Results 11 to 20 of about 50,106 (261)

Metamorphic and metasomatic evolution of the Western Domain of the Karagwe-Ankole Belt (Central Africa) [PDF]

, 2020
The tectonometamorphic evolution of the Western Domain of the Karagwe-Ankole Belt, containing widespread granite-related W-Nb-Ta-Sn mineralization in pegmatites and hydrothermal quartz veins of Early Neoproterozoic age, is largely unknown.
Dewaele, Stijn, Hulsbosch, Niels, Muchez, Philippe, Van Daele, Johanna   +3 more
core   +1 more source

Amphibole and biotite of melanocratic rocks from the Ural granitic massifs: composition, relationship, petrogenetic consequences

Литосфера, 2020
Research subject. The article discusses the features of the relationship between biotite and amphibole on the example of magmatogene melanocratic rocks from a number of granitoid massifs of the Urals. These rocks form xenoliths and synplutonic intrusions
S. V. Pribavkin
doaj   +1 more source

Occurrence of a Likely Tuff Bed between the Middle and Upper Siwaliks, Taunsa area, Dera Ghazi Khan, Eastern Sulaiman Range, Pakistan

International Journal of Economic and Environment Geology, 2020
A likely tuff bed lies along the gradational contact of the Middle and Upper Siwaliksineastern Sulaiman Range, Taunsa areaofDera GhaziKhan district, Pakistan.
Rahman Ullah, Nie Fengjuin, Zhang Chengyong, Saqib Izhar, Idrees Safdar, Zhang Xin, Asim Ali
doaj   +1 more source

Determination of physicochemical conditions and role of fluids in evolution of Geysour granitoid (eastern Gonabad), using biotite mineral chemistry

Journal of Economic Geology, 2021
Introduction The chemical composition of biotite in mineralization associated with granitoids and copper porphyry deposits is sensitive to several chemical and physical factors.
Ahmad Ahmadi Khalaji , Abdolsamad Pourmohammad , Mohammad Ebrahimi , Masoud Homam, Rasoul Esmaeili   +4 more
doaj   +1 more source

Discrimination between primary magmatic biotites, reequilibrated biotites and neoformed biotites

Comptes Rendus. Géoscience, 2005
The ternary diagram TiO 2 –FeO*–MgO (FeO* = FeO + MnO) is proposed as a quantitative objective tool for distinguishing between primary magmatic biotites and those that are more or less reequilibrated, or possibly neoformed, by or within a hydrothermal fluid.
Hassane Nachit, Abderrahmane Ibhi, El Hassan Abia, Mohcine Ben Ohoud   +3 more
openaire   +1 more source

Anomalously old biotite ⁴⁰Ar/³⁹Ar ages in the NW Himalaya [PDF]

, 2017
Biotite 40Ar/39Ar ages older than corresponding muscovite 40Ar/39Ar ages, contrary to the diffusion properties of these minerals, are common in the Himalaya and other metamorphic regions.
Grujic, Djordje, Kleeberg, Reinhard, Pfänder, Jörg, Ratschbacher, Lothar, Sperner, Blanka, Stübner, Konstanze, Warren, Clare   +6 more
core   +1 more source

Biogenic Weathering: Solubilization of Iron from Minerals by Epilithic Freshwater Algae and Cyanobacteria

Microorganisms, 2018
A sandstone outcrop exposed to freshwater seepage supports a diverse assemblage of photosynthetic microbes. Dominant taxa are two cyanophytes (Oscillatoria sp., Rivularia sp.) and a unicellular green alga (Palmellococcus sp.).
George E. Mustoe
doaj   +1 more source

A reactive assimilation model for regional-scale cordierite-bearing granitoids: geochemical evidence from the Late Variscan granites of the Central Iberian Zone, Spain [PDF]

, 2008
Regional scale biotite and cordierite-bearing granites (s.l.) in the Variscan of the Central Iberian Zone (CIZ) are spatially closely associated with cordierite-rich nebulites and cordierite-bearing two-mica granites, and with cordierite-rich high grade ...
Carnicero, A., Ellam, R.M., Stephens, W.E., Ugidos, J.M.   +3 more
core   +1 more source

The structure and petrology of the Cnoc nan Cuilean Intrusion, Loch Loyal Syenite Complex, NW Scotland [PDF]

, 2013
In NW Scotland, several alkaline intrusive complexes of Silurian age intrude the Caledonian orogenic front. The most northerly is the Loch Loyal Syenite Complex, which is divided into three separate intrusions (Ben Loyal, Beinn Stumanadh and Cnoc nan ...
Goodenough, Kathryn M., Gunn, A. Gus, Hughes, Hannah S.R., Lacinska, Alicja, McCormac, Michael, Walters, Abigail S.   +5 more
core   +3 more sources

Isotopic ages of Lentiira - Kuhmo - Kostomuksha olivine lamproite - Group II kimberlites [PDF]

Bulletin of the Geological Society of Finland, 2007
The Lentiira-Kuhmo-Kostomuksha triangle, along the Finland – Russian border and within the central part of the Archean Karelian craton, contains numerous examples of phlogopite-rich, ultramafic, mantle-xenocryst-bearing and, in some cases, diamond ...
H. O'Brien, D. Phillips, R. Spencer
doaj   +1 more source