Results 1 to 10 of about 10,226 (223)

Geology and geochemistry of the Redrock Granite and anorthosite xenoliths (Proterozoic) in the northern Burro Mountains, Grant County, New Mexico, USA [PDF]

Bulletin of the Geological Society of Finland, 2002
Mineral ages from the A-type granites and anorthosite xenoliths in the Redrock area in the northwestern Burro Mountains in southwestern New Mexico cluster around ~1220–1225 Ma and provide yet another example of bimodal igneous activity during this time ...
V.T. McLemore, N. Dunbar, P.J. Kosunen, O.T. Rämö, M. Heizler, I. Haapala   +5 more
doaj   +3 more sources

Pegmatites and alkali feldspar granites as sources of industrial K-feldspar: A study from Borucu, Aksaray, Central Türkiye

Bulletin of the Mineral Research and Exploration
The Borucu (Aksaray) region, within the Central Anatolian Crystalline Complex, comprises a variety of rocks, including granite, alkali feldspar granite (AFG), pegmatite, and aplite dikes.
Gökhan Demirela, Mustafa Haydar Terzi, Ahmet Fatih Oskay   +2 more
doaj   +3 more sources

Skeletal quartz and dendritic biotite: Witnesses of primary disequilibrium growth textures in an alkali-feldspar granite [PDF]

Lithos, 2019
Abstract We describe a case of S-type alkali-feldspar granite (quartz/K-feldspar/plagioclase/ biotite/garnet ∼ 30/35/20/13/2 vol%) showing skeletal and dendritic textures. It consists of three nested units distinguishable by the size of biotite crystals: a first-emplaced unit characterized by small biotite flakes (0.4–9 mm); a second unit with cm ...
François Faure
exaly   +3 more sources

Microtextures of alkali feldspar in the Tanakami granite, Southwest, Japan and their formation processes

Ganseki Kobutsu Kagaku, 2005
Alkali feldspars in the Tanakami granite, southwest Japan, contain a complicated fine-scale mixture of various micro-textures; lamellar crypto- and micro-perthites and micropore-rich patch perthites. Mineralogical examination mainly by TEM and SEM disclosed that there are two formational stages of these micro-textures, the subsolidus cooling stage and ...
Kan HASHIMOTO, Junji AKAI, Satoshi NAKANO   +2 more
exaly   +3 more sources

A mineralogical perspective on the granite alkali feldspar megacrysts paradox

Lithos
Alkali feldspar megacrysts (commonly named K-feldspar) are a distinctive feature of many plutonic rocks. Yet, there is still no consensus on their origin. Two main contrasting explanations have been proposed so far: (i) the megacrysts form late during the crystallization history of the plutonic rock in which they occur and attain their large size in a ...
Idini, A., Fancello, D., Mameli, P., Ferrero, S., Cuccuru, S., Casini, L.   +5 more
exaly   +4 more sources

Petrography and geochemistry of the topaz-bearing granite stocks in Artjärvi and Sääskjärvi, western margin of the Wiborg rapakivi granite batholith [PDF]

Bulletin of the Geological Society of Finland, 2002
The Artjärvi and Sääskjärvi granite stocks at the western margin of the Wiborg rapakivi batholith are multiphase rapakivi granite intrusions in which the most evolved phase is topaz-bearing granite.
S. Lukkari
doaj   +3 more sources

Pseudomorphism of alkali feldspar to biotite from the alkaline nana complex granite in Cameroon

Discover Geoscience
Alkaline complexes all over the world generally are enriched in high–field strength elements and rare earth elements. This enrichment can be accounted for by magmatic processes, but, many of these complexes display evidence of hydrothermal alteration. In
Pauline Nguet Wokwenmendam, Emmanuel Njonfang, Amidou Moundi, Benjamin Ntieche, Caroline Neh Ngwa, Zakari Nchouwet, Domenico Cozzupoli   +6 more
doaj   +2 more sources

Petrology and tectono-magmatic setting of Zorrati granitoid, southwest of Birjand (East of Lut block) [PDF]

پترولوژی, 2023
The Zorrati granitoid (ZG) pluton exposed on the eastern edge of the Lut block trending north-south. The Lut block surrounded in the north by the Darone fault, in the south by the Jazmurian fault and in the east and  the  west by Nahbandan and Naiband ...
Ebadolah Toulabi Nejad, Ahmad Ahamadi Khalaji, Mohammad Ebrahimi, Habib Biabangard, Rasoul Esmaeili   +4 more
doaj   +1 more source

Discrimination of Neoproterozoic granitic-phases in Southern-Sinai, Egypt. Remote sensing, petrography and geochemistry

Egyptian Journal of Remote Sensing and Space Sciences, 2021
At Sharm El-Sheikh area a unique association of Neoproterozoic Younger granitic phases is found. These granitic rocks are petrographically identified as monzogranite, syenogranite, alkali feldspar granite, and riebeckite granite.The magma sources of ...
N.I. Abd El Ghaffar, Heba El-Bagoury, D. Sadek Ghabrial, Wael Abdelwahab, Ali I.M. Ismail   +4 more
doaj   +1 more source

Geochronology and geochemistry of the Shanagen hydrothermal vein-type Mo deposit in Derbugan metallogenic belt of the NE China and their geological significance

Frontiers in Earth Science, 2023
The Shanagen hydrothermal vein-type Mo deposit belongs to the Derbugan metallogenic belt, which is located in the Ergun block, NE China. The Mo mineralization is mainly developed in sericitized quartz siltstone around alkali-feldspar granite.
Yunxia Wu, Yunxia Wu, Yunxia Wu, Yu Liu, Yu Liu, Aoran Liu, Aoran Liu, Lifu Tian, Lifu Tian, Yasheng Ye   +9 more
doaj   +1 more source