Stefan Marincea

Geological Institute of Romania | IGR · Mineralogy

A carbonate-bearing, fluorine-overcompensated fluorapatite (F = 4.42 wt.% as compared with 3.77 wt.% F in the Ca5(PO4)3F end-member), was identified in forsterite-bearing skarns from Valea Rea (N 46°39′48″, E 22°36′43″), located near the contact of the granodiorite laccolith from Budureasa, of Upper Cretaceous Age, with Anisian dolostones. The chem...

The rare minerals, inesite, Ca2Mn 2+ 7Si10O28(OH)2·5H2O, hubeite, Ca2Mn 2+ Fe 3+ Si4O12(OH)·2H2O, and ruizite, Ca2Mn 3+ Si4O11(OH)4·2H2O, were determined, for the first time, by optical and XRD analyses, at Cavnic (Baia Mare Neogene metallogenetic district, Eastern Carpathians, Romania) in a gold-bearing, base metal deposit. Inesite was refined as...

This paper describes the results of the CHPM2030 research project, which was running in the period 2016-2019. It was funded through the European Commission Horizon 2020 programme with the aim to develop a novel and potentially disruptive technology solution that can help satisfy the European needs for energy and strategic metals in a single interli...

A rich association of primary guano minerals, including taranakite, hydroxylapatite, brushite and gypsum with relicts of illite, kaolinite, alpha (low) quartz and calcite, was identified in the fossil bat guano deposit from Gura Dobrogei Cave, Dobrogea County, Romania. Gypsum and Ca phosphates developed preferentially on the carbonate bedrock or on...

A shallow-level monzodioritic to quartz-monzodioritic pluton of the Upper Cretaceous age caused contact metamorphism of Tithonic-Kimmeridgian reef limestones at Măgureaua Vaţei (Metaliferi Massif, Apuseni Mountains, Romania). The preserved peak metamorphic assemblage includes gehlenite (Ak 33.64-38.13), monticellite, wollastonite-2M, Ti-poor calcic...

The Albeşti granite, of Early Ordovician age, was formed by crustal anatexis, experienced a medium temperature and medium-to-high pressure metamorphic event and is now hosted by the crystalline formations of the Leaota Mountains (South Carpathians), where it forms stratigraphically concordant lenses. Its most striking feature, similar to other Euro...

The Early Ordovician Albești Granite was formed by crustal anatexis, experienced a medium temperature and medium to high pressure metamorphic event and is now hosted by the crystalline formations of the Leaota Mts. (South Carpathians) where it forms stratigraphically concordant lenses. Its most striking feature, similar to other European granites o...

Szaibelyite samples from five boron-bearing magnesian skarns in Romania (Ocna de Fier, Maşca-Băişoara, Cacova Ierii, Băiţa Bihor and Pietroasa) were analysed in order to improve on optical, chemical, thermal, infrared and X-ray database. In all the five occurrences, the mineral is present in the outer skarn zones developed at the contact of igneous...

Phosphogypsum is a technogenic product resulted after the extraction of phosphoric acid from raw phosphate (apatitic) rock by nitric or sulfuric leaching. In Romania, huge stacks of phosphogypsum resulted from sulfuric leaching are located at Valea Călugărească (56 ha), Turnu Măgurele (64 ha), Năvodari (48 ha) and Bacău (20 ha). The chemistry of di...

The National Museum of Geology of Romania is hosted by the historical building of the Geological Institute of Romania, declared a monument of architecture and erected in 1906 - 1909. The museum encapsulates all the branches of the geological sciences (which are shown as if illustrating a treatise of geology) and posesses 85000 exhibits. The 22 hall...

The present study highlights the fact that having the mark of the rocks through which they pass, geothermal waters from Beius Basin have, in their natural state, an important content of metals. This fact encourages us to believe that, through anthropic methods, it is possible to increase even more this content of metals in the exploited geothermal...

Diatomite samples taken from the Urluia – Adamclisi localities, South Dobrogea region (Romania) have been studied by X-ray fluorescence, wet-chemical analysis, scanning electron microscopy (SEM), FTIR and X-ray powder diffraction. The mineralogy of all but one deposit is predominated by the presence of quartz, amorphous silica, feldspars and clay m...

Detailed information concerning the pre-and post-burial modifications that affect the remains of ancient organisms (i.e. their taphonomy) are instrumental in appreciating the ways the fossil record is biased by biological and geological processes. Reconstructing taphonomic history also allows a more accurate understanding of the paleoenvironmental...

A shallow-level dioritic pluton of Upper Cretaceous age caused extensive contact metamorphism of a Mesozoic calcareous sequence at Oraviţa-Ciclova in Romania. The peak metamorphic assemblage (stage I) includes wollastonite, åkermanite-rich melilite, Ti-rich calcic garnet, and pyrrhotite. A second, subsequent paragenesis (stage II) is due to local d...

Ardealite from Cioclovina was first described by Schadler (1932) from the fossil bat-guano deposit in the "dry" Cioclovina Cave (Şureanu Mountains, Romania). The mineral occurs as white pearly or earthy masses of chalky appearance. Our investigation shows that the mineral can be characterized as a P-substituted sulfate. Wet-chemical and ICP-AES ana...

A shallow-level monzodioritic to quartz-monzodioritic pluton of Upper Cretaceous age caused extensive contact metamorphism of Tithonic - Kimmeridgian reef limestones at Măgureaua Vaţei (Metaliferi Massif, Apuseni Mountains, Romania). The preserved peak metamorphic assemblage includes gehlenite, monticellite, wollastonite-2M, Ti-poor calcic garnet,...

In the Banat area, the contact metamorphism is related to various shallow level magmatic intrusions of Upper Cretaceous age, that lead in the Ciclova – Oraviţa zone to the formation of some particular, high-temperature calc-skarns deposits. Gehlenite-bearing skarns occur at the very contact between dioritic or monzodioritic bodies and carbonaceous...

Wollastonite from three occurrences of high-temperature skarns in Romania: Măgureaua Vaţei (MV), Cornet Hill (CH) and Oraviţa (Or), was investigated from crystal-chemical and crystallographical point of view, in order to assay its use as industrial mineral. In all cases, wollastonite-2M occurs in gehlenite-bearing skarns within the contact between...

Diatomaceous earths from six occurrences in Romania were analyzed from chemical and mineralogical point of view in order to check the optimal deposit for providing absorbers and filtration media for essential oils. The characterization was done using X-ray fluorescence, wet-chemical analysis, FTIR and X-ray powder diffraction. The target occurrence...

Gatehouseite, Mn5(PO4)2(OH)4, is a rare Mn-bearing phosphate, since this mineral is only reported in a sedimentary iron ore deposit in Australia (Pring and Birch, 1993). Like in many Mn-bearing phosphates structures, Fe may replace Mn and a complete solid solution often exists between the Mn- and Fe-bearing end-members. One more time, our work lead...

project number PN-II-RU-PD-2011-3-0172 and by ERA-MIN projects (SUSMIN and MAXI). Table 1. Trace element contents in minerals from Roşia Poieni porphyry copper deposit using EMPA method (Cioacă et al., 2014) Mineral (no. of measurements) Au (ppm) Ag (ppm) Te (ppm) As (ppm) Bi (ppm) Se (ppm) Pyrite (9) 20 <10 <20 50 nm 21 Chalcopyrite (2) <200 125 <...

The cave from Gura Dobrogei is located in Constanta County, Dobrogea Region, Romania, at about 3 km to the West from the homonymous locality, and about 40 km N-NW from Constanta, the major city in the area. The cave is also known as the ”Bat Cave” (Pestera Liliecilor) from Gura Dobrogei. It seems to represent an upper (fossil) level of a karstic sy...

A shallow-level dioritic pluton of Upper Cretaceous age caused extensive contact metamorphism of a Callovian - Aptian calcareous sequence at Oraviţa - Ciclova (Banat, Romania), at about 35 km SSW of Reşita, the major city in the area. The resulted high-temperature skarn can be better observed on Crişenilor Brook, where it crops out at about 200 m u...

Phosphogypsum is a technogenic product remaining after the extraction of phosphoric acid from raw phosphate, mainly apatite. The phosphate rock mainly composed of apatite, and originating from Morocco, Russia, Syria, Jordan and India, is treated with concentrated sulfuric acid (96%), after fine crushing to supra colloidal size and passing into an a...

Insignificant in terms of mineralization, the skarns of Oravita are scientifically interested because of their mineralogical associations. The higher crystallinity and good natural conditions (they are generally barren) are two characteristics of this rocks that can provide the ideally system to understand the behavior of the mineralogical componen...

Phosphogypsum is a technogenic product remaining after the extraction of phosphoric acid from raw phosphate, mainly apatite. The original phosphate rock contains large amounts of REE, mainly replacing Ca from apatite or included in other phosphate structures. About 70% of the REE contents are stacked in the phosphogypsum obtained after sulfuric att...

The high-temperature skarn of Cornet Hill (Apuseni Mountains, Romania) is known as one of the rare occurrences of spurrite and tilleyite worldwide. Both minerals concentrate in the outer skarn zone, corresponding to the exoskarn, at the contact between a monzodiorite-quartz monzonite body of Upper Cretaceous age and Tithonic-Kimmeridgian reef limes...

Gehlenite is a common mineral in three high-temperature calcic skarns in Romania: Magureaua Vatei and Cornet Hill in Apuseni Mountains and Oravita in Banat. In all three occurrences, a gehlenite zone occurs within the contact between dioritic or monzodioritic bodies of Upper Cretaceous age and carbonaceous sequences of Mesozoic age. The melilite so...