Carbon Isotope Characteristics as Evidence of an External Source of High-Temperature Granitoids in Granulite Complexes

Doklady Earth Sciences - Data on the carbon isotope composition of graphite and CO2 from inclusions in quartz of granitoids of the Southern Marginal Zone (SMZ) of the Limpopo granulite belt, South...     

Phosphates of the Chalotskoe Pegmatite Deposit,Transbaikal Region

A number of rare phosphates have been found in specimens from the Chalotskoe pegmatite deposit, Transbaikal region, Russia: väyrynenite, MnBe[PO₄](OH,F); parascholzite, CaZn₂[PO₄]₂ · 2H₂O; messelite, Ca₂(Fe²⁺,Mn)[PO₄]₂ · 2H₂O; eosphorite, MnAl[PO₄](OH)₂ · H₂O; moraesite, Be₂[PO₄](OH)4H₂O; and fluorapatite. Väyrynenite forms pink grains 2–3 mm in size, less frequent prismatic crystals up to 0.8 × 3.0 cm, and spheres up to 3 mm in diameter. Parascholzite occurs as pockets up to 0.6 × 1.0 cm composed from snow-white small grains. Messelite forms pale yellow honeycomb grains and poorly shaped crystals up to 1 mm. Eosphorite has been seen in the Chalotskoe pegmatites before, but it has not been studied in detail. It occurs as red-brown prismatic crystals up to 8 cm in length, occasionally forming openbook- like aggregates and pink to pale pink grains up to 5 mm in size. Moraesite forms snow-white fibrous aggregates up to 5 × 6 mm, together with white spheres and short prismatic crystals of fluorapatite up to 1 mm. Microcline, albite, quartz, muscovite, beryl, schorl, almandine-spessartine, columbite-(Fe), and bertrandite are associated minerals. Väyrynenite and parascholzite are found for the first time in Russia.

     

Beitrag zur quantitativen Analyse von Mineralphasen mittels Röntgendiffraktion

Zusammenfassung Bei der Durchführung quantitativer Gemenge-Analysen mit Hilfe der Röntgendiffraktionsmethode kann man den Massenschwächungskoeffizienten (^*) verwenden, den man bei der Röntgenfluoreszenzanalyse Röhrenhauptlinienverfahren vonSchroll-Stepon erhalten hat. Er wird von der Wellenlänge der Röntgenfluoreszenzstreustrahlung auf die Wellenlänge der Diffraktionsröhre transformiert. Ein Intensitäts-Konzentrationsdiagramm, in dem die Intensität der gewählten Diffraktionslinie durch das Produkt von Intensität und dem jeweiligen Wert von ^* ersetzt wird, ergibt eine allgemeingültige Eichgerade. Als Beispiel werden Messungen an Zweistoffsystemen wie Magnesit-Quarz, Albit-Quarz, Calcit-Quarz, Stilpnomelan-Quarz und Siderit-Quarz angeführt.Die vorgeschlagene Methode ist für kombinierte Diffraktions- und Röntgenfluoreszenzanalysen sehr zweckmäßig.

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Summary Applicating the quantitative X-ray-diffraction-analysis für mixtures of minerals the use of the mass absorption coefficient (^*) is possible, which is received by the X-ray-fluorescence-analysis of the same sample following the method proposed by the authors. The mass absorption coefficients must be transformed to the new wave length of the X-ray-diffraction tube. In the intensity-concentration-diagram the intensity is substituted by the product of intensity and mass absorption coefficient. An uniform standard line is received, as the measurement of quartz shows in the systems of two-substances, such as magnesite-quartz, albite-quartz, calcite-quartz, stilpnomelan-quartz and siderite-quartz.The proposed method is very useful for the combined X-ray-diffraction and X-ray fluorescence analysis.

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Experimental Study of the Formation of Chromium-Bearing Priderite and Yimengite as Products of Modal Mantle Metasomatism

Doklady Earth Sciences - The results of experiments on the synthesis of exotic titanates (priderite and yimengite) simulating metasomatic conditions of alteration of the mantle minerals (chromite...     

Isotope Characteristics of Carbonates from Rocks of Greenstone Belts as an Indicator of a Possible Source of Fluids in Precambrian Granulite Complexes: An Example from the Giyani Greenstone Belt and the Limpopo Granulite Complex,South Africa

Doklady Earth Sciences - Data on the carbon and oxygen isotopic composition of carbonates from the rocks of the Giyani greenstone belt, Kaapvaal craton, South Africa are presented. This belt is...     

Zinc-rich and copper-bearing amphiboles from sulfide-free ore occurrences of the Pelagonian Massif,Republic of North Macedonia

Mineralogy and Petrology - This paper describes specific features of isomorphism of unusual amphiboles containing up to 23 wt% ZnO and up to 1.3 wt% CuO from sulfide-free...     

Open and coastal seas interactions south of Japan represented by an ensemble Kalman filter

We investigated the feasibility of the ensemble Kalman filter (EnKF) to reproduce oceanic conditions south of Japan. We have adopted the local ensemble transformation Kalman filter algorithm based on 20 members’ ensemble simulations of the parallelized Princeton Ocean Model (the Stony Brook Parallel Ocean Model) with horizontal resolution of 1/36°. By assimilating satellite sea surface height anomaly, satellite sea surface temperature, and in situ temperature and salinity profiles, we reproduced the Kuroshio variation south of Japan for the period from 8 to 28 February 2010. EnKF successfully reproduced the Kuroshio path positions and the water mass property of the Kuroshio waters as observed. It also detected the variation of the steep thermohaline front in the Kii Channel due to the intrusion of the Kuroshio water based on the observation, suggesting efficiency of EnKF for detection of open and coastal seas interactions with highly complicated spatiotemporal variability.     

Fractal characteristics of the ULF emissions along a meridian profile, based on the 210 MM stations data

Fractal analysis of magnetic records (1 Hz sampling rate) of 5 stations (Guam, Moshiri, Paratunka, Magadan, and Chokurdakh) located along the 210 magnetic meridian (210 MM) has been performed using the Higuchi method. The period of 22 months (October 1992 to July 1994) that embodies the date of the strong Guam earthquake of 8 August1993 has been considered. A comparison of the ULF emissions scaling parameters (spectral exponents β and fractal dimensions D) obtained at different latitudes has been made. Dependence of β and D on the Kp index of geomagnetic activity has been analyzed for each of the 24 local time intervals. It is revealed that D decreases ( β increases) with increasing geomagnetic activity at all stations, but the rates of decrease (increase) are different at different stations and in different time intervals. It is shown that the evening, night and early morning hours are preferable to study magnetospheric effects, whereas the noon hours are the most suitable for the analysis of lithospheric effects. A possibility of using the data of the 210 MM stations as reference materials for the Guam seismically active area is discussed.