 | | Journal (article/letter/editorial) | | com/locate/lithos Peralkaline syenite autoliths from Kilombe volcano, Kenya Rift Valley: Evidence for subvolcanic interaction...and geochemistry of syenite autoliths from Kilombe volcano indicate that they crystallized in the upper...replacement of (i) Mg–hedenbergite by aegirine–augite, Ca–aegirine and/or aegirine, (ii) fayalite by amphiboles...minerals, have been found for the first time at Kilombe together with eudialyte, nacareniobsite–(Ce) and...occurrences in Kenya. © 2006 Elsevier B.V. All rights reserved. Keywords: Syenite; Carbonatite; Kilombe; Kenya |  | | Report (issue) | | intrusion); quartz, microcline, albite, arfvedsonite, aegirine (Morro Redondo Complex, Brazil). Distribution:...Mecsek Mountains, Hungary; Los Isle, Guinea; Kilombe volcano, Kenya and Ambohimirahavavy, Madagascar. Name: |  | | Report (issue) | | MINISTRY OF NATURAL RESOURCES GEOLOGICAL SURVEY OF KENYA GEOLOGY OF THE NAKURU-THOMSON'S FALLSLAKE HANNINGTON...outside the Rift Valley (2) Drainage into Lake Baringo and Lake Hannington (3) Drainage into Lake Solai...Nakuru-Elmenteita Basin (6) Larmudiac Beds (c) Baringo-Hannington Basin (d) Solai Basin 2. Igneous Rocks...36°30'E. The area is one of the most diverse in Kenya, extending as it does from high moorlands over 9...000 feet above sea level to the hot lowlands of Baringo at little more than 3,000 feet. The north-western |  | | Journal (article/letter/editorial) | | 10% to 15% ferrorichterite, ≤10% quartz, ≤5% aegirine with about 5% of apatite, titanite, zircon, plagioclase...complex (modified from Wang et al., 1993). of aegirine. Agglomerates of ferrorichterite, titanite and...zircon, apatite and accessory amounts of quartz, aegirine, fluorite, plagioclase and Fe–Ti oxide minerals...quartz, subhedral fluorite and rarely anhedral aegirine are observed. 4.2. The Taihe pluton Granites from...titanite, aenigmatite, apatite, fluorite, ilmenite and aegirine. The alkali feldspar is euhedral to subhedral |  | | Journal (article/letter/editorial) | | elsevier.com/locate/lithos The volcano–pluton interface; The Longonot (Kenya) and Kûngnât (Greenland) peralkaline...Available online 18 March 2014 Keywords: Longonot volcano Kûngnât syenite complex Evolution of complementary...magma reservoir(s). The trachytic caldera volcano Longonot (Kenya Rift Valley) and the Kûngnât syenite complex...Kelleher and Cameron, 1990) and the Olkaria complex, Kenya (Macdonald et al., 2008; Marshall et al., 2009)...which can be considered to be a complementary volcano–pluton pair. Although the histories of the two |  | | Journal (article/letter/editorial) | | crystallization, 19ss022-1, sytnite, PPL, (h)(g) anhedral aegirine fill in the crystal framework in the (f) same...clinopyroxene; Aeg, aegirine; Arf, arfvedsonite; the sytnite, 14ss003-3, PPL, (h) anhedral aegirine fill in the...Afs, alkali feldspar; Cpx, clinopyroxene; Aeg, aegirine; Arf, arfvedsonite; Ap, line represents the boundary...◦ 0 ◦ 0 ◦ 0 ◦ 0 ◦ 7 of 21 Azores, Kilombe, Kenya Portugal 0 112 55 47” 112 55 41”and112 57...06 0.12 0.12 0.08 0.09 0.05 0.01 0.09 0.24 0.22 Kilombe, Azores, MgO 0.14 0.28 0.27 0.17 0.32 0.10 0.21 |  | | Journal (article/letter/editorial) | | a c t Young (b 1 Ma) volcanic complexes in the Kenya Rift Valley are used to outline recent progress...dome complexes, e.g. the Olkaria complex in the Kenya (Gregory) rift with an estimated volume of ~13 km...Ma) silicic complexes in the inner trough of the Kenya Rift Valley to outline recent progress in our understanding...Olkaria, the southern group constitutes the Central Kenya peralkaline province (CKPP) of Macdonald and Scaillet...structure of the crust both along and across the Kenya rift (KRISP Working Group, 1991). The crust thickens |  | | Journal (article/letter/editorial) | | Isle, Guinea (Parodi & Chevrier 2004), and Kilombe volcano, Kenya (Ridolfi et al. 2006). More recently, it...matrix with quartz, microcline, albite, fluorite, aegirine, some arfvedsonite, and combinations of several...core-to-rim compositional zoning in arfvedsonite and aegirine, and millimetric- to centimetric-sized vugs and...arfvedsonite deformed megacrystals, the latter mantled by aegirine, in a finegrained, quartz-rich matrix with microcline...microcline and albite (not shown), aegirine, arfvedsonite, and rare accessory minerals such as unidentified |  | | Journal (article/letter/editorial) | | Synchysite-(La) is described as an inclusion in aegirine from a subvolcanic alkali syenite (Negev, Israel...peralkaline syenite autoliths from the Kilombe volcano (Rift Valley, Kenya), associated with Fe- and P-rich...lanthanide mineralization at the Buru carbonatite (Kenya) and consider that in such a context synchysite...(1992) Significance of REE-mineral inclusions in aegirine from an alkali syenite, Negev, Israel. European...Exceptional rare earth element enrichments in Tahaa volcano (French Polynesia). Comptes Rendus Académie des |  | | Journal (article/letter/editorial) | | presence of trachytic differentiates and the peculiar volcano-tectonic alignments suggest an independent evolution...specifically, the eruptive centres alignment delineates volcano-tectonic trends between E–W and NE–SW, which conform...toward N–NW and S–SE with respect to the main volcano-tectonic trend; the syenitic subvolcanic intrusions...consisting of isoriented microliths of alkali feldspar, aegirine clinopyroxene, subordinate opaque minerals and...comprise alkali feldspar, nepheline, amphibole, aegirine clinopyroxene and opaques. A wide variety of minerals |  | Melluso, L., Morra, V., Guarino, V., de’ Gennaro, R., Franciosi, L., Grifa, C. (2014) The crystallization of shoshonitic to peralkaline trachyphonolitic magmas in a H2O–Cl–F-rich environment at Ischia (Italy), with implications for the feeder system of the Campania Plain volcanoes. Lithos, 210. 242-259 doi:10.1016/j.lithos.2014.10.002 | Journal (article/letter/editorial) | | hainite, Mn-aenigmatite, britholite and Ti–Zr-rich aegirine in the groundmass of the peralkaline trachyphonolites...Somma–Vesuvius (Fig. 1). To the east, the Mt. Vulture volcano is located close to Apenninian foredeep and the...ICP-2); g) sequence of magnetite– aenigmatite–aegirine in the groundmass of the St.Angelo lava; and h)...sequence of interstitial magnetite–aenigmatite–aegirine, with idiomorphic alkali feldspar and allotriomorphic...rocks or as very rare xenocrysts in trachytes, to aegirine (down to Mg# = 1), found in the fine-grained groundmass |  | | Journal (article/letter/editorial) | | aggregates of zircon, alkali feldspar, albite, aegirine, fluorite and calcite. 354 the canadian mineralogist...albite, Fig. 3b) and needle-like aggregates of aegirine-rich pyroxene2 (Fig. 2). In some samples, the...(2006): Peralkaline syenite autoliths from Kilombe volcano, Kenya Rift Valley: evidence for subvolcanic interaction...ejecta in the plinian deposits of Agua de Pau volcano (São Miguel, Azores Islands). Mineral. Mag. 67 |  | | | | for the transformation of aegirine-augite into aegirine (or augite into aegirine-augite), and for the crystallization...orientation of the sanidine crystals and/ or of the aegirine-augite needles (C/S fabrics are locally developed...phenocrysts have been partly transformed into green aegirine-augite (Gcpx); the inset shows the location of...hainite (Ha) and needle-like apatite (Ap). (e) Aegirine (Ae) interstitial to the alkali feldspar (Fsp)...nepheline and aegirine-augite with minor titanite, apatite, Fe-Ti oxides and aegirine. The phenocryst |  | | Journal (article/letter/editorial) | | Copenhagen consisted of aenigmatite coated with aegirine, leading him to conclude that Breithaupt’s (1865)...‘kölbingite’ was but a mixture of aenigmatite and aegirine. Foerstner (1881) described the new triclinic...silica-undersaturated trachyte of Warrumbungle volcano, New South Wales, Australia, which he named to...Proterozoic rocks in the Caledonides, Nordland County, Norway (Grauch et al. 1994; Burt 1994). The mineral...55 wt.% (minimum and maximum from Mangari area, Kenya and Vizianagaram, India, by Mercier et al., 1999 |  | Bianchini, Gianluca, Brombin, Valentina, Marchina, Chiara, Natali, Claudio, Godebo, Tewodros Rango, Rasini, Alessandro, Salani, Gian Marco (2020) Origin of Fluoride and Arsenic in the Main Ethiopian Rift Waters. Minerals, 10 (5) 453 doi:10.3390/min10050453 | Journal (article/letter/editorial) | | sectors of the East African Rift and other similar volcano-tectonic settings. Keywords: fluoride and arsenic;...Differentiated rhyolite magmas appeared late in the volcano-tectonic evolution of the area, marking the onset...MER, the rifting processes have formed various volcano-tectonic depressions, favouring the development...studied lithologies are amphibole, prevalently aegirine-augite clinopyroxene, aenigmatite, oxides, and...such as feldspar, subordinate quartz, amphibole, aegirine-augite clinopyroxene, aenigmatite, oxides, and |  | | Report (volume) | | 273 BAKER, B. H. Outline of the petroIogy of the Kenya rift alkaline province 293 MACDONALD,R. Quaternary...peralkaline silicic rocks and caldera volcanoes of Kenya 313 WOOLLEY, A. R. & JONES, G. C. The petrochemistry...on the peralkaline silicic central volcanoes of Kenya and also favours an origin by crystal fractionation...pyroclastic deposits around central volcanoes in Kenya often show striking variations in the abundance...on the peralkaline silicic central volcanoes of Kenya and also favours an origin by crystal fractionation |  | Melluso, Leone, Guarino, Vincenza, Lustrino, Michele, Morra, Vincenzo, de' Gennaro, Roberto (2017) TheREE-and HFSE-bearing phases in the Itatiaia alkaline complex (Brazil) and geochemical evolution of feldspar-rich felsic melts. Mineralogical Magazine, 81 (2) 217-250 doi:10.1180/minmag.2016.080.122 | Journal (article/letter/editorial) | | Mg/(Mg + Fe2+)], through rare hedenbergite, to pure aegirine (NaFeSi2O6; CaO 228 ∼0.17 wt.%; MgO ∼0.08 wt...66–77; Suppl. Fig. 2; Suppl. Table 2) to very rare aegirine (CaO ∼0.23 wt.%; MgO ∼0.03 wt.%; Na2O ∼13.4 wt...Titanium reaches its highest concentration in an aegirine (TiO2 = 2.15 wt.%); Zirconium is very low also...sodic varieties. Manganese increases with Fe in aegirine-augites up to 4.1 wt.% MnO (sample IT60), and...that the presence of arfvedsonite rather than aegirine is to be linked to a relatively lower fO2. The |
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