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1

Castrillón, Andrés, et Javier Guerrero. « Listvenites : new insights of a hydrothermal system fossilized in Cerro Matoso peridotites, Montelíbano, Córdoba Department, Colombia ». Boletín Geológico, no 47 (23 décembre 2020) : 67–84. http://dx.doi.org/10.32685/0120-1425/boletingeo.47.2020.492.

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The products of metasomatic alteration (e.g., carbonation) of peridotites are called listvenites. Based on a description of the outcrops in the laterite deposit at Cerro Matoso located in the NW of Colombia, the mineralogical composition confirmed by petrography, and a chemical analysis performed with XRF and WDS/EDS, the previous unit called tachylite is redefined as listvenite. Two types of listvenites are described: listvenite A, with the mineralogical association of quartz + siderite + phyllosilicates + goethite +/- magnetite, and listvenite B, with the association of siderite + phyllosilicates + goethite. Cr-spinel relics accompanied by Mn-siderite and neoblastic textures, indicate their origin from peridotites, where Mn-Fe would have been deposited by hydrothermal fluids. Hydrothermal reducing environments with alkaline fluids and low temperatures should have favored the formation of listvenites that are observed along a fracture zone, oriented WNW-ESE at Pit-1 in Cerro Matoso. Due to exposure to climatic conditions since the Eocene, but definitively since the last Andean Orogeny, listvenites were affected, like all the rocks in the Cerro Matoso deposit, by intense supergene weathering and leaching processes, which could make their true origin unclear.
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Beiranvand Pour, Amin, Yongcheol Park, Laura Crispini, Andreas Läufer, Jong Kuk Hong, Tae-Yoon S. Park, Basem Zoheir et al. « Mapping Listvenite Occurrences in the Damage Zones of Northern Victoria Land, Antarctica Using ASTER Satellite Remote Sensing Data ». Remote Sensing 11, no 12 (13 juin 2019) : 1408. http://dx.doi.org/10.3390/rs11121408.

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Listvenites normally form during hydrothermal/metasomatic alteration of mafic and ultramafic rocks and represent a key indicator for the occurrence of ore mineralizations in orogenic systems. Hydrothermal/metasomatic alteration mineral assemblages are one of the significant indicators for ore mineralizations in the damage zones of major tectonic boundaries, which can be detected using multispectral satellite remote sensing data. In this research, Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) multispectral remote sensing data were used to detect listvenite occurrences and alteration mineral assemblages in the poorly exposed damage zones of the boundaries between the Wilson, Bowers and Robertson Bay terranes in Northern Victoria Land (NVL), Antarctica. Spectral information for detecting alteration mineral assemblages and listvenites were extracted at pixel and sub-pixel levels using the Principal Component Analysis (PCA)/Independent Component Analysis (ICA) fusion technique, Linear Spectral Unmixing (LSU) and Constrained Energy Minimization (CEM) algorithms. Mineralogical assemblages containing Fe2+, Fe3+, Fe-OH, Al-OH, Mg-OH and CO3 spectral absorption features were detected in the damage zones of the study area by implementing PCA/ICA fusion to visible and near infrared (VNIR) and shortwave infrared (SWIR) bands of ASTER. Silicate lithological groups were mapped and discriminated using PCA/ICA fusion to thermal infrared (TIR) bands of ASTER. Fraction images of prospective alteration minerals, including goethite, hematite, jarosite, biotite, kaolinite, muscovite, antigorite, serpentine, talc, actinolite, chlorite, epidote, calcite, dolomite and siderite and possible zones encompassing listvenite occurrences were produced using LSU and CEM algorithms to ASTER VNIR+SWIR spectral bands. Several potential zones for listvenite occurrences were identified, typically in association with mafic metavolcanic rocks (Glasgow Volcanics) in the Bowers Mountains. Comparison of the remote sensing results with geological investigations in the study area demonstrate invaluable implications of the remote sensing approach for mapping poorly exposed lithological units, detecting possible zones of listvenite occurrences and discriminating subpixel abundance of alteration mineral assemblages in the damage zones of the Wilson-Bowers and Bowers-Robertson Bay terrane boundaries and in intra-Bowers and Wilson terranes fault zones with high fluid flow. The satellite remote sensing approach developed in this research is explicitly pertinent to detecting key alteration mineral indicators for prospecting hydrothermal/metasomatic ore minerals in remote and inaccessible zones situated in other orogenic systems around the world.
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Sofiya, Ayano, Akira Ishiwatari, Naoto Hirano et Tatsuki Tsujimori. « Relict chromian spinels in Tulu Dimtu serpentinites and listvenite, Western Ethiopia : implications for the timing of listvenite formation ». International Geology Review 59, no 13 (5 août 2016) : 1621–31. http://dx.doi.org/10.1080/00206814.2016.1213142.

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Menzel, Manuel D., Janos L. Urai, Estibalitz Ukar, Thierry Decrausaz et Marguerite Godard. « Progressive veining during peridotite carbonation : insights from listvenites in Hole BT1B, Samail ophiolite (Oman) ». Solid Earth 13, no 8 (1 août 2022) : 1191–218. http://dx.doi.org/10.5194/se-13-1191-2022.

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Abstract. The reaction of serpentinized peridotite with CO2-bearing fluids to form listvenite (quartz–carbonate rock) requires massive fluid flux and significant permeability despite an increase in solid volume. Listvenite and serpentinite samples from Hole BT1B of the Oman Drilling Project help to understand mechanisms and feedbacks during vein formation in this process. Samples analyzed in this study contain abundant magnesite veins in closely spaced, parallel sets and younger quartz-rich veins. Cross-cutting relationships suggest that antitaxial, zoned magnesite veins with elongated grains growing from a median zone towards the wall rock are among the earliest structures to form during carbonation of serpentinite. Their bisymmetric chemical zoning of variable Ca and Fe contents, a systematic distribution of SiO2 and Fe-oxide inclusions in these zones, and cross-cutting relations with Fe oxides and Cr spinel indicate that they record progress of reaction fronts during replacement of serpentine by carbonate in addition to dilatant vein growth. Euhedral terminations and growth textures of magnesite vein fill, together with local dolomite precipitation and voids along the vein–wall rock interface, suggest that these veins acted as preferred fluid pathways allowing infiltration of CO2-rich fluids necessary for carbonation to progress. Fracturing and fluid flow were probably further enabled by external tectonic stress, as indicated by closely spaced sets of subparallel carbonate veins. Despite widespread subsequent quartz mineralization in the rock matrix and veins, which most likely caused a reduction in the permeability network, carbonation proceeded to completion within listvenite horizons.
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QIU, Tian, et Yongfeng ZHU. « Gold Mineralization in Listvenite, the Sayi Gold Deposit, Xinjiang ». Acta Geologica Sinica - English Edition 88, s2 (décembre 2014) : 108–9. http://dx.doi.org/10.1111/1755-6724.12368_20.

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6

Onishchenko, S. A., et A. A. Soboleva. « Apoultramafic metasomatites of the Enganepe Uplift (the Polar Urals) ». Vestnik of Geosciences 3 (2021) : 11–20. http://dx.doi.org/10.19110/geov.2021.3.2.

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Ultramafic rocks of the Enganepe Uplift are transformed into serpentinites, magnesite-dolomite-talc and quartz-magnesite-dolomite metasomatites belonging to the beresite-listvenite formation. All apoultramafic rocks contain high chromium and nickel inherent in protolith. Chrome-spinel of the magmatic stage is represented by alumochromite, which, in the process of metamorphic and metasomatic transformation of rocks, has been replaced by secondary chrome-spinel (subferrialumochromite, ferrichromite) and chromium-bearing magnetite. The main nickel minerals are millerite and gersdorffite. In quartz-magnesite-dolomite rocks, nickel is party contained in Ni-Cr-chlorite.
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Zoheir, Basem, et Bernd Lehmann. « Listvenite–lode association at the Barramiya gold mine, Eastern Desert, Egypt ». Ore Geology Reviews 39, no 1-2 (février 2011) : 101–15. http://dx.doi.org/10.1016/j.oregeorev.2010.12.002.

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Belogub, Elena V., Irina Yu Melekestseva, Konstantin A. Novoselov, Mariya V. Zabotina, Gennady A. Tret'yakov, Victor V. Zaykov et Anatoly M. Yuminov. « Listvenite-related gold deposits of the South Urals (Russia) : A review ». Ore Geology Reviews 85 (mai 2017) : 247–70. http://dx.doi.org/10.1016/j.oregeorev.2016.11.008.

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9

Boskabadi, Arman, Iain K. Pitcairn, Matthew I. Leybourne, Damon A. H. Teagle, Matthew J. Cooper, Hossein Hadizadeh, Rasoul Nasiri Bezenjani et Reza Monazzami Bagherzadeh. « Carbonation of ophiolitic ultramafic rocks : Listvenite formation in the Late Cretaceous ophiolites of eastern Iran ». Lithos 352-353 (janvier 2020) : 105307. http://dx.doi.org/10.1016/j.lithos.2019.105307.

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Hinsken, Tim, Michael Bröcker, Harald Strauss et Florian Bulle. « Geochemical, isotopic and geochronological characterization of listvenite from the Upper Unit on Tinos, Cyclades, Greece ». Lithos 282-283 (juin 2017) : 281–97. http://dx.doi.org/10.1016/j.lithos.2017.02.019.

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Moussa, Hilmy E., Mokhles K. Azer, Moustafa A. Abou El Maaty, Ayman E. Maurice, Nagy N. Yanni, Adel I. M. Akarish, Ahmed A. Elnazer et Mustafa A. Elsagheer. « Carbonation of Neoproterozoic mantle section and formation of gold-bearing listvenite in the Northern Nubian Shield ». Lithos 406-407 (décembre 2021) : 106525. http://dx.doi.org/10.1016/j.lithos.2021.106525.

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Emam, Ashraf, et Basem Zoheir. « Au and Cr mobilization through metasomatism : Microchemical evidence from ore-bearing listvenite, South Eastern Desert of Egypt ». Journal of Geochemical Exploration 125 (février 2013) : 34–45. http://dx.doi.org/10.1016/j.gexplo.2012.11.004.

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Chetvertakov, I. V., V. A. Vanin et I. A. Demin. « Geologic Structure, Mineralogy, and Geochemistry of the Nerunda Gold Ore Field (Northern Transbaikalia) ». Russian Geology and Geophysics 62, no 10 (1 octobre 2021) : 1139–56. http://dx.doi.org/10.2113/rgg20194119.

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Abstract —We consider the geologic structure of the Nerunda gold ore field located in the Nerunda–Mama ore district in northern Transbaikalia. Gold–quartz low-sulfide formation and ore-bearing carbonate-terrigenous strata and intrusive complexes are briefly described. An ore complex of beresite–listvenite metasomatites hosting carbonate–quartz veins and vein–veinlet zones is characterized. Two stages of ore formation have been recognized. Anomalous geochemical associations and the composition of ore mineralization typical of these stages have been established. Mineralogical and geochemical studies of gold-bearing metasomatites of the Nerunda ore field were carried out. The known geochemical and mineralogical search criteria used for the assessment of the erosion zone level of gold deposits were applied to the geologic conditions of the Nerunda ore field and the Nerunda–Mama gold ore district as a whole. The emphasis was made on the express assessment of the erosion zone level at the early stage of prospecting. We draw a conclusion about the gold potential of the poorly studied ore objects at depth and give guidelines for the following geological prospecting.
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Falk, Elisabeth S., et Peter B. Kelemen. « Geochemistry and petrology of listvenite in the Samail ophiolite, Sultanate of Oman : Complete carbonation of peridotite during ophiolite emplacement ». Geochimica et Cosmochimica Acta 160 (juillet 2015) : 70–90. http://dx.doi.org/10.1016/j.gca.2015.03.014.

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15

Gahlan, Hisham A., Mokhles K. Azer, Paul D. Asimow et Khaled M. Al-Kahtany. « Formation of gold-bearing listvenite in the mantle section of the Neoproterozoic Bir Umq ophiolite, Western Arabian Shield, Saudi Arabia ». Journal of African Earth Sciences 190 (juin 2022) : 104517. http://dx.doi.org/10.1016/j.jafrearsci.2022.104517.

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Aftabi, Alijan, et Mohammad Hossien Zarrinkoub. « Petrogeochemistry of listvenite association in metaophiolites of Sahlabad region, eastern Iran : Implications for possible epigenetic Cu–Au ore exploration in metaophiolites ». Lithos 156-159 (janvier 2013) : 186–203. http://dx.doi.org/10.1016/j.lithos.2012.11.006.

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17

Halls, C., et R. Zhao. « Listvenite and related rocks : perspectives on terminology and mineralogy with reference to an occurrence at Cregganbaun, Co. Mayo, Republic of Ireland ». Mineralium Deposita 30, no 3-4 (juin 1995) : 303–13. http://dx.doi.org/10.1007/bf00196366.

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Bédard, Jean H., et Monica Escayola. « The Advocate ophiolite mantle, Baie Verte, Newfoundland : regional correlations and evidence for metasomatismGeological Survey of Canada, Earth Sciences Sector, Contribution 20090211. » Canadian Journal of Earth Sciences 47, no 3 (mars 2010) : 237–53. http://dx.doi.org/10.1139/e10-004.

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Mantle rocks of the Advocate ophiolite near Flatwater Pond (Baie Verte, Newfoundland) are dominated by harzburgite tectonites, which are extensively converted to listvenite along the Baie Verte Road fault and represent a potential gold exploration target. Most Advocate harzburgites have forsteritic olivine (Fo90.5 to Fo93) and Cr-spinels, with Cr# (= 100Cr/(Cr + Al)) between 52 and 64 and Mg# (= 100Mg/(Mg + Fe2+)) between 56 and 68. These mineral chemical signatures, together with high whole-rock MgO (46%–48%), low Al2O3 (<1%), and TiO2 (<0.003%), imply the Advocate harzburgites are refractory residues after ca. 25%–35% melting. Cr-spinel compositions of Advocate mantle rocks overlap with Cr-spinels from the mantle rocks of the Point Rousse and Betts Cove ophiolites, with Mg# higher than those of Bay of Islands or Thetford Mines mantle Cr-spinels. Although refractory in terms of major elements and mineral chemistry, Advocate harzburgites contain high La–Ce–Pr–Pb–Nd–Sm–Zr contents suggestive of pervasive metasomatism. Similar geochemical signatures occur in all ophiolitic mantle rocks from the Baie Verte Peninsula examined so far. The enrichments are not consistent with supra-subduction zone syn-melting metasomatism as observed in other Appalachian ophiolites. The apparent absence of visible metasomatic channels in most outcrops suggests that metasomatism occurred before obduction by diffuse percolation, but the nature and origin of the metasomatic agent remain speculative. The similarities of mineral and whole-rock geochemistry imply that all mantle rocks from Baie Verte ophiolites are correlative and may represent remnants of a single obducted slab.
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Zhiltsova, I. V., M. V. Ruzina, M. L. Malova, N. V. Bilan, O. A. Tereshkova et A. S. Gardysh. « Analysis of the spatial patterns in localization of gold mineralization relative to the system of deep faults in the Chortomlyk greenstone structure of the Ukrainian shield ». Journal of Geology, Geography and Geoecology 27, no 3 (8 janvier 2019) : 537–45. http://dx.doi.org/10.15421/111878.

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The results of analysisof the patterns of the spatial relationship between hydrothermal gold ore formations and the zones of metasomatites and systems of deep faults within the Chortomlyk greenstone structure of the Middle Pridniprovie megablock in the Ukrainian Shield are given. As a result of studying the localization conditions of gold mineralization, it was established that the gold-bearing mineralization is confined to tectonically fractured zones and is localized among metasomatically altered rocks. The hydrothermal series of metasomatites in the Chortomlyk greenstone structure is represented by greisens, propylites, amphibole-carbonate metasomatites and listvenite-berezites. The mineralization of Au and Mo is associated with metasomatites of the greisen type. The study of spatial relationship between the fields of metasomatites and the gold mineralization and zones of deep faults revealed that the closest relationship is expressed with systems of faults with azimuths of 0° and 270°, 17° and 287°, 77° and 347°. The results of the studies allowed us to develop a newprospecting criterion, which, in turn allows us to state that the gold mineralization within the Chortomlyk greenstone structure is spatially confined to metasomatites related to the schistosity, fracture, millonitization, and cataclase zones with high content of sulphide mineralization. These zones are localized in nodes of intersecting faults of the first order of the system 77° and 347° with discontinuous violations of high orders of azimuths of 0° and 270°, 17°and 287°. The results of the research can be used to develop a set of predictive criteria and the allocation of promising sites of hydrothermal mineralization of gold within the Chortomlyk greenstone structure of the Middle Pridniprovie megablock in the Ukrainian shield.
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Spiridonov, E. M. « LISTVENITES AND ZODITES ». International Geology Review 33, no 4 (avril 1991) : 397–407. http://dx.doi.org/10.1080/00206819109465698.

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Rampilova, M. V., G. S. Ripp, M. O. Rampilov, B. B. Damdinov, L. B. Damdinova et V. F. Posokhov. « Isotope-Geochemical Features of Apoultrabasic Metasomatites of the Sayan–Baikal Folded Area ». Russian Geology and Geophysics 62, no 9 (1 septembre 2021) : 1021–35. http://dx.doi.org/10.2113/rgg20194154.

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Abstract —The paper is concerned with a geochemical study of apoultrabasic metasomatites of the Ospa–Kitoi, Parama, and Ust’-Kelyana ophiolite massifs located in the southern folded framing of the Siberian craton. The isotope (O, C, H, Sr, and Rb) systems of dunites, serpentinites, nephrites, listvenites, and talc–carbonate rocks are studied. The isotopic composition of oxygen in olivines from dunites is characterized by δ18O = 4.6–5.5‰. The δ18O values of serpentinites (4.67–7.35‰) point to the mantle genesis of fluids and might have been inherited from ultrabasic rocks. Nephrites are slightly enriched in heavy oxygen isotope (δ18O = 6.13–9.54‰). This indicates that their fluid phase was transported from serpentinites and captured a small portion of the crustal component. The widest variations in δ18O values, from 8.12 to 17.46‰, are observed in minerals from listvenites. Carbonates from these rocks show a highly heterogeneous isotopic composition of oxygen (δ18O = 12.9–18.8‰) and carbon δ13C = –2.8 to +2.8‰). These rocks formed with the contribution of metamorphogenic fluids. According to the isotopic composition of hydrogen, the examined serpentinites are divided into two groups: with δD values specific to “magmatic water” (δD = –73.50 to –85.00‰) and those typical of meteoric fluids (δD = –151.90 to –167.20‰). The listvenites are characterized by low Rb and high Sr contents. Their 87Sr/86Sr values (0.70702–0.70971) indicate the contribution of a crustal source. The study of fluid inclusions in minerals from listvenites has shown that the rocks formed under relatively low-temperature conditions. The homogenization temperatures of fluid inclusions in quartz and magnesite from listvenites of the Ospa–Kitoi massif are 184–290 ºC and 122–182 ºC, respectively. In the Parama massif, the homogenization temperature of fluid inclusions in quartz is 130–170 ºC. The solutions that formed listvenites of the Ospa–Kitoi massif were slightly saline (TDS = 2.9–8.4 wt.% NaCl eq.), with NaCl and Na2CO3 being the main salt components.
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Melekestseva, I. Yu, V. V. Zaykov, G. A. Tret’yakov, K. A. Filippova et V. A. Kotlyarov. « Geological structure and mineralogy of the Mechnikovskoe gold deposit, thе Southern Urals ». LITOSFERA, no 1 (17 mars 2019) : 111–38. http://dx.doi.org/10.24930/1681-9004-2019-19-1-111-138.

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Subject. The article presents the results of study of Mechnikovskoe gold deposit associated with listvenites and beresites of the Miass region of the Southern Urals.Materials and methods. Materials were sampled during the field work of 2010– 2012. The chemical composition of rocks is analyzed by methods of classical chemistry (rock-forming oxides) and ICP MS (trace elements). The mineral composition is determined on an electron microscope with EDS.Results. The deposit is composed of tectonic sheets of serpentinites, carbonatized serpentinites and listvenites (sheet I), metadiabases and plagioclase metabasalts of the Irendyk Formation and beresites and volcanosedimentary rocks and metabasalts of the Karamalytash Formation (sheet II). In the central part of the deposit, the volcanic rocks are intruded by a dike of finegrained island-arc granites. Chromites of serpentinites are characterized (on average) by high Cr# (89) and low Mg# (29) values and low contents of Al2O3 (6.94 wt %) and MgO (5.5 wt %). Gold-bearing rocks include listvenites, beresites and carbonaceous shales. The major ore mineral is pyrite; accessory minerals are Au and Ag minerals, chalcopyrite, fahlores, galena, sphalerite, pyrrhotite, cubanite, vaesite, melonite, secondary copper sulfides, barite, rutile, monazite and xenotime. Gold of the deposit contains low Ag contents (3.52 wt %) and minor amount of Cu and Hg (<1 wt % in most analyses).Conclusions. The listvenites and beresites of the deposit were formed after ultramafic and mafic rocks, respectively. The discovery of gold in various rocks indicates that gold mineralization was deposited after the formation of the geological structure of the deposit. The source of gold was most likely related to a magmatic fluid.
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Vaskina, T. I., A. V. Dronov, S. A. Belchenko, V. V. Dyachenko et S. M. Sychev. « Optimization of elements of forage sorghum cultivation in the south-west of the Central region of Russia ». Agrarian science, no 9 (13 novembre 2022) : 131–36. http://dx.doi.org/10.32634/0869-8155-2022-362-9-131-136.

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Relevance. In the agro-climatic conditions of the southwestern part of the Central region of Russia, studies have been conducted aimed at improving the zonal agrotechnology of forage sorghum in order to optimize individual elements of cultivation that are relevant and timely. The main task was to assess the effectiveness of mineral fertilizers and seeding rates on yield, crop structure, nutritional value of the aboveground mass of sorghum varieties and hybrids, their energy assessment in the conditions of gray forest soils of the Bryansk region.Material and methods. The experimental work was carried out in 2015–2020 at the experimental field of Bryansk GAU. The objects of research were 3 sorghum-sudan grass hybrids: Slavyanskoe pole 15 F1, Sabantuy F1, Solaris and 5 varieties of sweet sorghum: Zernogradskij yantar, Debut, Listvenit, Sazhen, Sever. Agricultural technology of experiments —adopted in the region for silage and fodder crops. The laying of experiments, field records and observations were carried out according to the Broad Unified Classifier of the CMEA, the International Classifier of the CMEA of cultivated species of the genus Sorghum Moench and the Methodology of the state variety testing of agricultural crops.Results. The significant influence of azophoska , borophosphate and ammonium nitrate on the growth, development, yield and quality of the feed massof sorghum-sudan grass hybrids has been established. The highest yield of 14.8–15.8 t dry matter or 65–71 t ofgreen mass per 1 ha formed sorghum-sudan grass hybrids Sabantuy F1 and Solaris in the variant with N90 feeding on the main background 1 — azophoska N60P60K60. High-yielding agrocenoses of sweet sorghum Listvenit were marked—, 65–70.9 t/ha of green mass with a seeding rate of 500 thousand pieces of germinating seeds per 1 ha. The highest yield of gross energy with the harvest was provided by the Listvenit variety (54.8 GJ/ha), in the Sazhen and Sever varieties in the range of 50.1–50.7 GJ/ha. A high energy coefficient of 4.3–4.5 and an energy efficiency coefficient of 2.1 and 2.4respectively were shown by crops of Listvenitand Sever varieties.
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Ahankoub, Maryam, et Mohammad Ali Mackizadeh. « Mineralogy and geochemistry of the Dehshir listvenites, central Iran ». Neues Jahrbuch für Mineralogie - Abhandlungen Journal of Mineralogy and Geochemistry 196, no 1 (1 juin 2019) : 1–18. http://dx.doi.org/10.1127/njma/2019/0091.

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Plissart, G., O. Femenias, M. Maruntiu, H. Diot et D. Demaiffe. « MINERALOGY AND GEOTHERMOMETRY OF GABBRO-DERIVED LISTVENITES IN THE TISOVITA-IUTI OPHIOLITE, SOUTHWESTERN ROMANIA ». Canadian Mineralogist 47, no 1 (1 février 2009) : 81–105. http://dx.doi.org/10.3749/canmin.47.1.81.

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Menzel, Manuel D., Carlos J. Garrido, Vicente López Sánchez-Vizcaíno, Claudio Marchesi, Károly Hidas, Monica P. Escayola et Antonio Delgado Huertas. « Carbonation of mantle peridotite by CO2-rich fluids : the formation of listvenites in the Advocate ophiolite complex (Newfoundland, Canada) ». Lithos 323 (décembre 2018) : 238–61. http://dx.doi.org/10.1016/j.lithos.2018.06.001.

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Kovtunova, Natalia, Vladimir Kovtunov, Aleksey Popov, Aleksandr Volodin, Elena Shishova et Aleksandr Romanyukin. « Inheritance of the main quantitative traits in sweet sorghum hybrids F1 ». E3S Web of Conferences 175 (2020) : 01012. http://dx.doi.org/10.1051/e3sconf/202017501012.

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Sweet sorghum hybrids F1 in productivity can surpass the parental forms on 50-60%. Thus the breeding process is aimed to develop first generation hybrids with a strong potential of productivity and quality of green mass and silage. The purpose of the work is to study heritability and heterosis of the quantitative traits of sweet sorghum hybrids F1 obtained on a sterile basis. The study was conducted in 2013-2015 on the lines with cytoplasmic male sterility (‘A-63’, ‘Knyazhna’, ‘APV-1115), the varieties (‘Listvenit’, ‘Severnoe 44’, ‘Zernogradskoe 454’, ‘Stavropolskoe 36’, ‘Galiya’ and ‘Larets’) and the hybrids. The inheritance of green mass productivity and absolutely dry matter, the length of a vegetation period, plant height and leaf formation (foliage), protein content in dry matter of the hybrids occurred according to the type of dominance and overdominance. It has been determined that while choosing the parental forms for hybridization it’s essential to select the forms with differences in the vegetation period of 4-6 days to avoid the dominance of late maturity. The height pollinator increase results in the hybrid height increase and large heterosis. It’s necessary to select the parental forms with maximum foliage to improve leaf formation in the hybrids.
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Gahlan, Hisham A., Mokhles K. Azer, Paul D. Asimow et Khaled M. Al-Kahtany. « Petrogenesis of gold-bearing listvenites from the carbonatized mantle section of the Neoproterozoic Ess ophiolite, Western Arabian Shield, Saudi Arabia ». Lithos 372-373 (novembre 2020) : 105679. http://dx.doi.org/10.1016/j.lithos.2020.105679.

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Akbulut, Mehmet, Özkan P??şk??n et Al? ? İhsan Karay??????t. « The genesis of the carbonatized and silicified ultramafics known as listvenites : a case study from the Mihalıççık region (Eskişehir), NW Turkey ». Geological Journal 41, no 5 (2006) : 557–80. http://dx.doi.org/10.1002/gj.1058.

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Tzamos, Evangelos, Micol Bussolesi, Giovanni Grieco, Pietro Marescotti, Laura Crispini, Andreas Kasinos, Niccolò Storni, Konstantinos Simeonidis et Anastasios Zouboulis. « Mineralogy and Geochemistry of Ultramafic Rocks from Rachoni Magnesite Mine, Gerakini (Chalkidiki, Northern Greece) ». Minerals 10, no 11 (22 octobre 2020) : 934. http://dx.doi.org/10.3390/min10110934.

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The importance of magnesite for the EU economy and industry is very high, making the understanding of their genesis for the exploration for new deposits a priority for the raw materials scientific community. In this direction, the study of the magnesite-hosting ultramafic rocks can be proved very useful. For the present study, ultramafic rock samples were collected from the magnesite ore-hosting ophiolite of the Gerakini mining area (Chalkidiki, Greece) to investigate the consecutive alteration events of the rocks which led to the metallogenesis of the significant magnesite ores of the area. All samples were subjected to a series of analytical methods for the determination of their mineralogical and geochemical characteristics: optical microscopy, XRD, SEM, EMPA, ICP–MS/OES and CIPW normalization. The results of these analyses revealed that the ultramafic rocks of the area have not only all been subjected to serpentinization, but these rocks have also undergone carbonation, silification and clay alteration. The latter events are attributed to the circulation of CO2-rich fluids responsible for the formation of the magnesite ores and locally, the further alteration of the serpentinites into listvenites. The current mineralogy of these rocks was found to be linked to one or more alteration event that took place, thus a significant contribution to the metallo- and petrogenetic history of the Gerakini ophiolite has been made. Furthermore, for the first time in literature, Fe inclusions in olivines from Greece were reported.
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HASSAN, Musab Awad Ahmed, et Aleksandr Evgen’yevich KOTEL’NIKOV. « The geological and structural controls of gold mineralization in Qala en Nahal-Um Sagata region, South Gedarif, Sudan ». NEWS of the Ural State Mining University 59, no 3 (15 septembre 2020) : 19–26. http://dx.doi.org/10.21440/2307-2091-2020-3-19-26.

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Relevance and purpose of the work. The study area is located in Gedarif state in Sudan. The ongoing work is aimed at solving fundamental problems of the geological structure of the Qala En Nahal-Um Saqata Ophiolitic Complex and applied tasks of mineral exploration. Detailed studies are being conducted for the first time in this area. The purpose of the investigation is to study the geological and structural features of the region, as well as to obtain information about the localization of gold mineralization. Methods of research. Within the study area, a geological mapping of the ophiolitic complex was carried out. It’s included an analysis of structural elements for investigation of the structural evolution and the phases of deformation. Chemical analysis of the mineralized quartz veins to determine the gold was carried out by Atomic Absorption Spectrometry (AAS) technique at the ALS Laboratory in Saudi Arabia. Results of the work. The investigation of the structural evolution revealed at least three phases of deformation. The gold mineralization occurs in auriferous quartz veins, which are hosted in metavocano-sedimentary, sheared synorogenic granites and listvenites. The auriferous quartz veins are structurally controlled by dominantly NE main shear directions. Conclusions. The gold mineralization in the area can be classified shear zone related mineralization, which is formed during the final event accomplished by crustal cooling, and formation of auriferous quartz vein along shear zones. Gold concentration were recorded in both quartz veins and associates alteration rocks. The area is promising for the presence of a gold deposit.
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Alabushev, A. V. « The achievements in the sorghum varieties and hybrids' breeding in the ARC “Donskoy” ». Grain Economy of Russia, no 2 (16 juin 2020) : 44–48. http://dx.doi.org/10.31367/2079-8725-2020-68-2-44-48.

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Sorghum is one of the most important crops in all arid tropical and subtropical regions of Africa, Asia, and Central America. In the Russian Federation, the sowing area of sorghum varied from 8.7 to 228.6 thousand ha throughout about 20 years (1999–2018). The main share (93–98%) of the sowing area of sorghum in Russia is located in the Pre-Volga region and the Southern Federal District. The Rostov Region as a part of the Southern Federal District accounts for up to 46–69% of sorghum crops (Kovtunov, 2018). The most effective way to increase productivity and product quality is to create new varieties adapted to the soil and climatic conditions of cultivation and introduce them into agricultural production. The FSBSI “Agricultural Research Center “Donskoy” developed the white-kernelled sorghum varieties “Velikan”, “Zernogradskoye 88” and “Ataman” with 5.41–5.85 t/ha of productivity not only for fodder, but also for food (starch, alcohol). The sweet sorghum varieties “Listvenit”, “Yuzhnoye” and “Feniks” with green mass productivity of 38–46 t/ha are intended for use on green fodder and silage and are characterized by intensive initial growth, lodging resistance, drought resistance, resistance to dust smut, bacteriosis and to cereal aphids. The Sudan grass varieties “Anastasiya”, “Alisa” and “Gratsiaya” developed in the Agricultural Research Center “Donskoy” are characterized by the intensive initial growth and regrowth. They are middle-ripening, drought tolerant, highly productive with 41–44 t/ha of green mass and 8.3–8.6 t/ha of dry matter. There have been developed and are being tested the promising sorghum-Sudan hybrids with 62–77 t/ha of green mass and 11.4–16.6 t/ha of dry matter obtained in mowing the aftermath.
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Šimurková, Mária. « Metasomatic column with the apobasite listvenites end-member from the Slovinky-Gelnica ore field (Gemeric Superunit, Western Carpathians) and comparison to their type localities from Ural ». Geology, Geophysics & ; Environment 41, no 1 (2015) : 132. http://dx.doi.org/10.7494/geol.2015.41.1.132.

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DVORNIK, Gennadiy Petrovich. « Types of metasomatic rocks : temperature conditions, buildups, features of composition, minerageny ». NEWS of the Ural State Mining University 1, no 1 (23 mars 2020) : 63–72. http://dx.doi.org/10.21440/2307-2091-2020-1-63-72.

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The relevance of the work is due to the importance of metasomatic rocks associated many ore and non-metallic mineral resources. Purpose of the work: study of temperature conditions of formation, the characteristics of the chemical and mineral composition, the mineralogy of metasomatites. Results. The extended classification of the main types of metasomatic rocks (alkaline, basic, acidic) formed in the early alkaline and acid stages of the hydrothermal process is given. Temperature conditions of formation, features of chemical and mineral composition and metasomatite mineralogeny are considered. Alkaline metasomatites are subdivided into potassium (pyroxene phenites, microclinites, biotite-orthoclase metasomatites, gumbaites) and sodium (nepheline-pyroxene phenites, albites, sodic alterations). Deposits of tungsten, molybdenum, gold and uranium are associated with potassium metasomatites (gumbaites), and deposits of beryllium, lithium, tantalum, and niobium are associated with sodium metasomatites (albite). The main metasomatic rocks (basificates) include calcium and iron-magnesian metasomatites (calcareous and magnesian skarns, diopside-lapis lazuli metasomatites, rhodingites, kamaforites, carbonatites, apocarbonate calcites, dolomite-ankerite, magnesite and sideroplesite metasomatites). The formation of deposits of iron, boron, and phlogopite is associated with skarn; deposits of rare-earth elements, tantalum, niobium, and apatite are associated with carbonatites. Acid metasomatites are subdivided into aluminous and siliceous. Aluminous metasomatites include propylites, chloritolites, microcline-sericite and tourmaline-sericite metasomatites, secondary quartzites, argillizated rocks. Alumina deposits (kaolins, bentonites) are associated with secondary quartzites. Siliceous metasomatites include the largest number of species: uralite metasomatites, greisens, listvenites and berezites, chlorite-sericite-quartz and sericite-quartz metasomatites, charoitites, serpentinites, nephrites, anthophyllite metasomatites, carbonate-talc metasomatites and talcites, magnetite quartzites, jaspers, jasperoids. There is a group of metasomatites among them consisting of quartz in association with hydrous alumosilicates (muscovite, topaz, and chlorite). The other group includes low-alumina metasomatites, the mineral composition of which is dominated by hydrous calcium and magnesian silicates (charoite, serpentine, antophyllite, tremolite, talc). The third group is represented by metasomatites of quartz composition (magnetite quartzites, jaspers, jasperoids). The formation of deposits of iron, tin, tungsten, molybdenum, gold, polymetals, nonmetallic raw materials (asbestos, talc, charoite, nephrite, jasper) is associated with siliceous metasomatites. Conclusions. According to the formation temperature, high-temperature (above 500o С), medium-temperature (500–300о С) and low-temperature (below 300o С) metasomatic rocks are distinguished. The average compositions of alkaline metasomatites are characterized by high concentrations of potassium or sodium oxides, the predominance of feldspars (orthoclase, microcline, albite) in association with pyroxenes, carbonates. The main metasomatites are distinguished by high contents of calcium, magnesium and iron oxides at low silica concentrations prevailing in the mineral composition of silicates (pyroxenes and garnets) or carbonates (calcite, dolomite, magnesite, breunnerite). The composition of acid metasomatites is characterized by high concentrations of alumina or silica, the predominance of hydrous aluminosilicates, silicates and quartz.
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Lagabrielle, Yves, Riccardo Asti, Serge Fourcade, Benjamin Corre, Marc Poujol, Jessica Uzel, Pierre Labaume et al. « Mantle exhumation at magma-poor passive continental margins. Part I. 3D architecture and metasomatic evolution of a fossil exhumed mantle domain (Urdach lherzolite, north-western Pyrenees, France) ». BSGF - Earth Sciences Bulletin 190 (2019) : 8. http://dx.doi.org/10.1051/bsgf/2019007.

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In two companion papers, we report the detailed geological and mineralogical study of two emblematic serpentinized ultramafic bodies of the western North Pyrenean Zone (NPZ), the Urdach massif (this paper) and the Saraillé massif (paper 2). The peridotites have been exhumed to lower crustal levels during the Cretaceous rifting period in the future NPZ. They are associated with Mesozoic pre-rift metamorphic sediments and small units of thinned Paleozoic basement that were deformed during the mantle exhumation event. Based on detailed geological cross-sections and microprobe mineralogical analyses, we describe the lithology of the two major extensional fault zones that accommodated: (i) the progressive exhumation of the lherzolites along the Cretaceous basin axis; (ii) the lateral extraction of the continental crust beneath the rift shoulders and; (iii) the decoupling of the pre-rift cover along the Upper Triassic (Keuper) evaporites and clays, allowing its gliding and conservation in the basin center. These two fault zones are the (lower) crust-mantle detachment and the (upper) cover décollement located respectively at the crust-mantle boundary and at the base of the detached pre-rift cover. The Urdach peridotites were exposed to the seafloor during the Late Albian and underwent local pervasive carbonation and crystallization of calcite in a network of orthogonal veins (ophicalcites). The carbonated serpentinized peridotites were partly covered by debris-flows carrying fragments of both the ultramafics and Paleozoic crustal rocks now forming the polymictic Urdach breccia. The mantle rocks are involved in a Pyrenean overturned fold together with thin units of crustal mylonites. Continent-derived and mantle-derived fluids that circulated along the Urdach crust-mantle detachment led to the crystallization of abundant metasomatic rocks containing quartz, calcite, Cr-rich chlorites, Cr-rich white micas and pyrite. Two samples of metasomatized material from the crust-mantle detachment yielded in situ zircon U/Pb ages of 112.9 ± 1.6 Ma and 109.4 ± 1.2 Ma, thus confirming the Late Albian age of the metasomatic event. The cover décollement is a 30-m thick fault zone which also includes metasomatic rocks of greenschist facies, such as serpentine-calcite association and listvenites, indicating large-scale fluid-rock interactions implying both ultramafic and continental material. The lowermost pre-rift cover is generally missing along the cover décollement due to tectonic disruption during mantle exhumation and continental crust elision. Locally, metasomatized and strongly tectonized Triassic remnants are found as witnesses of the sole at the base of the detached pre-rift cover. We also report the discovery of a spherulitic alkaline lava flow emplaced over the exhumed mantle. These data collectively allow to propose a reconstruction of the architecture and fluid-rock interaction history of the distal domain of the upper Cretaceous northern Iberia margin now inverted in the NPZ.
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« Listvenite as gemstone : the Antina Čuka occurrence (Eastern Serbia) ». Acta Montanistica Slovaca, no 27 (20 février 2023) : 1007–16. http://dx.doi.org/10.46544/ams.v27i4.14.

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Antina Čuka listvenite originated by hydrothermal alteration of small ophiolite mass caused by Paleogene magmatic activity. Mineralogical and petrological examination of the listvenite revealed serpentine-rich, silica-rich, and carbonate-rich varieties of the listvenite. Typical minerals are serpentine (group), carbonates (calcite, dolomite, and magnesite), pyrite, gersdorffite, Cr-spinel, barite, limonite, and native Ag. Gemological analysis revealed all serpentine varieties from Antina Čuka (serpentine-rich listvenite, serpentine-rich listvenite with magnetite and fresh serpentinite) have values of both refractive index and specific gravity in the range for serpentine group minerals. A Refractive index value of 1.54 for silica-rich variety confirms the presence of quartz. The results of lapidary processing have proven that both listvenite from Antina Čuka and serpentinite host rock are attractive gemstones. The adequate types of processing of Antina Čuka listvenite are plain cut (different-shaped cabochons) and glyptography/carving.
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Austrheim, Håkon, Fernando Corfu et Christian J. Renggli. « From peridotite to fuchsite bearing quartzite via carbonation and weathering : with implications for the Pb budget of continental crust ». Contributions to Mineralogy and Petrology 176, no 11 (22 octobre 2021). http://dx.doi.org/10.1007/s00410-021-01851-z.

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AbstractExtensive carbonation of peridotite results in listvenite, a rock composed of magnesite and quartz. At Gråberget, Røros, SE-Norway, a variably serpentinized peridotite body, surrounded by the Røros schists, a former abyssal sediment displays all stages of transformation of peridotite to quartzite. In this paper we record the sequence of steps in this process by combining the observation of mineral assemblages, textural relationships and geochemistry, and variations in Pb isotopic compositions. Initial serpentinization, a stage that also involved an enrichment in fluid-mobile elements (Pb, Sb and As), was followed by carbonation through CO2 fluids that formed soapstone, and eventually listvenite. The listvenite grades by decreasing amounts of carbonates into fuchsite bearing quartzite. The carbonates dissolved during supergene alteration and formed pores coated with oxides of Fe, Mn and Ni resulting in a brown rock color. The quartzite displays porous stylolites enriched in Pb, As and Sb and fuchsite with porous chromite grains as the only relicts of the original mineralogy in the peridotite. The dissolution of the carbonate occurred at oxidizing conditions at temperatures below 150 °C, where the solubility of magnesite is higher than that of quartz. Formation of quartzite from peridotite is supported by low REE contents and lack of zircons in the two rock types. The transformation involved enrichment of Pb, coupled with the elimination of Mg and enrichment of Si. This chemical fractionation and selective transfer of elements to the continents is an important mechanism and needs to be taken into account in models of continental evolution.
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Turan, Tahir Inan, et Caner Diker. « Remote Sensing of Listvenite Rock for Kaymaz Gold Deposit, Eskişehir-Turkey ». SSRN Electronic Journal, 2022. http://dx.doi.org/10.2139/ssrn.4072904.

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Turan, Tahir İnan, et Caner Diker. « Remote sensing of Listvenite rock for Kaymaz Gold Deposit, Eskişehir-TÜRKİYE ». Journal of Geochemical Exploration, octobre 2022, 107110. http://dx.doi.org/10.1016/j.gexplo.2022.107110.

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Beinlich, A., O. Plümper, E. Boter, I. A. Müller, F. Kourim, M. Ziegler, Y. Harigane, R. Lafay et P. B. Kelemen. « Ultramafic Rock Carbonation : Constraints From Listvenite Core BT1B, Oman Drilling Project ». Journal of Geophysical Research : Solid Earth 125, no 6 (juin 2020). http://dx.doi.org/10.1029/2019jb019060.

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VURAL, Alaaddin. « Heavy Metal Pollution from Listvenitization : In Case of Alakeçi Bayramiç-Çanakkale/West Türkiye) ». Turkish Journal of Analytical Chemistry, 21 novembre 2022. http://dx.doi.org/10.51435/turkjac.1190831.

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This study aimed to investigate the risk of element/heavy metal pollution caused by listvenitization. In this context, the heavy metal pollution risk of listvenite-derived soils in the region where listvenitized ultrabasic rocks are present as a result of hydrothermal alterations in the vicinity of Alakeçi (Bayramiç Çanakkale/Western Türkiye) was investigated with pollution index, geoaccumulation index and integrated pollution risk parameters. For this purpose, Cu, Zn, Pb element concentrations of 350 soil samples collected from the field were determined, and Pollution Index (PI) and Geo-accumulation Index (Igeo) parameters for each element and Integrated Pollution Index (IPI) parameters for each sampling point were calculated. In addition, distribution maps of PI, Igeo and IPI parameters were plotted. When the site is considered in terms of IPI parameter, it has been determined that the site has medium and high pollution risk. When the field is considered in terms of PI and Igeo parameters, a remarkable level of pollution has been detected in the field, especially by Ni, Co and As elements. When the distribution maps of the PI, Igeo and IPI parameters are examined, it has been determined that the pollution risk is higher than the other areas, especially in the areas where hydrothermal alteration is intense and in the tectonic line areas. Although listvenitizations and listvenite zones are important target areas especially for epithermal gold mineralizations, this study has shown that listvenitization areas are also areas at risk of heavy metal pollution. Therefore, listvenitization zones are areas that should be investigated in terms of heavy metal pollution risk as well as epithermal gold mineralization potentials.
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Buriánek, David, et Jiří Svatuška. « Těžké minerály rozsypových ložisek zlata vázaných na khantaishirský ofiolitový komplex poblíž měst Altaj a Khaliun (jihozápadní Mongolsko) ». Geologické výzkumy na Moravě a ve Slezsku 27, no 1-2 (30 novembre 2020). http://dx.doi.org/10.5817/gvms2020-13215.

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Detailed morphological and chemical studies of heavy minerals from two localities fluvial sediments in the area of the khantaishir ophiolitic complex near the towns Altai and Khaliun (Southwestern Mongolia) allowed the interpretation possible source region for the gold. The heavy mineral spectrum from the sediments near the Altai town is dominated by magnetite (32 %), chromite (27 %), epidote (11 %), apatite (6 %), and clinopyroxene (5 %). We assume that these minerals come from the ultrabasic and basic igneous rocks in the Neoproterozoic khantaishir ophiolitic complex. The relatively undeformed and three-dimensional shape of gold particles indicating short distance their transport. Rare is native gold enclosed in dolomite or quartz, which indicates that potential gold sources are listvenite. The heavy mineral spectrum from the fluvial sediments in the small creek near the Khaliun town is different. The studied sample includes magnetite (31 %), amphibole (19 %), zircon (18 %), pyrite (13 %), apatite (5 %), epidote (4 %), titanite (4 %), clinopyroxene (2 %), monazite (1 %), ilmenite (1 %), garnet (1 %), and barite (0.1 %). Large variations in the mineral composition heavy mineral spectrum indicate a wide source area which includes basic to intermediate igneous rocks Cambrian-Ordovician Ikh-Mongol Arc System and medium-grade metamorphic rocks (metapelite). The subspherical rounded shape of the gold particles indicates fluvial transport. In the case of small and geologically simple drainage area as creek near the Altai town represents heavy minerals a good tool for determination of the origin of placer gold. There is a contrast between the heavy mineral spectrum from the localities near the Altai and Khaliun towns. The shape of gold particles as well as a simple heavy mineral spectrum from sediments near the Altai indicates short transport from the limited draining area (approximately 6 km2). Gold probably originating from the ultramafic rocks (listvenite), according to associated dolomite and simple spectrum of heavy minerals. Whereas the origin of gold from the placer deposits near Khalinun remains unclear and most probably could originate from the hydrothermal veins in intermediate or basic igneous rocks (presence of barite associated with abundant pyrite).
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Ji, Chen, Kai-Jun Zhang et Li-Long Yan. « Hydrothermal metasomatism and solid-phase transfer in petrogenesis of listvenite : the Meso-Tethyan ophiolite, central Tibet, China ». Contributions to Mineralogy and Petrology 178, no 1 (26 décembre 2022). http://dx.doi.org/10.1007/s00410-022-01988-5.

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Pirouei, Mohammad, Kamal Kolo et Stavros P. Kalaitzidis. « Chromium-rich muscovite mineralization in Zagros ophiolites in Iraqi Kurdistan : a study on fuchsite paragenetic association with listvenite types ». Arabian Journal of Geosciences 13, no 17 (27 août 2020). http://dx.doi.org/10.1007/s12517-020-05887-6.

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Kelemen, Peter B., Juan Carlos de Obeso, James A. Leong, Marguerite Godard, Keishi Okazaki, Alissa J. Kotowski, Craig E. Manning et al. « Listvenite Formation During Mass Transfer into the Leading Edge of the Mantle Wedge : Initial Results from Oman Drilling Project Hole BT1B ». Journal of Geophysical Research : Solid Earth 127, no 2 (28 janvier 2022). http://dx.doi.org/10.1029/2021jb022352.

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Godard, M., E. J. Carter, T. Decrausaz, R. Lafay, E. Bennett, F. Kourim, J. ‐C Obeso et al. « Geochemical Profiles Across the Listvenite‐Metamorphic Transition in the Basal Megathrust of the Semail Ophiolite : Results From Drilling at OmanDP Hole BT1B ». Journal of Geophysical Research : Solid Earth 126, no 12 (décembre 2021). http://dx.doi.org/10.1029/2021jb022733.

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Ferenc, Š., P. Uher, J. Spišiak et V. Šimonová. « Chromium- and nickel-rich micas and associated minerals in listvenite from the Muránska Zdychava, Slovakia : products of hydrothermal metasomatic transformation of ultrabasic rock ». Journal of Geosciences, 17 octobre 2016, 239–54. http://dx.doi.org/10.3190/jgeosci.217.

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Okazaki, Keishi, Katsuyoshi Michibayashi, Kohei Hatakeyama, Natsue Abe, Kevin T. M. Johnson et Peter B. Kelemen. « Major Mineral Fraction and Physical Properties of Carbonated Peridotite (Listvenite) From ICDP Oman Drilling Project Hole BT1B Inferred From X‐Ray CT Core Images ». Journal of Geophysical Research : Solid Earth 126, no 12 (27 novembre 2021). http://dx.doi.org/10.1029/2021jb022719.

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Богуш, И. А., Г. В. Рябов, И. И. Сендецкий et В. И. Черкашин. « Prospects for the ore content of listvenites in the North Caucasus (the Elbrus region) ». Геология и геофизика Юга России, no 3 (21 septembre 2022). http://dx.doi.org/10.46698/vnc.2022.77.74.006.

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Актуальность работы. Альпинотипные ультрабазиты Северного Кавказа отнесены к региональным продуцентам благородных металлов (Au, Pt, Pd, Os. Ir, Ru, Rh). Продукты разрушения и переработки ультрабазитов (черные сланцы, коры выветривания, базальные горизонты, россыпи) часто содержат аномальные субпромышленные концентрации этих металлов. К дериватам ультрабазитов отнесены приконтактовые метасоматиты, представленные лиственитами, талькитами, тальк-карбонатными амфибол-хлорит-карбонатными, кварц-карбонатными, анхикварцевыми и анхикарбонатными породами. Ультрабазитовые дериваты аномально обогащены благородными металлами (Au, Pt, Pd), в ряде случаев представляющими промышленный интерес. Одним из таких ярких представителей дериватов являются листвениты, которые до настоящего времени практически детально не изучены на предмет содержания благородных металлов. Цель работы. В основу работ положены исследования лиственитов в рамках изучения металлогении благородных металлов Северного Кавказа с целью определения их пространственной и генетической связи с ультрабазитами, которые локализуются в зоне контакта соприкасающихся рудных полей крупного медноколчеданного Худесского и золоторудного Чучкурского месторождений. Методы исследования. Проведен исторический обзор литературных данных на предмет генетического родства и тесной связи лиственитов с ультрабазитами Северного Кавказа, исходно содержащими благородные металлы (Au, Pt, Pd). Результаты исследования базируются на основе изучения существующего каменного материала на предмет определения их состава, геохимическим особенностям и их потенциальной рудоносности. Результаты работ. Изучены ореольные листвениты, как наиболее близкие дериваты переработки ультрабазитов, содержащие золото, но совершенно не исследованные на металлы платиновой группы. Непосредственно с 1985 года исследуется поле чучкурских лиственитов Северного Приэльбрусья, примыкающее к крупному эндогенному Чучкурскому месторождению благородных металлов. Выделены геологические, минеральные и геохимические особенности лиственитов. Особое внимание обращено на проявления золота в лиственитах, геохимию и минералогию в сравнении с золотоносными телами андезито-дацитовых пермских вулканитов Чучкурского месторождения. Делается вывод о перспективах комплекса благородных металлов в лиственитах, аналогичного металлам Чучкурского месторождения. Впервые для Северного Кавказа рассматривается благороднометалльная (Au, Pt, Pd)рудоносность лиственитов. Relevance. Alpine-type ultrabasites of the North Caucasus are classified as regional producers of noble metals (Au, Pt, Pd, Os, Ir, Ru, Rh). Products of destruction and processing of ultrabasites (black shales, weathering crusts, basal levels, placers) often contain anomalous sub-commercial concentrations of these metals. Near-contact metasomatites, represented by listvenites, talcites, talc-carbonate amphibole-chlorite-carbonate, quartz-carbonate, anchiquartz and anchicarbonate rocks, are classified as ultrabasite derivatives. Ultrabasite derivatives are anomalously enriched in noble metals (Au, Pt, Pd), which in some cases are of industrial interest. One of such brightest representatives of derivatives are listvenites, which practically have not been studied in detail for the content of noble metals by now. Aim. The work is based on the study of listvenites in the framework of the study of the metallogeny of the noble metals of the North Caucasus in order to determine their spatial and genetic relationship with ultrabasites, which are localized in the contact zone of ore fields of the large copper-pyrite Khudessky and gold-bearing Chuchkursky deposits. Methods.A historical review of the literature data on the genetic relationship and close relationship of listvenites with the ultrabasites of the North Caucasus, which initially contain noble metals (Au, Pt, Pd), has been carried out. The results of the research are based on the study of existing rock material in order to determine their composition, geochemical features and their potential ore content. Results. Aureole listvenites have been studied as the closest derivatives of ultrabasite processing, containing gold, but they are completely unexplored for platinum group metals. The field of Chuchkursky listvenites of the Northern Elbrus region, adjacent to the large endogenous Chuchkursky deposit of noble metals, has been explored since 1985. Geological, mineral and geochemical features of listvenites are distinguished. Particular attention is paid to the gold prospect in listvenites, geochemistry and mineralogy in comparison with the gold-bearing bodies of andesite-dacitic Permian volcanic rocks of the Chuchkursky deposit. A conclusion is made about the prospects of a complex of noble metals in listvenites, similar to the metals of the Chuchkursky deposit. For the first time for the North Caucasus, the ore content of listvenites with noble metals is considered.
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Menzel, Manuel D., Janos L. Urai, Estibalitz Ukar, Greg Hirth, Alexander Schwedt, András Kovács, Lidia Kibkalo et Peter B. Kelemen. « Ductile deformation during carbonation of serpentinized peridotite ». Nature Communications 13, no 1 (16 juin 2022). http://dx.doi.org/10.1038/s41467-022-31049-1.

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AbstractCarbonated serpentinites (listvenites) in the Samail Ophiolite, Oman, record mineralization of 1–2 Gt of CO2, but the mechanisms providing permeability for continued reactive fluid flow are unclear. Based on samples of the Oman Drilling Project, here we show that listvenites with a penetrative foliation have abundant microstructures indicating that the carbonation reaction occurred during deformation. Folded magnesite veins mark the onset of carbonation, followed by deformation during carbonate growth. Undeformed magnesite and quartz overgrowths indicate that deformation stopped before the reaction was completed. We propose deformation by dilatant granular flow and dissolution-precipitation assisted the reaction, while deformation in turn was localized in the weak reacting mass. Lithostatic pore pressures promoted this process, creating dilatant porosity for CO2 transport and solid volume increase. This feedback mechanism may be common in serpentinite-bearing fault zones and the mantle wedge overlying subduction zones, allowing massive carbonation of mantle rocks.
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