 | | Report (issue) | | activity and geology of the northern sector of the Kenya Rift Valley British Geological Survey Research...activity and geology of the northern sector of the Kenya Rift Valley P N Dunkley, M Smith, D J Allen and...activity and geology of the northern sector of the Kenya Rift Valley P N Dunkley, M Smith, D J Allen and...springs along its western shores. Geographic index Kenya Suf>jecr index Geothermal exploration, geology...activity and geology of the northern sector of the Kenya Rift Valley. British Geological Survey Research |  | | Journal (article/letter/editorial) | | magmatism in both rifts, and within the interposing Turkana re Depression. Notwithstanding the independent...independent evolution of the Main Ethiopian Rift and Kenya lP Rift prior to their quaternary linkage, magmatic...evolved compositions (flood na phonolites in Kenya, rhyolites in Ethiopia) dominated the landscape...impacted the entire region from the Afar margin to Kenya, though activity in the south Jo slightly predates...silicic volcanoes. Magmatic activity within the Turkana Depression broadly parallels that in both rifts |  | | Journal (article/letter/editorial) | | situated, 12 km apart, on the western flank of the Kenya Rift Valley (McCall, 1964; Jennings, 1971; Jones...I/ Tanzania ) .Nair0bi FIG. 1. Index map of Kenya, showing location of Kilombe, K, and Londiani, L...(Sceal and Weaver, 1971), Menengai (McCall, 1967), Silali (McCall and Hornung, 1972), Ribkwo and Nasaken...there [] 9 [] 0 X 0 was no crystallization of apatite. However, there is a strong tendency for particular...lanthanide concentrations in some specimens from Eburru, Kenya. Of all the lanthanides, Ce is the most readily |  | | Report (chapter) | | Special Publications Outline of the petrology of the Kenya rift alkaline province B.H. Baker Geological Society...October 28, 2014 Outline of the petrology of the Kenya rift alkaline province B. H. Baker S U M M A R Y...eastern branch of the E African rift system in Kenya and northern Tanzania contains nearly the whole...majority of wellstudied suites of alkaline rocks in Kenya, including some unpublished data. Apart from questions...the province The alkaline volcanic province in Kenya and northern Tanzania is associated with the development |  | | 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...group, comprising the Barrier, Emuruangogolak, Silali and Paka, E-mail address: r.macdonald@lancaster...Olkaria, the southern group constitutes the Central Kenya peralkaline province (CKPP) of Macdonald and Scaillet |  | REN, M, OMENDA, P, ANTHONY, E, WHITE, J, MACDONALD, R, BAILEY, D (2006) Application of the QUILF thermobarometer to the peralkaline trachytes and pantellerites of the Eburru volcanic complex, East African Rift, Kenya. Lithos, 91 (1) 109-124 doi:10.1016/j.lithos.2006.03.011 | Journal (article/letter/editorial) | | the Eburru volcanic complex, East African Rift, Kenya Minghua Ren a,⁎, Peter A. Omenda b , Elizabeth Y...785, KenGen, Moi South Lake Road, Naivasha 20117, Kenya c Department of Earth Sciences, Eastern Kentucky...Quaternary Eburru volcanic complex in the south-central Kenya Rift consists of pantelleritic trachytes and pantellerites...+ aenigmatite + ferrorichterite + pyrrhotite ± apatite, although fayalite, ferrohedenbergite and ilmenite...2006 Elsevier B.V. All rights reserved. Keywords: Kenya; Eburru volcanic complex; Trachyte; Pantellerite; |  | Macdonald, Ray, Sumita, Mari, Schmincke, Hans-Ulrich, Bagiński, Bogusław, White, John C., Ilnicki, Sławomir S. (2015) Peralkaline felsic magmatism at the Nemrut volcano, Turkey: impact of volcanism on the evolution of Lake Van (Anatolia) IV. Contributions to Mineralogy and Petrology, 169 (4) doi:10.1007/s00410-015-1127-6 | Journal (article/letter/editorial) | | PAPER Peralkaline felsic magmatism at the Nemrut volcano, Turkey: impact of volcanism on the evolution of...open access at Springerlink.com Abstract Nemrut volcano, adjacent to Lake Van (Turkey), is one of the most...intermediate-rhyolitic magmas. Keywords Nemrut volcano · Peralkaline magmatism · Magma mixing · Open-system...peralkaline eruptive rocks at the Nemrut caldera volcano, Turkey. Nemrut is the most active centre in Turkey...both Nemrut and the adjacent subalkaline Süphan volcano. We have selected a suite of tephra samples covering |  | | 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 |  | Macdonald, R., Bagiński, B., Belkin, H.E., White, J.C., Noble, D.C. (2019) The Gold Flat Tuff, Nevada: Insights into the evolution of peralkaline silicic magmas. Lithos, 328. 1-13 doi:10.1016/j.lithos.2019.01.017 | Journal (article/letter/editorial) | | (Pouchou and Pichoir, 1991) was used for corrections. Apatite was analyzed using AC the technique outlined...FeTi-oxides, with trace amounts of biotite, zircon, apatite and chevkinite. Minor et al. (1998, p.9) listed...recorded it in comendites of the Olkaria complex, D Kenya Rift Valley, where it forms hexagonal crystals up... Although comendites from the Olkaria complex, Kenya, PT E have F contents >1 wt% (Macdonald et al...(1977) described from the peralkaline volcano PT E Emuruangogolak, Kenya Rift, syenite blocks which are closely |  | | Journal (article/letter/editorial) | | interactions in volcanic rocks from the northern Kenya rift: geochemical evidence Kurkura Kabeto a,b,)...2 ) 54 wt.%. lavas from Samburu Hills, northern Kenya rift, exhibit significant variations in major and...Elsevier Science B.V. All rights reserved. Keywords: Kenya rift; Bimodal volcanism; Sr–Nd isotopes; AFC; Mantle;...carbonatite–nephlinitic, and basaltic rocks in Kenya and adjacent areas indicate derivation from heterogeneous...Hills area is located in the eastern edge of the Kenya rift, on the northern flank of the Fig. 1. Map |  | | Journal (article/letter/editorial) | | Zartman Lithospheric thickness beneath the southern Kenya Rift: implications from basalt geochemistry Received:...samples from the ¯anks and ¯oor of the southern Kenya Rift Valley in the Lake Magadi area, and from two...plateau trachytes from the rift valley ¯oor. Central volcano samples are from Ol Esayeiti and Lenderut located...Pb=15.68±15.70; Pb/204Pb=39.56± 39.71). Central volcano lavas are more alkaline in character and include...is absent beneath this section of the southern Kenya Rift. Introduction The eastern branch of the East |  | Macdonald, R., Bagiński, B., Leat, P.T., White, J.C., Dzierżanowski, P. (2011) Mineral stability in peralkaline silicic rocks: Information from trachytes of the Menengai volcano, Kenya. Lithos, 125 (1) 553-568 doi:10.1016/j.lithos.2011.03.011 | Journal (article/letter/editorial) | | Information from trachytes of the Menengai volcano, Kenya R. Macdonald a,b,⁎, B. Bagiński a, P.T. Leat...Available online 17 March 2011 Keywords: Menengai volcano Peralkaline trachytes and rhyolites Mineral stability...silicaoversaturated trachytes from the Menengai volcano, Kenya Rift Valley. The dominant phenocryst assemblage...feldspar–hedenbergite–fayalite–titanomagnetite–apatite. Aenigmatite, amphibole and quartz occur rarely...East African Rift System. Volcanic centres in the Kenya Rift Valley where pantelleritic trachytes have been |  | | Report (volume) | | continents. Field work was conducted in Chad, Ethiopia, Kenya, Malawi, Nigeria, Sudan, Tanzania and Uganda. However...Baker, B.FL Tectonics and volcanism of the southern Kenya Rift Valley and its influence on rift sedimentation...and sedimentation in the Kenya Rift from the equator northwards to Lake Turkana ... 59 Swain, C.J., Skinner...R.T. Volcano-tectonic control on sedimentation in the Koobi Fora sedimentary basin. Lake Turkana. 85 ...landtorm evolution in a rift valley basin, northern Kenya. Frostick, L.E. & Reid, I. Evolution and sedimentary |  | | Journal (article/letter/editorial) | | identified during EMP analysis include phosphates (apatite, monazite), REE-bearing silicate (probably britholite)...Sørensen, 2005; Neumann, 1976), and Warrumbungle volcano, NSW (Duggan, 1988). a: Variation in the diops...pyroxene in felsic volcanics from the Warrumbungle Volcano, central New South Wales, Australia. Mineralogical...498–516. Macdonald, R., 2003. Magmatism of the Kenya Rift Valley: a review. Transactions of the Royal...between trachyte and carbonate in ash flow tufts from Kenya. Contributions to Mineralogy and Petrology 114, |  | | Journal (article/letter/editorial) | | Suite from the Southern Part of the Gregory Rift, Kenya Brian H. Baker 1, G o r d o n G. Goles 1, William... clinopyroxene, olivine, titanomagnetite, and apatite. The trachytes formed from evolved magmas largely...faulting. 1. Introduction The Gregory rift in Kenya is a part of the eastern branch of the Afro-Arabian...genetic associations have been distinguished in the Kenya rift alkaline province: a strongly alkaline association...transitional basalts, trachytes, and occasional Kenya-type phonolites, pantellerites, and comendites. |  | | 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...by their association with economic deposits of apatite (Kogarko) and with diamonds (Dawson; Bergman)...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 |  | Upton, B. G. J., Macdonald, R., Odling, N., Rämö, O. T., Bagiński, B. (2013) Kûngnât, revisited. A review of five decades of research into an alkaline complex in South Greenland, with new trace-element and Nd isotopic data. Mineralogical Magazine, 77 (4) 523-550 doi:10.1180/minmag.2013.077.4.11 | Journal (article/letter/editorial) | | feldspar, olivine, pyroxene, titanomagnetite and apatite; intercumulus phases include alkali amphibole,...magma chamber (or chambers) beneath a central-type volcano, exhibits various features of petrological interest...pyroxene, with subordinate titanomagnetite and apatite. The principal difference between these syenitic...iron-rich calcic clinopyroxene, titanomagnetite and apatite. Comparable assemblages are present as phenocrysts...feldspars, olivine, clinopyroxene, titanomagnetite, apatite, FIG. 9. Diagrammatic sketches of trough layers |  | Macdonald, R., Belkin, H. E., Fitton, J. G., Rogers, N. W., Nejbert, K., Tindle, A. G., Marshall, A. S. (2008) The Roles of Fractional Crystallization, Magma Mixing, Crystal Mush Remobilization and Volatile–Melt Interactions in the Genesis of a Young Basalt–Peralkaline Rhyolite Suite, the Greater Olkaria Volcanic Complex, Kenya Rift Valley. Journal of Petrology, 49 (8) 1515-1547 doi:10.1093/petrology/egn036 | Journal (article/letter/editorial) | | Rhyolite Suite, the Greater OlkariaVolcanic Complex, Kenya Rift Valley R. MACDONALD1,2*, H. E. BELKIN3, J....rhyolite dome and lava field in the south^central Kenya rift valley that has been marked over the past 20...(Olkaria), and the neighbouring centres on the Kenya Dome (Eburru, Longonot and Suswa). From Heumann...O F T H E G OVC The GOVC is part of the central Kenya peralkaline province (CKPP; Macdonald & Scaillet...with an area of crustal upwarping known as the Kenya Dome. Crustal thickness beneath the Dome is 30^35 |  | Ayalew, Dereje, Barbey, Pierre, Marty, Bernard, Reisberg, Laurie, Yirgu, Gezahegn, Pik, Raphael (2002) Source, genesis, and timing of giant ignimbrite deposits associated with Ethiopian continental flood basalts. Geochimica et Cosmochimica Acta, 66 (8) 1429-1448 doi:10.1016/s0016-7037(01)00834-1 | Journal (article/letter/editorial) | | yielded temperatures of 900°C. Application of the apatite saturation thermometer (Harrison and Watson, 1984)...Clinopyroxene ⬍ 3% Amphibole ⬍ 2% Fe-Ti-oxides ⬍ 2% Apatite ⬍0.5% Matrix Sample descriptions available on...troughs at Ba, Sr, P, and Ti indicative of feldspar, apatite, and Fe-Ti oxide fractionation. These troughs become...clinopyroxene, plagioclase, Fe-Ti oxides, and apatite, which is fully consistent with previous results...clinopyroxene, plagioclase, Fe-Ti oxides, and apatite, which is fully consistent with the phenocryst |  | | | | plagioclase, augite and Fe-Ti oxides. Minor amounts of apatite, pyrite and biotite are sometimes present. The...Leat, P.T. (1995) Petrogenesis of Silali volcano, Gregory rift, Kenya. Journal of the Geological Society |  | Jung, S., Mezger, K., Hauff, F., Pack, A., Hoernes, S. (2013) Petrogenesis of rift-related tephrites, phonolites and trachytes (Central European Volcanic Province, Rhön, FRG): Constraints from Sr, Nd, Pb and O isotopes. Chemical Geology, 354. 203-215 doi:10.1016/j.chemgeo.2013.06.026 | Journal (article/letter/editorial) | | fractionation of olivine, clinopyroxene, amphibole, apatite and titaniferous magnetite ± plagioclase ±alkalifeldspar...calcic plagioclase, clinopyroxene, magnetite and apatite. Trachytes are dominated by feldspars, some of...as a phenocryst phase, together with zircon and apatite. Phonolites are characterized by a fine-grained...green sodic clinopyroxene, amphibole, biotite, apatite and zircon. 5. Summary of compositional features...phonolites and trachytes (e.g., Panter et al., 1997). Apatite fractionation clearly controls the concentration |  | | Journal (article/letter/editorial) | | of the Late Pliocene (5·7 to 4·2 Ma) Mt Sidley volcano, Marie Byrd Land, is examined using major and trace...plagioclase, titaniferous magnetite, nepheline and/or apatite from basanite to derive 35% mugearite, 25% benmoreite...extreme Mt Sidley, an Early Pliocene composite volcano, is at the south end of the Executive Committee...through a suite of coexisting rocks at a single volcano, often because of the preponderance of either basaltic...GEOLOGY Mt Sidley (4181 m) is a large (>200 km3) volcano composed primarily of phonolitic and trachytic |  | | Report (issue) | | (Bottom) Carbonatite lava at Oldoinyo Lengai volcano, northern Tanzania. Courtesy Alexander J. Teague...upper-mantle low-velocity anomaly beneath Ethiopia, Kenya, and Tanzania: Constraints on the origin of the...and natrocarbonatite lavas at Oldoinyo Lengai volcano, Tanzania. . . . . . . . . . . . . . . . . . ....fingerprints of mantle metasomatism beneath Nyos volcano (Cameroon volcanic line) . . . . . . . . . . ....40Ar-39Ar ages and petrogenesis of the Massif d’Ambre volcano, northern Madagascar . . . . . . . . . . . . . |  | | Report (issue) | | hazard and risk assessment was n1ade of Irazu volcano. Resources and wealth creation • Britain continues...hole a11d several new licence applications ir1 County Antrim. The GSNI exhibited at the annual meeting...look at mineral prospects near Fivemiletown in County 'I.yrone, and a geochemical study of stream sediments...the release of data. The National Oil Compa11y of Kenya was assisted in the preparation of a report on petroleum...NIGERIA , �-- PHILIPPINES ETHIOPIA - UGANDA BAN KENYA � • GHANA VIETNAM TANZANIA � 4t WI • PAPUA |  | | Report (issue) | | Drilling on the Kinagoni lead-silver prospect, Kenya. 6 • • • • • • • • • • I. Establishing ground control...come from the Department of the Environment, from County Councils and from civil engineering firms. During...copies were sold, including copies of the obsolete 'county' series, now out of print, for which the Institute...British Solomon Islands Protectorate, Fiji, Jamaica, Kenya, Malawi, New Hebrides, Swaziland and Zambia. A further...completed. Apart from deposits of limestone and apatite which are already being mined or exploited, the |
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