Results 41 to 50 of about 5,323 (197)

Stable (C, O, S) isotopes and whole-rock geochemistry of carbonatites from Alto Paranaíba Igneous Province, SE Brazil

Brazilian Journal of Geology
: The present work investigates the relationship between whole-rock geochemistry and stable isotope composition from carbonatites belonging to the Tapira, Araxá, Salitre, Serra Negra, Catalão I, and Catalão II alkaline-carbonatite complexes of the Alto ...
Caroline Siqueira Gomide, José Affonso Brod, Lucieth Cruz Vieira, Tereza Cristina Junqueira-Brod, Ivan Alejandro Petrinovic, Roberto Ventura Santos, Elisa Soares Rocha Barbosa, Luis Henrique Mancini   +7 more
doaj   +1 more source

Near‐Synchronous Cambrian Evolution of the Transbrasiliano‐Kandi‐4°50′ Shear Zone in South America and Africa

Terra Nova, EarlyView.
ABSTRACT The Transbrasiliano‐Kandi‐4°50′ (TK4) shear zone in western Gondwana crosscuts South America and NW Africa for at least 6000 km. Despite its impressive size, the timing of the main episode of dextral ductile shearing is uncertain. We present detailed in situ multi‐mineral geochronology of mylonites from both Brazil and Algeria supporting that ...
F. A. Caxito, B. V. Ribeiro, F. Alkmim, A. Deramchi, C. L. Kirkland   +4 more
wiley   +1 more source

Genesis of apocarbonatitic titanium metasomatites of the Petyayan-vara rare-earth occurrence (Vuoriyarvi, the Kola Region)

Vestnik MGTU, 2018
The objects of the study are apocarbonatitic titanium metasomatites ("titanium carbonatites") associated with the rare earth carbonatites of the Petyayan-Vara area of the Vuoriyarvi complex (the Kola region).
Kozlov E. N. , Fomina E. N. , Sidorov M. Yu. , Kirkin V. V.   +3 more
doaj   +1 more source

Facial accessory of high-titanium magnezium-ferruginous micas as one of evaluation criteria of metamorphic and magmatic rocks rare-metall specialization

Литосфера, 2015
Type-chemical features of high-titanium magnezium-ferruginous micas of granulites, mafite-ultramafites, alkaline rocks, and carbonatites are considered.
A. I. Belkovsky
doaj   +2 more sources

MINERALS ASSOTIATIONS AND COMPOSITIONAL HETEROGENEITY OF ZIRCON FROM MIASKITE-CARBONATITE COMPLEX OF THE VISHNEVYe MOUNTAINS, SOUTH URALS [PDF]

Минералогия, 2019
In alkaline rocks, pegmatites and carbonatites of the Vishnevye Mountains, zircons co-crystallized with rock-forming silicates (feldspars, nepheline, annite, etc.), as well as with some other minerals (pyrochlore, magnetite, ilmenite, apatite, monazite ...
V.I. Popova, V.A. Popov, V.A. Kotlyarov
doaj   +1 more source

Uma síntese sobre o magmatismo alcalino do Paraguai Oriental [PDF]

, 2013
Alkaline magmatism occurs in six distinct areas of Paraguay and forms bodies of variable size, shape, composition and age. The oldest rocks are found in the north and correspond to the Permo-Triassic Alto Paraguay Province (241 Ma). Four Early Cretaceous
Chiaramonti, Piero Comin-, Fernandez, Victor Velazquez, Gomes, Celso de Barros   +2 more
core   +1 more source

Magnetic and radiometric signatures of alkaline rocks and gabbros from the Ponta Grossa Arch, southeastern Paraná Basin, Brazil

Brazilian Journal of Geology, 2021
We present airborne magnetic and radiometric characteristics of some igneous suites from the Ponta Grossa Arch Alkaline Province (southern Brazil), namely the Bairro da Cruz, Banhadão, Barra do Itapirapuã, Mato Preto and Tunas complexes, Barra do ...
Vinicius Antunes Ferreira da Silva, Francisco José Fonseca Ferreira   +1 more
doaj   +1 more source

Rare Earth Elements (REE) Deposits Associated with Great Plain Margin Deposits (Alkaline-Related), Southwestern United States and Eastern Mexico

Resources, 2018
W.G. Lindgren in 1933 first noted that a belt of alkaline-igneous rocks extends along the eastern edge of the Rocky Mountains and Basin and Range provinces from Alaska and British Columbia southward into New Mexico, Trans-Pecos Texas, and eastern Mexico ...
Virginia T. McLemore
doaj   +1 more source

Genesis of the Bayan Obo Fe-REE deposit: evidence from Mg isotope and geochemistry of siderite carbonatites, Inner Mongolia, China

Frontiers in Earth Science
The Bayan Obo Fe-REE deposit, a world-renowned giant polymetallic ore concentration area, is located on the northern edge of the North China Craton, which borders on the Central Asian orogenic belt.
Chenghao Ren, Hongxiang Jia, Qunmao Zhou, Hongquan She, Jinwen Li, Baoliang Li   +5 more
doaj   +1 more source

The Grønnedal-Ika Carbonatite-Syenite Complex, South Greenland: Carbonatite Formation by Liquid Immiscibility [PDF]

, 2017
The Grønnedal-Ika complex is dominated by layered nepheline syenites which were intruded by a xenolithic syenite and a central plug of calcite to calcite-siderite carbonatite. Aegirine-augite, alkali feldspar and nepheline are the major mineral phases in
HALAMA, RALF, MARKL, GREGOR, SIEBEL, WOLFGANG, VENNEMANN, TORSTEN   +3 more
core