First Evidence of the Post-Variscan Magmatic Pulse on the Western Edge of East European Craton: U-Pb Geochronology and Geochemistry of the Dolerite in the Lublin Podlasie Basin, Eastern Poland

The U–Pb measurements of youngest, coherent group of zircons from the Mielnik IG1 dolerite at the Teisseyre-Tornquist margin (TTZ) of East European Craton (EEC) in Poland yielded age of 300 ± 4 Ma. Zircon dated an evolved portion of magma at the late stage crystallization. It is shown that this isolated dyke from the northern margin of the Lublin Podlasie basin (Podlasie Depression) and regional dyke swarms of close ages from the Swedish Scania, Bornholm and Rügen islands, Oslo rift, Norway, and the Great Whine Sill in northeastern England, were coeval. They have been controlled by the same prominent tectonic event. The Mielnik IG1 dolerite is mafic rock with Mg-number between 52 and 50 composed of the clinopyroxene, olivine-pseudomorph, plagioclase, titanite, magnetite mineral assemblage, indicating relatively evolved melt. This hypabyssal rock has been affected by postmagmatic alteration. The subalkaline basalt composition, enrichment in incompatible trace elements, progressive crustal contamination, including abundance of zircon xenocrysts determines individual characteristics of the Mielnik IG1 dolerite. The revised age of dolerite, emplaced in vicinity of TTZ provides more evidences documenting the reach of the Permo-Carboniferous extension and rifting accompanied by magmatic pulses, that were widespread across Europe including the margin of the EEC incorporated that time into the broad foreland of the Variscan orogen.

Direct production of less than 50 IU white sugar at a cane sugar plant

With the selection of available process equipment and practicing best operating conditions, sugar of less than 50 IU can be produced at a cane mill without back-end refinery. Cane diffusers are being used which are energy efficient and produce cane juice with low suspended solids. The double sulphitation process is followed using the ejector system to obtain a better colour and turbidity removal. High efficiency, low residence time and low turbulence settling clarifier is being used for juice clarification. Syrup clarification is also used to polish the syrup further without using any colour precipitants. A 3½ stage crystallization scheme is employed. For A massecuite a seed magma of B2 sugar is used. B2 sugar is produced from B sugar as seed and syrup and dissolved B and C sugar is used. Purity of A massecuite is maintained around 90% producing a sugar of below 50 IU with 70% of the crystallizate having a size of 1200–1700 μm with low residual SO2 content.

Cl-bearing fluorcalciobritholite in high-Ti basalts from Apollo 11 and 17: Implications for volatile histories of late-stage lunar magmas.

We report the occurrence of a previously unidentified mineral in lunar samples: a Cl-,F-,REE-rich silico-phosphate identified as Cl-bearing fluorcalciobritholite. This mineral is found in late-stage crystallization assemblages of slowly cooled high-Ti basalts 10044, 10047, 75035, and 75055. It occurs as rims on fluorapatite or as a solid-solution between fluorapatite and Cl-fluorcalciobritholite. The Cl-fluorcalciobritholite appears to be nominally anhydrous. The Cl and Fe2+ of the lunar Cl fluorcalciobritholite distinguishes it from its terrestrial analog. The textures and chemistry of the Clfluorcalciobritholite argue for growth during the last stages of igneous crystallization, rather than by later alteration/replacement by Cl-, REE-bearing metasomatic agents in the lunar crust. The igneous growth of this Cl- and F-bearing and OH-poor mineral after apatite in the samples we have studied suggests that the Lunar Apatite Paradox model (Boyce et al. 2014) may be inapplicable for high-Ti lunar magmas. This new volatile-bearing mineral has important potential as a geochemical tool for understanding Cl isotopes and REE chemistry of lunar samples.

Особенности кристаллизации аморфных сплавов TiNiCu с высоким содержанием меди

Alloys of the quasi-binary TiNi – TiCu system with a copper content of 25, 30, 35, and 40 at. % were obtained by planar flow casting technique at a cooling rate of 10^6 K/s in the form of ribbons 30–50 μm thick and 10–20 mm wide. The structure and phase transformations in the alloys were studied using electron microscopy, X-ray diffraction analysis, and differential scanning calorimetry. It was found that in the initial state, the alloys with 25 and 30 at.% Cu have an amorphous-crystalline structure, undergoing a one-stage polymorphic crystallization of the amorphous state on heating in a calorimeter with the formation of austenite B2 phase, which on cooling to room temperature proceeds to orthorhombic B19 phase due to the martensitic transformation. It is shown that the alloys with 35 and 40 at.% Cu at quenching become amorphous, and upon heating, two-stage crystallization occurs (primary and eutectic) with the formation of a two-phase structure - the tetragonal B11 (TiCu) phase with a small fraction of B2 phase. Moreover, an increase in the copper content leads to a decrease in the onset temperature of crystallization.