Sorin Silviu Udubasa | University of Bucharest (original) (raw)

Papers by Sorin Silviu Udubasa

Research paper thumbnail of Hydrosaline melt inclusion provinces in Romania

Goldschmidt2022 abstracts, 2022

The Alpine metallogenetic provinces are the classic environments for hydrosaline melt inclusion f... more The Alpine metallogenetic provinces are the classic environments for hydrosaline melt inclusion from the Carpathians in Romania. P-T-X values from Neogene porphyry Cu-(Au)-(Mo) deposits in Metaliferi Mountains range between 320 o-1426 o C, 0.08-12.8kb, 39-89 wt% NaCl equiv., XNaCl= 0.17-0.64, considering heterogeneous trapping and post entrapment modifications. The Late Cretaceous porphyry Cu-(Mo)-(Au) deposits in Banat show lower values, with 150 o-300 o C, 20-30 wt% NaCl eq., and 1-3 kb pressure [1]. Hydrosaline melt inclusions occur in the Eastern Carpathians Miocene volcanic province, from SăpÂnţa, Nistru, Dăneşti, Ţibleş-Bran-Măgura Neagră, Toroioaga, Bȃrgău, Harghita Mountains and in the Late Cretaceous magmatic rocks from Bocşa and Vlădeasa, in veins and pegmatites. Skarns from Moldova Nouă and Oraviţa (in Banat), and Băişoara (in the North Apuseni Mountains), contain hydrosaline melt inclusions as well. Ditrău alkaline massif (Triassic) contains carbonic-rich hydrosaline melt inclusions in the ring zone associated with sulfide-REE mineralization and alkaline-hydrosaline melt/fluids in the central part, associated with porphyry Mo-(Nb) mineralization and skarns. Permian Highiş rhyolites and granites, with quartz veins and greisens, contain multiphase saline aqueous inclusions associated with sulfide and cassiterite. Upper Precambrian MVT-carbonate formation from Rodna-Guşet district includes isolated salt minerals and aggregates, and carbonic-hydrosaline fluid inclusions. Possible further targets for the hydrosaline melt inclusions are the pre-, and Variscan granitoids, the eclogites in the South Carpathians, the pegmatitic districts [2; Fig.1] and the Proterozoic and Caledonian sulfide deposits in the East Carpathians and Dobrogea. Hydrosaline solutions precipitated submarine halite in the Transylvanian basin and Subcarpathian zones during contemporaneous Plinian volcanic activity in Miocene. References [1]

Research paper thumbnail of The main types of gold deposits in Romania

Επιστημονική Επετηρίδα του Τμήματος Γεωλογίας (Α.Π.Θ.) - XIX Congress of CBGA, Thessaloniki, Greece, 2010, Abstr. Vol., Geologica Balcanica, 2010

Research paper thumbnail of Tectonic Evolution of the Supragetic Nappe in Eastern Southern Carpathians: Variscan Contraction and Jurassic Extension

Research paper thumbnail of Nanogold and its bearing on

Research paper thumbnail of Nanoparticles and bioavailability of minerals and metals

Research paper thumbnail of POSTER-Gold2019 CLATHRASIL

Research paper thumbnail of Connexion porphyre cuprifère–épithermaux de type low-sulfidation : analyse structurale et représentation 3D du secteur de Bolcana, monts Apuseni, Roumanie

Comptes Rendus Geoscience, 2005

Research paper thumbnail of Nanominerals and Their Bearing on Metals Uptake by Plants

In the frame of a project aiming at the identification of nanominerals, especially of gold and si... more In the frame of a project aiming at the identification of nanominerals, especially of gold and silver in the waste dumps, two area were selected for the study, i.e. Valea lui Stan ores in the Căpăţâna Mts. (AuCu-As) and Bădeanca Valley ores in the Leaota Mts. (Co-Ni-Bi-Ag-U). A combination of optical, chemical (AAS, ICP-AES) and structural methods (NGR, XRD, TEM/SAED) has been proved to be succesfull for such an attempt. New minerals have been identified in the two areas, i.e. uytenbogaardtite, greenockite, maghemite etc. (Valea lui Stan); lavendulan, maghemite, Mn-spinel, ferrihydrite etc. (Bădeanca Valley) not previously known, all of them being at nanometric scale. The presence of silver carbonates at nanometric scale is also worth of mentioning. At the beginning of the experimental uptake of metals by plants, metal-enriched neutral soils have been used. Zea mays and Trifolium repens seeds were separately planted in Au, U, Cu and As enriched soils (“artificial ores”). Except for ...

Research paper thumbnail of Minerals-, glassy-, globular opaque and fluid inclusions from metamorphic recrystallized “MVT” sulfide mineralization from Blazna-Guşet prospect, Rodna Mountains, Romania

Goldschmidt2021 abstracts

Research paper thumbnail of Is there a eutectic mixture of the halite daughter phase with sulphate± carbonate± phosphate± borate± fluoride in the hydrosaline melt inclusions from porphyry Cu-Au (±Mo) deposits in Metaliferi Mountains, Western Romania?

Goldschmidt2021 abstracts

Research paper thumbnail of Remnants of ”nelsonitic” Apatite as a Possible Source of Phosphorous from Epithermal and Porphyry Copper Deposits of Carpathians (Romania)

Research paper thumbnail of Research, assessment and management of the travertine resources from the Banpotoc-Carpinis deposit (South Apuseni Mts., Romania)

Gospodarka Surowcami Mineralnymi

Romania is not a large country but, due to the very complex geological structure, it has 110 mine... more Romania is not a large country but, due to the very complex geological structure, it has 110 mineral and power substances with identified and quantified resources and reserves. In time, the most numerous from these (82) have been exploited at the ground surface, in over 3,492 identified quarries and open pits. Travertine has been exploited since ancient times in Romania The exploitation of Brezinta (Mehedinti county) has been known since the Roman times. Although resources are found in many other zones, only two travertine deposits are presently exploited by Marmosim S.A.: Banpotoc-Carpinis and Geoagiu. Travertine extraction began at the Banpotoc-Carpinis deposit in 1870 and 9 quarries have functioned during time from which only one is still active today. This paper presents the way in which the research and valuation of the deposit was made, how the exploitation and processing of the travertine is made nowadays and what are its uses.

Research paper thumbnail of Nano-minerals identification by different physical techniques

Romanian Reports in Physics

The combined investigation techniques (EMPA, ME, NGR) evidenced the third level of the inclusions... more The combined investigation techniques (EMPA, ME, NGR) evidenced the third level of the inclusions at nano-size scale for different metamorphic deposits. So, NGR technique reveals the contribution of the (Mn, Fe) oxides - small particles at standard (RT) at very low temperature (LHeT) in the 57Fe - ray signal. On the other hand the ME techniques confirmed the presence of the nanometric Fe and Mn oxides inclusions in manganoan fayalites (Razoare deposit) and “coral like” aggregates of nanometric Au -“solid- bubbles” in the gold ores of the Southern Carpathians.

Research paper thumbnail of Parageneses and geochemistry of gold from Valea lui Stan and Costesti ores, Southern Carpathians, Romania

Research paper thumbnail of Nanogold and its bearing on “invisible gold” in sulfides

Natural gold shows a great variety of forms and size, mainly due to its high chemical stability a... more Natural gold shows a great variety of forms and size, mainly due to its high chemical stability and mechanical coherence. In addition to macro- and microgold it was shown that nanogold might also exist, as a supplementary alternative to the “invisible gold”, supposedly substituting for As and Fe, e.g. in arsenopyrite (see Cathelineau et al., 1989, and many others thereafter). Nanogold forms both spherical, isolated grains and coral-like aggregates, several nanometers and tens of nanometers in size, respectively. It was first detected on grain surfaces of nearly all the sulfides present in some small-size shear-zone related gold ores in metamorphics, however with a preference for arsenopyrite and pyrite.

Research paper thumbnail of How to detect submicroscopic minerals and their bearing on the extension of the mineral parageneses

Annually some 50-60 new mineral species are discovered, a fact exceeding the number of discredite... more Annually some 50-60 new mineral species are discovered, a fact exceeding the number of discredited (mostly old) mineral species. As a result, about 4000 to 4200 valid mineral species are officially registered by IMA by its very active CNMNC (Commission on New Minerals, Nomenclature and Classification). About 75-80 % of the newly described mineral species are submicroscopic compounds (almost exclusively meteorite minerals), which can be detected only by using structural techniques such as EPMA, NGR, TEM/SAED, HRTEM, AEM, XRD, etc.

Research paper thumbnail of Nanominerals and their bearing on metals uptake by plants

In the frame of a project aiming at the identification of nanominerals, especially of gold and si... more In the frame of a project aiming at the identification of nanominerals, especially of gold and silver in the waste dumps, two area were selected for the study, i.e. Valea lui Stan ores in the Căpăţâna Mts. (Au- Cu-As) and Bădeanca Valley ores in the Leaota Mts. (Co-Ni-Bi-Ag-U). A combination of optical, chemical (AAS, ICP-AES) and structural methods (NGR, XRD, TEM/SAED) has been proved to be succesfull for such an attempt. New minerals have been identified in the two areas, i.e. uytenbogaardtite, greenockite, maghemite etc. (Valea lui Stan); lavendulan, maghemite, Mn-spinel, ferrihydrite etc. (Bădeanca Valley) not previously known, all of them being at nanometric scale. The presence of silver carbonates at nanometric scale is also worth of mentioning. At the beginning of the experimental uptake of metals by plants, metal-enriched neutral soils have been used. Zea mays and Trifolium repens seeds were separately planted in Au, U, Cu and As enriched soils (“artificial ores”). Except fo...

Research paper thumbnail of A complex investigations of the iron and gold inclusions in mineral species at nanosize scale

Romanian Journal of Physics

The combined investigation techniques, electron probe microanalysis (EPMA), Mössbauer spectroscop... more The combined investigation techniques, electron probe microanalysis (EPMA), Mössbauer spectroscopy (NGR), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD),) evidenced the third level of the inclusions at nanosize scale for specific minerals of different Romanian metamorphic deposits. So, NGR technique reveals the contribution of the (Mn, Fe) oxides - small particles at standard (RT) and at very low temperature (LHeT) in the 57Fe γ - ray signal of manganoan-fayalites (Razoare deposit). The EM analysis techniques confirmed the presence of the nanometric Fe and Mn oxides inclusions in manganoan fayalites, as well as of pyroxferroite (Razoare deposit). On the other hand, an extensive investigation of the gold ores in the South Carpathians (Costesti, Valea lui Stan and Jidostita) has been performed by using a fruitful combination among the above mentioned complementary mineralogical and structural methods. The investigation of the...

Research paper thumbnail of Research on Gabbros from Cazanesti - Ciungani, Romania, in Order to Identify New Recovery Directions

Gabbros are mafic igneous rocks (45 -52% SiO 2), plutonic type. These rocks have been formed at g... more Gabbros are mafic igneous rocks (45 -52% SiO 2), plutonic type. These rocks have been formed at great depths with slight variations of temperature and pressure. The degree of crystallinity (holocrystalline rocks -complete crystallized mass), the absolute crystals size (phaneritic rocks -crystals larger than 2 mm), varied mineralization and useful elements led to a high economic interest on the gabbros exploitation. Usually, gabbros are investigated mainly in order to exploit iron, titanium, vanadium, and its use in architectural constructions, ornamental rocks and monuments. However, through extensive research it was observed that gabbros often contain significant amounts of chromium, nickel, copper, cobalt, gold, silver and platinum. Thus, increasing of scientific and technological performance have led to the concern of developing new methods for these elements recovery.

Research paper thumbnail of Structural (ME, XRD, NGR, ESR) investigations on some sulphides from Costesti, Valea lui Stan and Jidostita gold ores (Southern Carpathians, Romania)

Romanian Journal of Physics

An extensive investigation of the gold ores in the South Carpathians (Costesti, Valea lui Stan si... more An extensive investigation of the gold ores in the South Carpathians (Costesti, Valea lui Stan si Jidostita) has performed, using different chemical and physics experimental techniques. The used structural techniques have been the electron microscopy, X-ray diffraction, Mössbauer effect and electron spin resonance. The investigation of the representative samples by the structural techniques relieved new minerals in the gold ores, the presence of the "coral like" aggregates of nanometric gold solid bubbles.

Research paper thumbnail of Hydrosaline melt inclusion provinces in Romania

Goldschmidt2022 abstracts, 2022

The Alpine metallogenetic provinces are the classic environments for hydrosaline melt inclusion f... more The Alpine metallogenetic provinces are the classic environments for hydrosaline melt inclusion from the Carpathians in Romania. P-T-X values from Neogene porphyry Cu-(Au)-(Mo) deposits in Metaliferi Mountains range between 320 o-1426 o C, 0.08-12.8kb, 39-89 wt% NaCl equiv., XNaCl= 0.17-0.64, considering heterogeneous trapping and post entrapment modifications. The Late Cretaceous porphyry Cu-(Mo)-(Au) deposits in Banat show lower values, with 150 o-300 o C, 20-30 wt% NaCl eq., and 1-3 kb pressure [1]. Hydrosaline melt inclusions occur in the Eastern Carpathians Miocene volcanic province, from SăpÂnţa, Nistru, Dăneşti, Ţibleş-Bran-Măgura Neagră, Toroioaga, Bȃrgău, Harghita Mountains and in the Late Cretaceous magmatic rocks from Bocşa and Vlădeasa, in veins and pegmatites. Skarns from Moldova Nouă and Oraviţa (in Banat), and Băişoara (in the North Apuseni Mountains), contain hydrosaline melt inclusions as well. Ditrău alkaline massif (Triassic) contains carbonic-rich hydrosaline melt inclusions in the ring zone associated with sulfide-REE mineralization and alkaline-hydrosaline melt/fluids in the central part, associated with porphyry Mo-(Nb) mineralization and skarns. Permian Highiş rhyolites and granites, with quartz veins and greisens, contain multiphase saline aqueous inclusions associated with sulfide and cassiterite. Upper Precambrian MVT-carbonate formation from Rodna-Guşet district includes isolated salt minerals and aggregates, and carbonic-hydrosaline fluid inclusions. Possible further targets for the hydrosaline melt inclusions are the pre-, and Variscan granitoids, the eclogites in the South Carpathians, the pegmatitic districts [2; Fig.1] and the Proterozoic and Caledonian sulfide deposits in the East Carpathians and Dobrogea. Hydrosaline solutions precipitated submarine halite in the Transylvanian basin and Subcarpathian zones during contemporaneous Plinian volcanic activity in Miocene. References [1]

Research paper thumbnail of The main types of gold deposits in Romania

Επιστημονική Επετηρίδα του Τμήματος Γεωλογίας (Α.Π.Θ.) - XIX Congress of CBGA, Thessaloniki, Greece, 2010, Abstr. Vol., Geologica Balcanica, 2010

Research paper thumbnail of Tectonic Evolution of the Supragetic Nappe in Eastern Southern Carpathians: Variscan Contraction and Jurassic Extension

Research paper thumbnail of Nanogold and its bearing on

Research paper thumbnail of Nanoparticles and bioavailability of minerals and metals

Research paper thumbnail of POSTER-Gold2019 CLATHRASIL

Research paper thumbnail of Connexion porphyre cuprifère–épithermaux de type low-sulfidation : analyse structurale et représentation 3D du secteur de Bolcana, monts Apuseni, Roumanie

Comptes Rendus Geoscience, 2005

Research paper thumbnail of Nanominerals and Their Bearing on Metals Uptake by Plants

In the frame of a project aiming at the identification of nanominerals, especially of gold and si... more In the frame of a project aiming at the identification of nanominerals, especially of gold and silver in the waste dumps, two area were selected for the study, i.e. Valea lui Stan ores in the Căpăţâna Mts. (AuCu-As) and Bădeanca Valley ores in the Leaota Mts. (Co-Ni-Bi-Ag-U). A combination of optical, chemical (AAS, ICP-AES) and structural methods (NGR, XRD, TEM/SAED) has been proved to be succesfull for such an attempt. New minerals have been identified in the two areas, i.e. uytenbogaardtite, greenockite, maghemite etc. (Valea lui Stan); lavendulan, maghemite, Mn-spinel, ferrihydrite etc. (Bădeanca Valley) not previously known, all of them being at nanometric scale. The presence of silver carbonates at nanometric scale is also worth of mentioning. At the beginning of the experimental uptake of metals by plants, metal-enriched neutral soils have been used. Zea mays and Trifolium repens seeds were separately planted in Au, U, Cu and As enriched soils (“artificial ores”). Except for ...

Research paper thumbnail of Minerals-, glassy-, globular opaque and fluid inclusions from metamorphic recrystallized “MVT” sulfide mineralization from Blazna-Guşet prospect, Rodna Mountains, Romania

Goldschmidt2021 abstracts

Research paper thumbnail of Is there a eutectic mixture of the halite daughter phase with sulphate± carbonate± phosphate± borate± fluoride in the hydrosaline melt inclusions from porphyry Cu-Au (±Mo) deposits in Metaliferi Mountains, Western Romania?

Goldschmidt2021 abstracts

Research paper thumbnail of Remnants of ”nelsonitic” Apatite as a Possible Source of Phosphorous from Epithermal and Porphyry Copper Deposits of Carpathians (Romania)

Research paper thumbnail of Research, assessment and management of the travertine resources from the Banpotoc-Carpinis deposit (South Apuseni Mts., Romania)

Gospodarka Surowcami Mineralnymi

Romania is not a large country but, due to the very complex geological structure, it has 110 mine... more Romania is not a large country but, due to the very complex geological structure, it has 110 mineral and power substances with identified and quantified resources and reserves. In time, the most numerous from these (82) have been exploited at the ground surface, in over 3,492 identified quarries and open pits. Travertine has been exploited since ancient times in Romania The exploitation of Brezinta (Mehedinti county) has been known since the Roman times. Although resources are found in many other zones, only two travertine deposits are presently exploited by Marmosim S.A.: Banpotoc-Carpinis and Geoagiu. Travertine extraction began at the Banpotoc-Carpinis deposit in 1870 and 9 quarries have functioned during time from which only one is still active today. This paper presents the way in which the research and valuation of the deposit was made, how the exploitation and processing of the travertine is made nowadays and what are its uses.

Research paper thumbnail of Nano-minerals identification by different physical techniques

Romanian Reports in Physics

The combined investigation techniques (EMPA, ME, NGR) evidenced the third level of the inclusions... more The combined investigation techniques (EMPA, ME, NGR) evidenced the third level of the inclusions at nano-size scale for different metamorphic deposits. So, NGR technique reveals the contribution of the (Mn, Fe) oxides - small particles at standard (RT) at very low temperature (LHeT) in the 57Fe - ray signal. On the other hand the ME techniques confirmed the presence of the nanometric Fe and Mn oxides inclusions in manganoan fayalites (Razoare deposit) and “coral like” aggregates of nanometric Au -“solid- bubbles” in the gold ores of the Southern Carpathians.

Research paper thumbnail of Parageneses and geochemistry of gold from Valea lui Stan and Costesti ores, Southern Carpathians, Romania

Research paper thumbnail of Nanogold and its bearing on “invisible gold” in sulfides

Natural gold shows a great variety of forms and size, mainly due to its high chemical stability a... more Natural gold shows a great variety of forms and size, mainly due to its high chemical stability and mechanical coherence. In addition to macro- and microgold it was shown that nanogold might also exist, as a supplementary alternative to the “invisible gold”, supposedly substituting for As and Fe, e.g. in arsenopyrite (see Cathelineau et al., 1989, and many others thereafter). Nanogold forms both spherical, isolated grains and coral-like aggregates, several nanometers and tens of nanometers in size, respectively. It was first detected on grain surfaces of nearly all the sulfides present in some small-size shear-zone related gold ores in metamorphics, however with a preference for arsenopyrite and pyrite.

Research paper thumbnail of How to detect submicroscopic minerals and their bearing on the extension of the mineral parageneses

Annually some 50-60 new mineral species are discovered, a fact exceeding the number of discredite... more Annually some 50-60 new mineral species are discovered, a fact exceeding the number of discredited (mostly old) mineral species. As a result, about 4000 to 4200 valid mineral species are officially registered by IMA by its very active CNMNC (Commission on New Minerals, Nomenclature and Classification). About 75-80 % of the newly described mineral species are submicroscopic compounds (almost exclusively meteorite minerals), which can be detected only by using structural techniques such as EPMA, NGR, TEM/SAED, HRTEM, AEM, XRD, etc.

Research paper thumbnail of Nanominerals and their bearing on metals uptake by plants

In the frame of a project aiming at the identification of nanominerals, especially of gold and si... more In the frame of a project aiming at the identification of nanominerals, especially of gold and silver in the waste dumps, two area were selected for the study, i.e. Valea lui Stan ores in the Căpăţâna Mts. (Au- Cu-As) and Bădeanca Valley ores in the Leaota Mts. (Co-Ni-Bi-Ag-U). A combination of optical, chemical (AAS, ICP-AES) and structural methods (NGR, XRD, TEM/SAED) has been proved to be succesfull for such an attempt. New minerals have been identified in the two areas, i.e. uytenbogaardtite, greenockite, maghemite etc. (Valea lui Stan); lavendulan, maghemite, Mn-spinel, ferrihydrite etc. (Bădeanca Valley) not previously known, all of them being at nanometric scale. The presence of silver carbonates at nanometric scale is also worth of mentioning. At the beginning of the experimental uptake of metals by plants, metal-enriched neutral soils have been used. Zea mays and Trifolium repens seeds were separately planted in Au, U, Cu and As enriched soils (“artificial ores”). Except fo...

Research paper thumbnail of A complex investigations of the iron and gold inclusions in mineral species at nanosize scale

Romanian Journal of Physics

The combined investigation techniques, electron probe microanalysis (EPMA), Mössbauer spectroscop... more The combined investigation techniques, electron probe microanalysis (EPMA), Mössbauer spectroscopy (NGR), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD),) evidenced the third level of the inclusions at nanosize scale for specific minerals of different Romanian metamorphic deposits. So, NGR technique reveals the contribution of the (Mn, Fe) oxides - small particles at standard (RT) and at very low temperature (LHeT) in the 57Fe γ - ray signal of manganoan-fayalites (Razoare deposit). The EM analysis techniques confirmed the presence of the nanometric Fe and Mn oxides inclusions in manganoan fayalites, as well as of pyroxferroite (Razoare deposit). On the other hand, an extensive investigation of the gold ores in the South Carpathians (Costesti, Valea lui Stan and Jidostita) has been performed by using a fruitful combination among the above mentioned complementary mineralogical and structural methods. The investigation of the...

Research paper thumbnail of Research on Gabbros from Cazanesti - Ciungani, Romania, in Order to Identify New Recovery Directions

Gabbros are mafic igneous rocks (45 -52% SiO 2), plutonic type. These rocks have been formed at g... more Gabbros are mafic igneous rocks (45 -52% SiO 2), plutonic type. These rocks have been formed at great depths with slight variations of temperature and pressure. The degree of crystallinity (holocrystalline rocks -complete crystallized mass), the absolute crystals size (phaneritic rocks -crystals larger than 2 mm), varied mineralization and useful elements led to a high economic interest on the gabbros exploitation. Usually, gabbros are investigated mainly in order to exploit iron, titanium, vanadium, and its use in architectural constructions, ornamental rocks and monuments. However, through extensive research it was observed that gabbros often contain significant amounts of chromium, nickel, copper, cobalt, gold, silver and platinum. Thus, increasing of scientific and technological performance have led to the concern of developing new methods for these elements recovery.

Research paper thumbnail of Structural (ME, XRD, NGR, ESR) investigations on some sulphides from Costesti, Valea lui Stan and Jidostita gold ores (Southern Carpathians, Romania)

Romanian Journal of Physics

An extensive investigation of the gold ores in the South Carpathians (Costesti, Valea lui Stan si... more An extensive investigation of the gold ores in the South Carpathians (Costesti, Valea lui Stan si Jidostita) has performed, using different chemical and physics experimental techniques. The used structural techniques have been the electron microscopy, X-ray diffraction, Mössbauer effect and electron spin resonance. The investigation of the representative samples by the structural techniques relieved new minerals in the gold ores, the presence of the "coral like" aggregates of nanometric gold solid bubbles.