Results 21 to 30 of about 646 (177)
Recently, von Knorring and du Bois described a vesicular lava of high carbonate content from western Uganda which shows close geochemical affinities with intrusive carbonatites. They stated: "It must be emphasized that the lavas examined are fresh and unaltered and that the carbonated nature cannot be attributed to alteration after solidification ...
Wyllie, P. J., Tuttle, O. F.
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PHOSPHATE-FLUORIDE-CARBONATE MINERALIZATION IN LAMPROITE ROCKS OF THE RYABINOVY PLUTON (CENTRAL ALDAN): MINERALOGICAL AND GEOCHEMICAL FEATURES AND ORIGIN [PDF]
Carbonate and apatite-fluorite mineral assemblages are studied in lamproite rocks from high-K Ryabinovy intrusive (Central Aldan, Russia). It is concluded that these assemblages are genetically related and belong to the same apatite-fluorite-carbonate ...
I.F. Chayka, A.E. Izokh
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Carbonatites are unusual C-rich alkaline magmas that have been reported throughout the geological record. Nevertheless, there is only one currently active carbonatite system on Earth: Oldoinyo Lengai stratovolcano in northern Tanzania (God’s mountain in ...
France, Lydéric +2 more
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Geology and Geochemistry of the Early Proterozoic Kortejärvi and Laivajoki Carbonatites, Central Fennoscandian Shield, Finland [PDF]
This paper provides for the first time extensive petrological, mineralogical and geochemical data on the early Proterozoic Kortejärvi and Laivajoki carbonatites, northern Finland, which form metamorphosed and highly strained bodies 2 and 4 km long within
J. Nykänen, K. Laajoki, J. Karhu
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[ Objective ] Carbonatites, as magmatic-origin rocks, are crucial source rocks for uranium, rare earth, and other minerals. They are widely distributed in the Xiaoqinling region of Shaanxi, giving rise to numerous large to super-large carbonatite ...
KANG Qingqing +7 more
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Remote Sensing Exploration of Nb-Ta-LREE-Enriched Carbonatite (Epembe/Namibia)
On the example of the Epembe carbonatite-hosted Nb-Ta-LREE deposit, we demonstrate the use of hyperspectral reflectance data and geomorphic indicators for improving the accuracy of remote sensing exploration data of structurally-controlled critical raw ...
Robert Zimmermann +4 more
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Ore specialization of carbonatite complexes at the Urais and Timan
The ore specialization of carbonatite complexes of Urals-Timan region has been established: niobium and rare earth-niobium - for the Urals’ carbonatite complexes, the rare-earth - for carbonatites of Timan.
I. L. Nedosekova +2 more
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The composition of apatite in the Archean Siilinjärvi glimmerite-carbonatite complex in eastern Finland [PDF]
We present a geochemical dataset and cathodoluminescence images of apatite from the Neoarchean (2610 Ma) glimmerite-carbonatite rocks from the Siilinjärvi complex, Eastern Finland. The subhedral, tapered prismatic grains are compositionally fluorapatite,
Seppo Karvinen +3 more
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MAGNETITE DEPOSITS OF THE TOMTOR (ONKUCHAKH AREA) AND KOVDOR PLUTONS: A PROBLEM OF ORE PRECARBONATITES [PDF]
The comparative characteristics of magnetite deposits of the Kovdor (camaphorite deposit) and Tomtor (Onkuchakh area) plutons, which were formed during the carbonatite stage of the formation of the plutons and can be classified «ore precarbonatites», is ...
A.V. Lapin +3 more
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ABSTRACT Based on the field relations, associated rock types and age, the carbonatite-alkaline rock complexes of India, that are spatially related to deep main faults, rifts and shear zones, have been classified in to two major groups, namely: 1. Middle – late Cretaceous, subvolcanic – volcanic complexes (Amba Dongar, Siriwasan, Swangkre,
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