Previous geochemical and petrological studies have concluded that initially magmatic Nb–Ta mineralization is often modified by post-magmatic hydrothermal fluids; however, there still a lack of mineralogical evidence for the syenite-related deposit. From perspective minerals, pyrochlore supergroup minerals significance indicating fluid evolution alkaline rock or related carbonatite type deposits...

A detailed study of alkali-rich syenites from the Gföhl unit Moldanubian Zone in Bohemian Massif provides constraints on exact origin and character mantle source ultrapotassic magmatism Variscan orogenic root Central Europe. The are characterized by highly alkaline composition (K2O 11.3–12.7 wt%; K2O/Na2O 6.8–7.5), crust-like isotopic signatures (87Sr/86Sr335 ∼ 0.7116; εNd335 ≤ −7.8), significa...

Abstract A plagioclase megacryst containing composite crystal-glass inclusions was ejected in a Pliocene basaltic diatreme the Carpathian back-arc basin (Pannonian Basin). The grew from phonolitic melt, relics of which are preserved inclusions. Most pristine melt has undergone substantial compositional resetting by interaction with several batches low-viscosity carbonated, P-rich melilitite inf...

Abstract The Saidikulam nephrite deposit, which is famous for its high-quality white no matter in history and nowadays, located the eastern part of Western Kunlun Orogen, northwestern margin Tibetan Plateau, Yutian County, Xinjiang, China. Field investigations petrographic observations revealed presence five mineral assemblage zones from granodiorite to dolomitic marble deposit: slightly epidot...

Abstract La Réunion Island includes two major volcanic systems. About 0·5 Myr ago, Piton des Neiges volcano declined, while de la Fournaise grew on its flank. Since then the shield has produced homogeneous lavas with chemical compositions transitional between alkali and tholeiitic basalts. In April 2007, emitted a very small volume of trachytic pumice during largest historical eruption. We cond...

Li contents [Li] and isotopic composition (δLi) of mafic minerals (mainly amphibole and clinopyroxene) from the alkaline to peralkaline Ilímaussaq plutonic complex, South Greenland, track the behavior of Li and its isotopes during magmatic differentiation and final cooling of an alkaline igneous system. [Li] in amphibole increase from b10 ppm in Caamphiboles of the least differentiated unit to ...

the kuh shah prospecting area is located in tertiary volcano-plutonic belt of the lut block. more than seventeen subvolcanic intermediate to acidic intrusive rocks, diorite to syenite in composition, were identified in the study area. the intrusions are related to hydrothermal alteration zones and contain argillic, propylitic, advanced argillic, silicified, quartz-sericite-pyrite, gossan and hy...