Abstract In the Gasht-Masuleh area in Alborz Mountains, gabbroic magma intruded Palaeozoic metasediments and Mesozoic sediments crystallised as isotropic cumulate gabbros. LREE enrichment points to relatively low degrees of mantle melting depletion Ti, Nb Ta relative primitive an arc related component magma. Clinopyroxene compositions indicate MORB signatures. U–Pb zircon crystallisation ages 9...

Purple-violet gem spinels from Tanzania and Myanmar have been investigated for their gemological, spectroscopic, chemical, colorimetric characteristics. Samples TS MS both had a purple hue with pinkish or brownish secondary tone medium–strong saturation. We identified number of inclusions, including dolomite, phlogopite, forsterite in Tanzanian spinel magnesite, apatite, baddeleyite, anhydrite,...

-Hydroxyl orientation has a major influence on the strength of the ionic interlayer bonding in micas because of the strong repulsion between the hydrogen and the interlayer cation (IC). In order to determine if other factors also influence the magnitude of the interlayer bond energy, the effect due to the varying H-IC distance, as one finds, for example, between a dioctahedral and a trioctahedr...

Nanometric solid inclusions in diamond incorporated in garnet and zircon from felsic gneiss of the Kokchetav massif, Kazakhstan, have been examined utilizing electron microscopy and focused ion beam techniques. Host garnet and zircon contain numerous pockets of multiple inclusions, which consist of 1–3 diamond crystals intergrown with quartz, phengite, phlogopite, albite, K-feldspar, rutile, ap...

Geochemical, isotopic and age constraints support a comagmatic origin for Ghuweir Mafics and the Feinan A-type granites. The two rocks types, named collectively in this paper as the Feinan Ghuweir Magmatic Suite (FGMS), formed between 556 and 572Ma ago according to Rb–Sr whole-rock dating. FGMS has low Sr initial ratios, which preclude a significant contribution of much older crust in the magma...

The proposal of this research was to obtain products with higher porosity and specific surface area than the raw vermiculite for its possible application as a support material CO2 adsorption. In addition, it proposed analyze geological implications resulting from hydrothermal treatment vermiculites in relation their genesis. Hydrothermal presence CO2, at low temperature pressure conditions, car...

Abstract We report Mesoproterozoic 40 Ar– 39 Ar (whole-rock) ages of lamproites from (i) the Ramadugu field (R4 dyke : 1434 ± 19 Ma and R5 dyke: 1334 12 Ma) Krishna (Pochampalle 1439 3 Tirumalgiri 1256 Eastern Dharwar Craton (EDC) (ii) Garledinne (1433 8 Chelima (1373 6 dykes within Paleo-Mesoproterozoic Cuddapah Basin, southern India. The reported for constitute their first radiometric dates. ...