The distribution of major and trace elements in hydrothermal alteration zones (propylitic, argill... more The distribution of major and trace elements in hydrothermal alteration zones (propylitic, argillic, sericitic and advanced argillic) from the Asarel porphyry copper deposit is studied. Strontium was found to demonstrate the most characteristic behaviour among all studied elements – it is depleted from propylitic, argillic and sericitic rocks and concentrates in advanced argillic rocks where it is included in alunite and APS minerals. Manganese, Co, Ni, Zn, Cs, Y, MREE and HREE are strongly mobile and are depleted with increasing of alteration degree, while Rb concentrates in sericitic rocks. Titanium, Zr, V, Ta, Nb, Th, U and LREE have inert behaviour during alteration. Alunite, APS minerals and rutile are the minerals that control the geochemistry of trace elements in the zones of advanced argillic alteration.
Carpathian Journal of Earth and Environmental Sciences
Increase of pollution of surface water and water sediments with hazardous substances (HSs) in the... more Increase of pollution of surface water and water sediments with hazardous substances (HSs) in the Danube River Basin requires implementation of systematic monitoring and evaluation of the sediment quality. The present study is focused on the ’South Danube’ Test Area (SDTA) that covers parts of the Lower Danube Basin in Romania, Serbia and Bulgaria. The SD area represents an extended region where Danube reaches its largest widths and depths and where pollution (industrial, mining, agricultural, waste etc.) from tributaries and land is supposed to accumulate in the sediments. Sampling of river bottom sediment (BS), suspended sediment (SS) and overbank (floodplain) sediment at two layers (0-5 cm in the top layer (FS TS) and 40-50 cm in the bottom layer (FS BS)), was carried out at 11 locations in order to analyze the concentration and distribution of 8 metal(oid)s (Cu, Pb, Zn, Cd, Hg, Ni, Cr, As), 6 polycyclic aromatic hydrocarbons (PAHs) and 6 pesticides as hazardous substances. The 2...
The supply of European critical raw materials (CRMs) does not currently meet the European demand.... more The supply of European critical raw materials (CRMs) does not currently meet the European demand. This gap is predicted to increase, making Europe even more dependent on outside suppliers. AGEMERA is a project to help tackle this strategic problem by studying several CRM sites in Finland, Poland, Spain, the Balkans, and Zambia in different deposit types. To check the potential of the porphyry systems in Europe as a source of CRMs, the Assarel porphyry-Cu deposit was chosen as a test site. Here we present preliminary geochemical and mineral chemistry data for hydrothermal ore and alteration minerals in Assarel that reveal the potential of the deposit to source some CRMs as by-products. Further studies will combine the geochemical data with innovative geophysical methods for an improved deposit model and provide enhanced knowledge about effective exploration techniques for CRMs.
In the present research, we have applied a combination of Cold-CL petrography with two in-situ te... more 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 later quartz-carbonate with chlorite. Together with the quartz and carbonates small amount of arsenian pyrite, hematite, chalcopyrite, sphalerite, galena and apatite are precipitated. SEM-EDS and LA-ICP-MS allowed determining that the observed zoning of the pyrite from Q-Py stage is due to a variable Co and Ni content. Similarly, the zonal growth of calcite is due to variable Mn content. Pyrite and arsenian pyrite have different trace element composition. Arsenian pyrite has elevated Au, Ag, Cu, Pb, Sb and Tl contents compared to the pyrite. The combination of the three techniques was essential for resolving temporal relationships between th...
The studied Silurian nodules have hard light cores and dark shells. The cores consist of quartz w... more The studied Silurian nodules have hard light cores and dark shells. The cores consist of quartz with disseminated zonal carbonate mineral and pyrite. Zones in the carbonate have a variable composition from Mn-containing siderite, ankerite and dolomite to mixed Fe-Mn carbonate and Fe-containing rhodochrosite. The nodule shells are composed of quartz, chlorite, sericite, goethite, Mn-Fe oxyhydroxides and siderite. Fe-Mn oxyhydroxides in the nodule shells are formed due to an alteration of the carbonate minerals and inherited their composition. The formation of the nodules with Fe- and Mn-carbonates is related to diagenetic processes under reducing conditions of low Eh and high pH values. Later, carbonate minerals were altered into Fe-Mn oxyhydroxides. These alteration changes can be related to the influence of later magmatic activity in the area. An example of this activity is the presence of an igneous bodies established on both sides of the section.
Carpathian Journal of Earth and Environmental Sciences, Aug 31, 2022
Concentration values higher than the thresholds for some of the PAHs (e.g. Fluoranthene) and some... more Concentration values higher than the thresholds for some of the PAHs (e.g. Fluoranthene) and sometimes for Total PAHs were also noted almost in every countries, caused by industrial activities, wastewater discharges or navigation on the Danube River. Pesticides were below the detection limit or below the legislative intervention thresholds at all national baseline sampling sites.
The distribution and behaviour of major and trace elements in the main zones of hydrothermal alte... more The distribution and behaviour of major and trace elements in the main zones of hydrothermal alteration (propylite, sericite and advanced argillic) in the area of Breznik Town have been studied, coupled with the chemical composition of alunite group minerals and their isotope geochemistry. The content of Sr decreases in propylite and especially in sericite rocks, and increases significantly in advanced argillic altered (AAA) rocks, which is connected with the formation of aluminium phosphate-sulphate (APS) minerals. Rubidium has high content in sericitic rocks, whereas the element is almost depleted in AAA rocks. The Rb/Sr ratio increases in sericitic rocks and strongly decreases in AAA rocks. Zirconium, Ti, Cr, V, Ga, Hf, Nb, Ta, Th, U and partially Sn and Ba have comparatively inert behaviour during alteration. Manganese, Zn, Ni, Co, Cs and Y are mobile in different degree, with a trend toward complete extraction in the most altered rocks. Arsenium concentrates in AAA rocks, while...
Our study is focused on REE and yttrium (REY) geochemistry of pore waters from core-box sediments... more Our study is focused on REE and yttrium (REY) geochemistry of pore waters from core-box sediments. The samples were collected from the 0–5 cm, 10–15 cm, 25–30 cm, and 35–40 cm depth intervals of four stations of the eastern part of block H_22 of IOM license area of the Clarion-Clipperton Fracture Zone, NE Pacific. The REE studies in marine pore fluids were limited by analytical challenges. The pore water analysis we applied is based on a modern, improved analytical technique (ICP-MS, Perkin-Elmer SCIEX Elan DRC-e) with a cross-flow nebulizer and a spectrometer optimized (RF, gas flow, lens voltage) using a quadrupole cell in a DRC (Dynamic Reaction Cell) mode that allowed us to define the whole suite of REE. The ƩREY values of the samples vary from 4.05 μg/l to 106.34 μg/l. The REE content is at least one order of magnitude higher than the oceanic water. We followed the natural variations of La, Lu, Ce, and Y in absolute concentrations for station 3607. Cerium and Y are slightly enr...
Geochemical features of the deep-sea sediments from a high polymetallic nodule area in the easter... more Geochemical features of the deep-sea sediments from a high polymetallic nodule area in the eastern part of the Clarion-Clipperton Fractures Zone (CCZ), NE Pacific were studied. Box-corer samples from six stations in individual depth layers 0–3, 3–5, 5–10, 10–20 cm were collected from 4300–4500 m depth. The deep-sea sediments were classified as clayey-siliceous oozes according to the mineral and grain-size analyses. The chemical composition of the studied samples is compatible with that of pelagic sediments. Manganese content varies from 0.16% to 0.70% being the highest in the geochemically active layer (top 7–12 cm) and decreases with depth. The Mn/Fe ratio, Ba, Co, Ni and Cu have the highest values in the first (0–3) and second (3–5) layers and decrease with depth. REE range is 195.84–357.79 ppm showing low variation between the layers. PAAS-normalized REE patterns show significant enrichment of MREE and HREE with strong negative Ce anomaly and weak positive Eu and Y anomalies. The...
The main goal of the present study is the characterization of the mineralogical and geochemical f... more The main goal of the present study is the characterization of the mineralogical and geochemical features of polymetallic (Mn- and Fe-bearing) nodules, lens- and layer-like bodies from different localities in the central part of the Late Cretaceous Srednogorie metallogenic zone, Bulgaria. The research is based on field studies, sampling and optical microscopy, followed by a combination of analytical techniques: XRD, SEM-EDS, ICP-OES and LA-ICP-MS methods. They define pyrolusite as the main ore mineral of the studied occurrences, while manganite, todorokite, bixbyite, sarkinite, hematite and hauerite are rarer. The most common gangue minerals are quartz, calcite and zeolites. Based on the MnO/SiO2 ratio, the established minerals are divided into two groups: manganese (i) and silica-manganese (ii) phases, respectively. Their trace element composition is dominated by a high content of V, Zn, Mo, W, Co, Ni, Cu, As, Tl and Sr, whereas some of them belong to the group of the critical raw m...
The distribution of major and trace elements in hydrothermal alteration zones (propylitic, argill... more The distribution of major and trace elements in hydrothermal alteration zones (propylitic, argillic, sericitic and advanced argillic) from the Asarel porphyry copper deposit is studied. Strontium was found to demonstrate the most characteristic behaviour among all studied elements – it is depleted from propylitic, argillic and sericitic rocks and concentrates in advanced argillic rocks where it is included in alunite and APS minerals. Manganese, Co, Ni, Zn, Cs, Y, MREE and HREE are strongly mobile and are depleted with increasing of alteration degree, while Rb concentrates in sericitic rocks. Titanium, Zr, V, Ta, Nb, Th, U and LREE have inert behaviour during alteration. Alunite, APS minerals and rutile are the minerals that control the geochemistry of trace elements in the zones of advanced argillic alteration.
Carpathian Journal of Earth and Environmental Sciences
Increase of pollution of surface water and water sediments with hazardous substances (HSs) in the... more Increase of pollution of surface water and water sediments with hazardous substances (HSs) in the Danube River Basin requires implementation of systematic monitoring and evaluation of the sediment quality. The present study is focused on the ’South Danube’ Test Area (SDTA) that covers parts of the Lower Danube Basin in Romania, Serbia and Bulgaria. The SD area represents an extended region where Danube reaches its largest widths and depths and where pollution (industrial, mining, agricultural, waste etc.) from tributaries and land is supposed to accumulate in the sediments. Sampling of river bottom sediment (BS), suspended sediment (SS) and overbank (floodplain) sediment at two layers (0-5 cm in the top layer (FS TS) and 40-50 cm in the bottom layer (FS BS)), was carried out at 11 locations in order to analyze the concentration and distribution of 8 metal(oid)s (Cu, Pb, Zn, Cd, Hg, Ni, Cr, As), 6 polycyclic aromatic hydrocarbons (PAHs) and 6 pesticides as hazardous substances. The 2...
The supply of European critical raw materials (CRMs) does not currently meet the European demand.... more The supply of European critical raw materials (CRMs) does not currently meet the European demand. This gap is predicted to increase, making Europe even more dependent on outside suppliers. AGEMERA is a project to help tackle this strategic problem by studying several CRM sites in Finland, Poland, Spain, the Balkans, and Zambia in different deposit types. To check the potential of the porphyry systems in Europe as a source of CRMs, the Assarel porphyry-Cu deposit was chosen as a test site. Here we present preliminary geochemical and mineral chemistry data for hydrothermal ore and alteration minerals in Assarel that reveal the potential of the deposit to source some CRMs as by-products. Further studies will combine the geochemical data with innovative geophysical methods for an improved deposit model and provide enhanced knowledge about effective exploration techniques for CRMs.
In the present research, we have applied a combination of Cold-CL petrography with two in-situ te... more 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 later quartz-carbonate with chlorite. Together with the quartz and carbonates small amount of arsenian pyrite, hematite, chalcopyrite, sphalerite, galena and apatite are precipitated. SEM-EDS and LA-ICP-MS allowed determining that the observed zoning of the pyrite from Q-Py stage is due to a variable Co and Ni content. Similarly, the zonal growth of calcite is due to variable Mn content. Pyrite and arsenian pyrite have different trace element composition. Arsenian pyrite has elevated Au, Ag, Cu, Pb, Sb and Tl contents compared to the pyrite. The combination of the three techniques was essential for resolving temporal relationships between th...
The studied Silurian nodules have hard light cores and dark shells. The cores consist of quartz w... more The studied Silurian nodules have hard light cores and dark shells. The cores consist of quartz with disseminated zonal carbonate mineral and pyrite. Zones in the carbonate have a variable composition from Mn-containing siderite, ankerite and dolomite to mixed Fe-Mn carbonate and Fe-containing rhodochrosite. The nodule shells are composed of quartz, chlorite, sericite, goethite, Mn-Fe oxyhydroxides and siderite. Fe-Mn oxyhydroxides in the nodule shells are formed due to an alteration of the carbonate minerals and inherited their composition. The formation of the nodules with Fe- and Mn-carbonates is related to diagenetic processes under reducing conditions of low Eh and high pH values. Later, carbonate minerals were altered into Fe-Mn oxyhydroxides. These alteration changes can be related to the influence of later magmatic activity in the area. An example of this activity is the presence of an igneous bodies established on both sides of the section.
Carpathian Journal of Earth and Environmental Sciences, Aug 31, 2022
Concentration values higher than the thresholds for some of the PAHs (e.g. Fluoranthene) and some... more Concentration values higher than the thresholds for some of the PAHs (e.g. Fluoranthene) and sometimes for Total PAHs were also noted almost in every countries, caused by industrial activities, wastewater discharges or navigation on the Danube River. Pesticides were below the detection limit or below the legislative intervention thresholds at all national baseline sampling sites.
The distribution and behaviour of major and trace elements in the main zones of hydrothermal alte... more The distribution and behaviour of major and trace elements in the main zones of hydrothermal alteration (propylite, sericite and advanced argillic) in the area of Breznik Town have been studied, coupled with the chemical composition of alunite group minerals and their isotope geochemistry. The content of Sr decreases in propylite and especially in sericite rocks, and increases significantly in advanced argillic altered (AAA) rocks, which is connected with the formation of aluminium phosphate-sulphate (APS) minerals. Rubidium has high content in sericitic rocks, whereas the element is almost depleted in AAA rocks. The Rb/Sr ratio increases in sericitic rocks and strongly decreases in AAA rocks. Zirconium, Ti, Cr, V, Ga, Hf, Nb, Ta, Th, U and partially Sn and Ba have comparatively inert behaviour during alteration. Manganese, Zn, Ni, Co, Cs and Y are mobile in different degree, with a trend toward complete extraction in the most altered rocks. Arsenium concentrates in AAA rocks, while...
Our study is focused on REE and yttrium (REY) geochemistry of pore waters from core-box sediments... more Our study is focused on REE and yttrium (REY) geochemistry of pore waters from core-box sediments. The samples were collected from the 0–5 cm, 10–15 cm, 25–30 cm, and 35–40 cm depth intervals of four stations of the eastern part of block H_22 of IOM license area of the Clarion-Clipperton Fracture Zone, NE Pacific. The REE studies in marine pore fluids were limited by analytical challenges. The pore water analysis we applied is based on a modern, improved analytical technique (ICP-MS, Perkin-Elmer SCIEX Elan DRC-e) with a cross-flow nebulizer and a spectrometer optimized (RF, gas flow, lens voltage) using a quadrupole cell in a DRC (Dynamic Reaction Cell) mode that allowed us to define the whole suite of REE. The ƩREY values of the samples vary from 4.05 μg/l to 106.34 μg/l. The REE content is at least one order of magnitude higher than the oceanic water. We followed the natural variations of La, Lu, Ce, and Y in absolute concentrations for station 3607. Cerium and Y are slightly enr...
Geochemical features of the deep-sea sediments from a high polymetallic nodule area in the easter... more Geochemical features of the deep-sea sediments from a high polymetallic nodule area in the eastern part of the Clarion-Clipperton Fractures Zone (CCZ), NE Pacific were studied. Box-corer samples from six stations in individual depth layers 0–3, 3–5, 5–10, 10–20 cm were collected from 4300–4500 m depth. The deep-sea sediments were classified as clayey-siliceous oozes according to the mineral and grain-size analyses. The chemical composition of the studied samples is compatible with that of pelagic sediments. Manganese content varies from 0.16% to 0.70% being the highest in the geochemically active layer (top 7–12 cm) and decreases with depth. The Mn/Fe ratio, Ba, Co, Ni and Cu have the highest values in the first (0–3) and second (3–5) layers and decrease with depth. REE range is 195.84–357.79 ppm showing low variation between the layers. PAAS-normalized REE patterns show significant enrichment of MREE and HREE with strong negative Ce anomaly and weak positive Eu and Y anomalies. The...
The main goal of the present study is the characterization of the mineralogical and geochemical f... more The main goal of the present study is the characterization of the mineralogical and geochemical features of polymetallic (Mn- and Fe-bearing) nodules, lens- and layer-like bodies from different localities in the central part of the Late Cretaceous Srednogorie metallogenic zone, Bulgaria. The research is based on field studies, sampling and optical microscopy, followed by a combination of analytical techniques: XRD, SEM-EDS, ICP-OES and LA-ICP-MS methods. They define pyrolusite as the main ore mineral of the studied occurrences, while manganite, todorokite, bixbyite, sarkinite, hematite and hauerite are rarer. The most common gangue minerals are quartz, calcite and zeolites. Based on the MnO/SiO2 ratio, the established minerals are divided into two groups: manganese (i) and silica-manganese (ii) phases, respectively. Their trace element composition is dominated by a high content of V, Zn, Mo, W, Co, Ni, Cu, As, Tl and Sr, whereas some of them belong to the group of the critical raw m...
Uploads
Papers by Atanas Hikov