruženim u ESENIAS. Većina vrsta je bile iz Crvenog mora / indopacifičkog podrijetla (97 vrsta, 60,6%). Italija, Turska i Grčka su zemlje s najvišom zastupljenošću vrsta (159, 152 i 139), zbog njihove proširene obale i broja znanstvenika koji rade na morskim invazivnim vrstama. Najveći broj utvrđenih vrsta zabilježen je u Turskoj (116 vrsta), dok su u Italiji i Grčkoj najbrojnije vrste bile “očekivane” (85 i 48 vrsta, respektivno). Istočne zemlje Jadranskog mora (npr. Albanija, Hrvatska, Crna Gora i Slovenija) imale su općenito nizak broj vrsta na ovom popisu, od kojih mnoge još “očekujemo” da pristignu iz susjednih zemalja: Grčke i Italije. Konačno, najčešće su potencijalni putovi bili „transferni putnici“ (balastna voda broda: 41 slučaj, obraštaj brodskog trupa: 55), dok je slijedilo i širenje lesepsijskih migranata (95 slučajeva). Ovaj popis je namijenjen da služi kao sustav ranog upozorenja koji bi kroz proces skeniranja pomogao državama ESENIAS da daju prioritet invazivnim stranim vrstama, njihovim putovima i područjima veće vjerojatnosti pojavljivanja, kako bi se poduzele potrebne mjere upravljanja

Response of the Black Sea Zooplankton to the Marine Heat Wave 2010: Case of the Sevastopol Bay

Global warming is increasing the frequency and severity of the marine heat waves, which poses a serious threat to the marine ecosystem. This study analyzes seasonal and interannual dynamics in the abundance and structure of the mesozooplankton community in Sevastopol Bay based on bi-monthly routine observations over 2003–2014. The focus is on the impact of the summer 2010 marine heat wave (MHW2010) on crustaceans belonging to different ecological groups. As a response to the MHW2010, three warm-water species (O. davisae, A. tonsa and P. avirostris) exhibiting the maximum seasonal density in latter summer showed a sharp increase in the annual abundance and their share in the mesozooplankton community. The increase in the annual abundance in 2010 of the eurythermal species P. parvus and P. polyphemoides exhibiting seasonal peaks in spring and autumn is not related to the MHW2010 but can be explained by a rise of temperature in the first part of the year. O. davisae and A. tonsa showed the most pronounced response among the species to the MHW2010, confirming that non-native species exhibited great flexibility as an adaptive response to environmental changes, especially in the case of climate warming. Among crustaceans observed in this study, O. davisae can be considered as an indicator of the environmental conditions associated with the warming of the Black Sea and the Mediterranean basin as a whole

Flint raw material transfers in the prehistoric Lower Danube Basin: An integrated analytical approach

The paper presents results of a research programme focused on the provenancing of flint raw materials used in the prehistory of the Lower Danube Basin of the Balkans. Field survey encompassed two adjacent regions connected by the Danube River. First, northern Bulgaria where rich flint-bearing Cretaceous deposits are known along with numerous Neolithic sites but with limited pre-Neolithic presence apart from several well-known Middle to Upper Palaeolithic sequences. Second, the Danube Gorges area on the southern, Serbian side of the river, characterized by relatively scarce deposits of flint, but with one of the best preserved concentrations of Mesolithic, transitional and Early Neolithic sites in the wider region of southeastern Europe. Focusing on both of the two selected regions allows one to follow diachronic dynamics in supply and circulation of local and non-local flint raw materials along the examined stretch of the Lower Danube Basin. In order to connect surveyed flint outcrops and different types of raw material used in archaeological contexts, an integrated approach was employed using both petrographic thin sections and LA-ICP-MS trace element chemical finger-printing analyses

The Ilovitsa porphyry Cu-Au deposit: Vein sequence, sulfide deposition and fluid inclusion study

The Ilovitsa porphyry Cu-Au deposit is located 30 km away from the town of Strumitsa, SE FYR Macedonia. It is hosted in a Triassic granite (251.90 ±0.89 Ma, Georgiev et al. 2013).The latter intrudes into the metamorphic rocks of the Vertiscos- Ograzhden Unit of the Serbo-Macedonian massif. Formation of the Ilovitsa deposit is related to the intrusion of multiple Tertiary porphyry intrusions (called the Ilovitsa Stock) and dykes. The Ilovitsa stock that hosts the Cu-Au mineralization is made up by two main intrusions with a similar granodioritic composition dated by ID-TIMS at 30.31 ±0.05 Ma and 30.13±0.03 Ma (Georgiev et al. 2013). The authors have determined that the ages of the dykes are between 28.8 and 29.6 Ma

Genesis of the Erdaohezi Deposit, Inner Mongolia, China: Constraints from LA-ICP-MS Trace Element Geochemistry of Sphalerite

The Erguna block is one of the most important Pb-Zn-Ag metallogenic provinces in East China. In this study, the laser ablation-inductively coupled plasma mass spectrometry ( LA-ICP-MS) and electronic probe have been used to determine the major and trace element concentrations of three generations sphalerites (sph1, sph2 and sph3) from the Erdaohezi Pb-Zn polymetallic deposit, a representative deposit in the Erguna block, in order to reveal the enrichment regulation and occurrence state of elements in sphalerites of the deposit, to explore physico-chemical conditions controlling the mineralization of the deposit, and to provide much more insights for discriminating genesis of the deposit. Our results show that the sphalerite is enriched in Fe, Mn, Cd, and In, but is depleted in Ga, Ni, Ge, Tl, and Se. From the earliest sphalerite generation (sph1) to the youngest sphalerite generation (sph3), the Fe and Mn contents of sphalerites are gradually decreased, whereas the Hg contents of sphalerites are gradually increased. Comparing to other two generations of sphalerite, the sph2 sphalerite contains relatively high concentrations of Cu, Pb, Bi, Sn, and Ag but relatively low contents of In. The time-resolved depth profiles and elemental correlation analyses of sphalerite reveal that elements including Mn, Hg, Cd, In, and Sn are mainly incorporated into the sphalerite lattice in the form of homomorphic substitution, Pb and Cu occurred mostly as mineral micro-inclusions in the sphalerite, but Fe and Ag occurred both as solid solution and mineral micro-inclusions in the sphalerite. The trace element contents and ratios of Zn/ Cd and Ga/ In of sphalerites indicate that sphalerites of the first two generations were formed under a condition of medium-high temperature and reduced environment, whereas the sphalerite of latest generation was formed under a condition of relatively low reduced environment at relatively low temperature. On the basis of field observations, previous studies, and characteristics of trace element of sphalerites using the in situ microanalysis, we have concluded that the Erdaohezi Pb-Zn polymetallic deposit belongs to an epithermal Pb-Zn-Ag polymetallic deposit related to late-stage subvolcanic rocks or concealed intrusions

A Fluid Inclusion and Critical/Rare Metal Study of Epithermal Quartz-Stibnite Veins Associated with the Gerakario Porphyry Deposit, Northern Greece

The Gerakario Cu-Au porphyry deposit in the Kilkis ore district, northern Greece, contains epithermal quartz-stibnite veins on the eastern side of the deposit, which crosscut a two-mica gneiss. Metallic mineralization in these veins consists of stibnite + berthierite + native antimony + pyrite + arsenopyrite, and minor marcasite, pyrrhotite, chalcopyrite, löllingite, and native gold. Bulk geochemical analyses of the ore reveal an enrichment in critical and rare metals, including Ag, Au, Bi, Ce, Co, Ga, La, and Sb. Analysis of stibnite with LA-ICP-MS showed an enrichment in base metals (As, Cu, Pb), as well as weak to moderate contents of critical and rare metals (Ag, Bi, Ce, La, Re, Sm, Th, Ti, Tl). A statistical analysis of the trace elements show a positive correlation for the elemental pairs Ce-La, Ce-Sb, and La-Sb, and a negative correlation for the pair Bi-Sb. Fluid inclusions in the A-type veins of the porphyry-style mineralization show the presence of fluid boiling, resulting in a highly saline aqueous fluid phase (35.7 to 45.6 wt.% NaCl equiv.) and a moderately saline gas phase (14 to 22 wt.% NaCl equiv.) in the system H2O-NaCl-KCl at temperatures varying between 380° and 460 °C and pressures from 100 to 580 bar. Mixing of the moderate saline fluid with meteoric water produced less saline fluids (8 to 10 wt.% NaCl equiv.), which are associated with the epithermal quartz-stibnite vein mineralization. This process took place under hydrostatic pressures ranging from 65 to 116 bar at a depth between 600 and 1000 m, and at temperatures mainly from 280° to 320 °C.This article is published as Stergiou, Christos L., Vasilios Melfos, Panagiotis Voudouris, Lambrini Papadopoulou, Paul G. Spry, Irena Peytcheva, Dimitrina Dimitrova, and Elitsa Stefanova. "A Fluid Inclusion and Critical/Rare Metal Study of Epithermal Quartz-Stibnite Veins Associated with the Gerakario Porphyry Deposit, Northern Greece." Applied Sciences 12, no. 2 (2022): 909. doi:10.3390/app12020909. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/)

A Fluid Inclusion and Critical/Rare Metal Study of Epithermal Quartz-Stibnite Veins Associated with the Gerakario Porphyry Deposit, Northern Greece

The Gerakario Cu-Au porphyry deposit in the Kilkis ore district, northern Greece, contains epithermal quartz-stibnite veins on the eastern side of the deposit, which crosscut a two-mica gneiss. Metallic mineralization in these veins consists of stibnite + berthierite + native antimony + pyrite + arsenopyrite, and minor marcasite, pyrrhotite, chalcopyrite, löllingite, and native gold. Bulk geochemical analyses of the ore reveal an enrichment in critical and rare metals, including Ag, Au, Bi, Ce, Co, Ga, La, and Sb. Analysis of stibnite with LA-ICP-MS showed an enrichment in base metals (As, Cu, Pb), as well as weak to moderate contents of critical and rare metals (Ag, Bi, Ce, La, Re, Sm, Th, Ti, Tl). A statistical analysis of the trace elements show a positive correlation for the elemental pairs Ce-La, Ce-Sb, and La-Sb, and a negative correlation for the pair Bi-Sb. Fluid inclusions in the A-type veins of the porphyry-style mineralization show the presence of fluid boiling, resulting in a highly saline aqueous fluid phase (35.7 to 45.6 wt.% NaCl equiv.) and a moderately saline gas phase (14 to 22 wt.% NaCl equiv.) in the system H2O-NaCl-KCl at temperatures varying between 380° and 460 °C and pressures from 100 to 580 bar. Mixing of the moderate saline fluid with meteoric water produced less saline fluids (8 to 10 wt.% NaCl equiv.), which are associated with the epithermal quartz-stibnite vein mineralization. This process took place under hydrostatic pressures ranging from 65 to 116 bar at a depth between 600 and 1000 m, and at temperatures mainly from 280° to 320 °C