Biotite, the dominant ferromagnesian mineral in granitoid rocks, can be used to discriminate tectonic setting, magma types and magnetite- ilmenite series. In this study, we analyzed biotite with an electron microprobe (wavelength dispersion) from different granitoids. Intrusive rocks from Maherabad porphyry Cu-Au prospecting are meta-aluminous. Biotite from Maherabad are Mg-rich type and the ra...

new structural, metamorphic, finite strain and kinematic vorticity data for granitic gneiss and metavolcano-sedimentary rocks of thetanumaharea in the arabian shield in saudi arabia reveal a history of deformation reflecting different tectonic regimes. kinematic analysis shows their relationship to the nappe contacts between the granitic gneiss and metavolcano-sedimentary rocks and explains the...

buchitic glassy rocks appear within the skarn of contact metamorphic aureole of feshark intrusive complex situated 30 km northeast of isfahan. intrusive complex is a multistage intrusion . noritic gabbro is the first inttrusion which is invaded later on by a granitic melt. granitic melt has metasomatically altered the gabbro and as a consequence a suite of hybrid rocks like monzogabbro, monzodi...

Cement is the costlier component of concrete, and its productive process causes considerable environmental impact. Thus, alternatives are studied to reduce amount cement used. An option use optimized grain size curves aggregates, aiming achieve a higher compactness concrete. ideal distribution results in mechanical resistance providing reduction cost consumption materials, and, consequently, im...

Dark brown porous ferrotapiolite is a dominant product of alteration in pseudomorphs after primary stibiotantalite from the lepidolite pegmatite at Laštovičky, western Moravia, Czech Republic. Two compositionally distinct varieties of ferrotapiolite were recognized, a volumetrically dominant Fe3+-rich phase and a very rare Sb-rich phase. Niobium-rich ferrotapiolite, with up to 17.51 wt.% Nb2O5 ...

Single zircon dating of the Rampur metabasalts of the Larji–Kullu–Rampur window in the Lesser Himalayas yielded an evaporation age of 1800913 Ma. The zircon age is considerably younger than the previously published whole rock Sm–Nd age of 2510990 Ma, suggesting that the Sm–Nd age may be geologically meaningless and that the Sm–Nd whole rock array may have resulted from mixing. In the NW Himalay...

Nyos maar is located in the Cameroon Volcanic Line and generates a multitude of primary and secondary hazards to the local population. For risk assessment and hazard mitigation, the age of the Nyos maar eruption provides some vital information. Since previous dating efforts using a range of techniques resulted in vastly varying eruption ages, we applied thermoluminescence (TL) methods to obtain...