In the Proterozoic Evje-Iveland pegmatite field of southern Norway, five pegmatites have been found to exhibit features of large-scale hydraulic brecciation that have been previously overlooked or misinterpreted. We provide the first detailed description and characterization of these breccias from a study of the Landsverk 1 pegmatite, with additional insights from Gudmundsgruve, Haugen 1 and Haugen 2 and Storsynken. This is based on studies of the breccia cement, specifically oxygen isotope, trace element and cathodoluminescence data for quartz, Ar-40/Ar-39 dating of K-feldspar and trace elements in fluorite. The clast-supported breccias in the Landsverk 1 pegmatite consist of millimetre- to meter-sized fragments of pegmatite (similar to 95 vol%) and wall rocks (similar to 5 vol%) incorporated due to sidewall collapse. Fluid flow through the breccias led to infilling and replacement mostly by milky white quartz and epidote, but also left a high percentage of open space, including cavities up to 1.5 m in size. The process responsible for breccia formation was fluid-assisted hydraulic fracturing caused by a single pulse of stress at pressures between 50 and 250 MPa. Ar-40/Ar-39 dating of K-feldspar crystals from cavities in the cement yielded an early Triassic age of 246.1 +/- 0.9 Ma, which is approximately 660 Ma younger than the emplacement of the pegmatite-forming melts. This indicates that, contrary to previous interpretations, brecciation was not part of the magmatic evolution of the pegmatite. From the delta O-18 values of breccia cement quartz (-8.38 +/- 0.28 parts per thousand), fluids involved in the initial stages of cementation had a temperature of 549 +/- 23 degrees C and were meteoric in origin. So far, five megabreccias have been identified within a 12 km long, NNW-SSE-striking corridor in the Evje-Iveland area, indicating that the brecciation event is a regional phenomenon. The orientation and timing indicate formation under E-W to ENE-WSW extensional stress, with dolerite dykes emplaced along associated faults during the South-Scandinavian Permian-Triassic rift (phase 1).

We show that supercritical fluids or melts are verifiable by critical high-temperature and high-pressure minerals like diamond, lonsdaleite, and others in crustal rocks as foreign minerals. In combination with the pseudo-binary solvus curves (temperature versus water content of silicate melts) with the Lorentzian distribution of some ore-forming elements, which are untypical for hydrothermal forming processes, we have solid proof for the interaction of mantle fluids and crustal rocks (granites). In this contribution, we restrict ourselves to a small number of critical observations, in particular on cassiterite polytypes.

In zircon from the kimberlite pipe Koffiefontein Mine, Free State Province, South Africa, we describe in short two types of diamond: Besides this singleband diamond, there are also two-phase diamond particles present with a Raman doublet at 1324.5 and 1330.6 cm -1 .The applicability of the Ti-in zircon thermometer in the described case is doubtful.

Besides a pseudo-secondary solvus curve (water vs. temperature), we show in this contribution an unusual enrichment of sulfate in melt inclusion in quartz from an aplite vein in the Lusatian granodiorite.Sulfate is Lorentzian distributed.Together with the solvus curve and this type of element distribution, we interpret these as a result of the interaction of supercritical fluids coming from mantle deeps with more crustal rocks.

The Vienna Basin is located in the transition zone between the Alps and the Carpathians. Its tectonostratigraphic structure is complex, and includes from base to top crystalline basement, autochthonous Mesozoic sediments, Cenozoic foreland basin deposits, the Alpine nappe system and a thick Neogene basin fill. The Vienna Basin area hosts one of the major hydrocarbon provinces of Central Europe, but also a significant geothermal potential. The petroleum system is mainly based on the Upper Jurassic Mikulov source rock in the authochthonous succession, which became mature during nappe stacking and Neogene basin subsidence. Migration along faults and via basement highs filled oil and gas reservoirs in all tectonostratigraphic units. Despite a 100-year-long exploration history, new discoveries are still being made. Two geothermal systems are known in the Vienna Basin. One system is based on hot fluids ascending along the major faults in the southern part of the basin and has been used for balenological purposes since Roman times. The other is based on deeply buried, highly permeable carbonate rocks in the Alpine wedge (e.g. Hauptdolomite Formation) and clastic reservoirs in the Neogene basin fill. Current projects aim to supply the city of Vienna with geothermal heat from Lower Miocene fluvial conglomerates.

From these curves (Figures 1a and1b), we see that at the critical point (solvus crest), a high concentration of H 2 O, B 2 O 3 , and F are present: about 27.5, 4.2, and 9.0%, respectively.The data are from published and unpublished data from Veksler and Thomas (2002) [1][2][3][4].From unpublished hydrothermal diamond anvil cell (HDAC) experiments performed in 2002 together with Ilya Veksler and Christian Schmidt, we know that using synthetic pegmatite melts similar to the Ehrenfriedersdorf pegmatite with about 50 [% (vol/vol)] water in the temperature range from 840 down to 300°C multistage liquid-liquid immiscibility processes happens.Each main phase ever formed tends to liquid immiscibility.Such compartments are

Aspects in Mining & Mineral Science Supercritical Fluids Conserved as Fluid and Melt Inclusion in Quartz from the Sheba-Gold Mine, Barberton, South Africa Rainer Thomas1*, Paul Davidson2, Adolf Rericha3 and Ulrich Recknagel4 1Im Waldwinkel 8 D-14662 Friesack, Germany 2Codes, Centre for Ore Deposits and Earth Sciences, University of Tasmania, Hobart 7001, Australia 3Alemannenstraße 4a, D-144612 Falkensee, Germany 4Böhmerwaldstraße 22, D-86529 Schrobenhausen, Germany *Corresponding author: Rainer Thomas, Im Waldwinkel 8 D-14662 Friesack, Germany Submission: February 01, 2023;Published: February 14, 2023 DOI: 10.31031/AMMS.2023.10.000750 ISSN 2578-0255Volume10 Issue5

MethodAll microscopic and Raman spectrometric studies are performed with a petrographic polarization microscope with a rotating stage coupled with the RamMics R532 Raman spectrometer working in the spectral range of 0-4000 cm -1 using a 50 mW single mode 532nm laser.Details are given in Thomas et al. 2022 [1,2].Note here that the lowfrequency portion of the Raman spectrum is, according to Tuschel (2019) [3], the most efficacious for characterizing, differentiating, and screening polymorphs (here SiC) by Raman spectroscopy.Furthermore, the polarization/orientation (P/O) micro-Raman spectroscopy is complementary to micro-X-ray diffraction.According to Tuschel (2012) [4], this method should be used when X-ray analysis is not practical or possible (micro-needles and mineral globules depth in the sample volume). SampleThe beryl-quartz sample material comes from the Sauberg mine near Ehrenfriedersdorf in the Erzgebirge region/Germany.Details are given in Thomas (2023) [5].Noteworthy is that the synchronously grown moissanite whiskers in beryl characterize the beryl-quartz paragenesis. ResultsDuring the study of moissanite [SiC] whiskers simultaneously grown in a small beryl-quartz vein related to the Variscan tin deposit, Ehrenfriedersdorf/Erzgebirge, Germany, the author Thomas [5] found a new fluid inclusion type in beryl formed by a necking-of process [6].That means both inclusions shown in Figure 1 formed from a primarily homogeneous phase, probably stishovite, trapped during the crystal growth of beryl.The density of both minerals, stishovite and cristobalite, is 4.35 vs. 2.20 g/cm 3 , respectively [7].It is well known that stishovite formed at the lower crust would never be preserved over geological time at low pressure and temperature [8].

Spherical crystals in minerals from prismatine-bearing rock from Waldheim, including ultrahigh-pressure (UHP) minerals such as stishovite and coesite, were previously described in uncommon crustal environments. To determine if this was an outlier phenomenon, we searched for equivalent inclusions in other rocks, which we indeed discovered in a Variscan tin-bearing granite sensu stricto from the Erzgebirge/Germany. The identification of more examples of this phenomenon implies a novel, very rapid transcrustal transport mechanism, which, however, is not unique. We demonstrate the unusual occurrence of UHP minerals (moissanite, diamond, lonsdaleite, stishovite, coesite, kumdykolite, and cristobalite-II) in topaz the investigated granitic samples, which reflects the direct interaction of mantle and crust via supercritical fluids or extremely volatile-rich melts. Mostly, the UHP minerals we recognized occur as tiny inclusions in moissanite. The trapping by this mineral prevents a fast reaction in an exogenous environment.

In the Neyriz area of southern Iran unusual skarns are found above serpentinised peridotites at the contact with crystalline limestones. They have been interpreted as the high-temperature product of intrusion by hot peridotite into limestones, as low-temperature rodingites (the product of calcium metasomatism associated with serpentinisation), or a fortuitous juxtaposition of unrelated rocks. Their age is not known. The skarns are wollastonite-pyroxene-calcite rocks in which dark green pyroxenes are fassaites with high Al, Fe and Ti with high Ca-Tschermak's components. The field relations, textures, mineral assemblages and compositions, and melt inclusions in wollastonite and fassaite indicate the skarns formed by melting at the contact between peridotites and limestones with retrograde reactions during cooling forming garnet and anorthite. There are uncertainties in temperature estimates since pressure, XCO2 and other compositional variables are unknown, but melting temperatures were likely to have been close to 1100°C with garnet formation at approximately 900°C. Later alteration of some skarns and formation of rodingites close to the limestone-peridotite contacts occurred during low-temperature Ca metasomatism, probably after emplacement of the ophiolite during Zagros collision. A hot intrusive origin for the skarns appears incompatible with an arc-related supra-subduction origin of the ophiolite inferred from geochemical studies, but recent work in eastern Indonesia shows that during late Neogene subduction rollback, melts formed above hot mantle that intruded highly extended continental crust in a forearc setting. The scale, timing and temperatures of melting and metamorphism are very similar to those of the Late Cretaceous Neyriz ophiolite.

For the origin of such curves, a clear answer could not given.At this time, the necessary analytical technique was still in it's infancyhowever, the evidence of the characteristic relationship between water content and temperature increases significantly year to year.Applying reduced parameters (T/T C ) displays relatively good comparability for different granite and pegmatite systems (Figure 1) see also Figure 2 in Thomas and Davidson, 2015) [3].So, a more universal relationship is probably.However, demonstrating such curves was the first step to solving this puzzle because a deeper origin is behind the solvus curves (temperature versus water concentration).Here, we explicitly use the water concentration because the density decreases and is not

technique because water-rich melt inclusions show the tendency to leak or decrepitate during heating on the microscopic heating stage due to the growing pressure inside the inclusions.

In this contribution, we show that in miarolitic pegmatites during the crystallization of water-rich melts, samples of these mineral-forming melts were trapped in the form of water-rich melt inclusions, preserved primarily in quartz. The bulk concentration of water and the temperature are the system-determining parameters since from their analysis it follows that these melt inclusions depict pseudo-binary solvus curves in the coordinates of temperature and water concentration. Furthermore, using reduced coordinates (H2O/H2Ocrit vs. T/Tcrit) most melt inclusions of the studied pegmatites plot very well in a standardized and reduced solvus curve. The existence and formation of such uniform solvus curves is an expression of crystallization processes under nearly equilibrium conditions. However, many trace and some principal elements of the melt inclusions trapped near the solvus crest [H2O/H2Ocrit from 0.5 to 1.5 and T/Tcrit > 0.95] show unusual distributions, with very well-defined Gaussian and/or Lorentzian curves, characterized by defined area, width, offset, and height. This has been shown in many natural examples obtained from pegmatites. Only the offset values represent near-equilibrium conditions and corresponding element concentrations, which are equivalent to the regional Clarke number (Clarke number or Clark is the relative abundance of a chemical element, typically in the Earth's crust). We interpret these distributions as explanation for some extraordinary-chemical properties in this critical region: principally extremely high diffusion rates, low dynamic viscosity and extremely low surface tension. Near the critical point, we have both space and time-related non-equilibrium and equilibrium processes close together. Furthermore, we can show that the Gaussian and Lorentzian distribution are first approximations of the specific element distribution because at the critical point the enrichment of some elements reaches such an extent that the Gaussian and/or Lorentzian curves degenerate into a vertical line (are asymptotic to the concentration axis), which is determined by the maximum solubility of a species in the supercritical melt-water system. The highest concentration of Be, as an example, was observed in Ehrenfriedersdorf melt inclusions: 71490 ppm Be.

For the first time in the sixty years since the synthesis of stishovite, we report unambiguous evidence of stishovite formed in the deep Earth. A minimum pressure of about 7.5 GPa at 1000 °C is necessary for the formation of stishovite, corresponding to a depth of about 230 km. In this manuscript we report the identification of stishovite along with coesite as inclusions in mineral grains from the Waldheim granulite. This implies that the stishovite was transported upwards, probably very rapidly to a depth of about 130 km, corresponding to the highest pressure indicated by newly identified coesite in the prismatine of the Waldheim granulite, and continuing up to the depth of emplacement of the Waldheim prismatine granulite. The analysis of the Raman spectra obtained from a metastable trapped stishovite micro-crystal show that all the diagnostic Raman bands are present. However, given the metastability of the stishovite at room temperatures and pressures, this mineral breaks down step-by-step into stable polymorphs, first coesite and then quartz and cristobalite, during the Raman stimulation. The rare coesite crystals in prismatine have also resulted from the irreversible transformation from stishovite. Although the Waldheim occurrence may be unique, we suggest that Raman analysis of co-trapped crystals in similar deep-seated rocks, an area of limited previous research, may prove an important innovation in the study of mantle processes.

With homogenization experiment (700°C, 2 kbar) on polished thin sections of emeralds from the Habachtal we demonstrate that the primary crystallization of emerald started at significantly higher temperatures than previously assumed.This experiment confirms the prediction in the precursor publication on this subject.Supercritical conditions around 700°C and 5 kbar fix the start point for the emerald crystallization.

This work presents a study of an unusual synthetic diamond sample, where calcite is the main phase in addition to diamond. Using Raman spectroscopy it can be shown that in addition to diamond carbon forms four different generations: highly ordered graphite-II, lower ordered graphite-I as spandrel between different mineral grains, weakly-ordered carbonaceous material as graphite-III and the hexagonal diamond lonsdaleite (here graphite-IV) as last formation in calcite. Graphite-III can be found mainly in the calcite body. According to the fine dispersion of this carbonaceous material and the arrangement on grain boundaries, we assume that carbon was dissolved in the calcite melt, and that by the activated state of carbon in the calcite melt the formation of diamond is favored near 1760°C, and 6.8 GPa. Lonsdaleite as minor phase may have been formed as an longlived intermediate state under standard conditions between graphite and diamond. Evidence shows that there are two different lonsdaleite phases (possibly hexagonal and monocline) present. The prevailing diamond is characterized by the first-order Raman line at 1333 cm-1. However, there are also present diamonds with the first-order Raman line down to 1310.6 cm-1, corresponding to 13C = 0.511. Significantly there is the strong decrease of the optical damage threshold with increase of the 13C content.

Análises de Elementos de Terras Raras (ETR) com microssonda eletrônica em xenotima, monazita, zircão, torita e uraninita de diferentes fácies de granitos pegmatíticos, supostos serem fonte de pegmatitos complexos de elementos raros (REL) na Província |Pegmatítica da Borborema (PPB) no Nordeste do Brasil, mostraram que a xenotima e monazita são os acessórios mais frequentes com significativa de (ETR). Conteúdos médios de Nd e Eu em monazita são respectivamente de 13,06 e 0,54 % peso dos óxidos e de Dy, Yb, Gd, e Er respectivamente de 4,77, 3,39, 3,15 e 3,86 em xenotima, considerando apenas os óxidos de ETR mais caros no mercado. Os outros acessórios analisados, como zircão, torita, uraninita não apresentaram teores significativos de ETR. As reduzidas frequências modais da xenotima e monazita tanto nos granitos pegmatíticos como nos próprios pegmatitos tornam uma exploração das rochas duras impraticáveis. Os minerais com maior enriquecimento de ETR poderiam ser concentrados e explotados em placeres fluviais no âmbito da Província Pegmatítica. Há também a possibilidade de enriquecimento dos ETR a partir dos granitos parentais e pegmatitos na interseção dos plateaus paleo-geomorfológicos culminados pelos sedimentos siliciclasticos e caulinizados da Formação Serra dos Martins. Isto porque, na inconformidade na base da mesma ocorreu lateritização e intensa e profunda caulinização no embasamento cristalino subjacente, em condições similiares às das jazidas de “adsorção iônica” (hoje também conhecidas como “hospedadas em regolito caulinizado”, como Zudong, maior jazida de terras raras pesadas) na China.

The emerald mineralization in the Habachtal (Austria) is geologically and tectonically complex, and previous investigators have identified fluid inclusion evidence for a hydrothermal/metamorphic origin for the emeralds. In this paper we report the discovery of emeralds with a distinctly different inclusion population including melt inclusions, which demonstrates that at least some and probably most of the emerald mineralization in the Habachtal occurred from an extremely fluid-rich pegmatite-like aluminosilicate melt under supercritical conditions, at high temperatures and moderate pressures (~700 °C, 5 kbar). This conclusion is based on the presence of very highly-ordered graphite, and extremely water-rich melt inclusions in emerald. The Lorentz distribution of MgCO 3 against the water concentration is a very robust proof for the supercritical state. We suggest that the purely metamorphic model, based on the extrapolation of fluid inclusion data to the regional metamorphic conditions (550 °C and 5 kbar) by some previous investigators are inconsistent with our finding of high-temperature indications (well-ordered graphite, high-temperature fluid inclusions and melt inclusions). This apparent conflict suggests a more complex situation and requires a re-investigation of the emerald genesis in the Habachtal deposit.