 | Gevera, Patrick Kirita, Cave, Mark, Dowling, Kim, Gikuma-Njuru, Peter, Mouri, Hassina (2020) Naturally Occurring Potentially Harmful Elements in Groundwater in Makueni County, South-Eastern Kenya: Effects on Drinking Water Quality and Agriculture. Geosciences, 10 (2) 62 doi:10.3390/geosciences10020062 | Journal (article/letter/editorial) |
| Harmful Elements in Groundwater in Makueni County, South-Eastern Kenya: Effects on Drinking Water Quality...Management, South Eastern Kenya University, Kitui P.O. Box 170-90200, Kenya; pnjuru@seku.ac.ke Correspondence:... Abstract: Makueni County is located in the semi-arid south-eastern Kenya region characterized...by both the World Health Organization (WHO) and Kenya Bureau of Standards (KEBS) in up to 55% of the samples...health [1]. Makueni County is located in the arid and semi-arid land (ASAL) regions of Kenya that receives |
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| and granulite xenoliths from the Chyulu Hills volcanic field, Kenya: gabbro–troctolitic cumulates subjected...Ca–Al granulite xenoliths from the Chyulu Hills volcanic field, Kenya, suggest that the samples represent...in Cr and HFSE and high contents of normative plagioclase and olivine in the granulites indicate that their...positive Eu anomaly that suggests shallow-level plagioclase accumulation on the other hand. This contradiction...be reconciled by a model of compression of a plagioclase-bearing (gabbroic) protolith to mantle depths |
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| Five specimens of alkaline basalts from the Chyulu Hills were collected and analysed at the Center for...series of studies of rocks of the Gregory Rift of Kenya and of nearby areas. Saggerson (1963, 1968) studied...as basalts. Here I present selected data on the Chyulu specimens to /II~rate their compositional peculiarities...deferred until those studies are completed. The Chyulu basalt field is one of three groups of cones and...associated flows, located on the eastern flanks of the 'Kenya dome' (Baker 1965), in which the vents lie in linear |
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| 604/6 Chyulu Hills Chyulu Hills Cantal Marsabit Chyulu Hills Devès Chyulu Hills Chyulu Hills Chyulu...Hills San Carlos Vivarais Causses Chyulu Hills Chyulu Hills Chyulu Hills Marsabit Grt websterite Grt websterite...3 3 1 2 2 1 * Chyulu Hills and Marsabit are located on the eastern flank of the Kenya rift. Cantal, Devès...xenoliths (peridotites and websterites) from the Kenya rift system (East Africa), the French Massif Central...igneous evolution of the late Tertiary to Recent Kenya rift forming part of the East African rift system |
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| S3.00 Metamorphic Petrology of Xenoliths from Kenya and Northern Tanzania and Implications for Geotherms...Quaternary volcanic field of Marsabit (northern Kenya) bear strong evidence of decompression and cooling...1). Pyroxenitic xenoliths from the Quaternary Chyulu Hills are characterized by pyroxenes with exsolution...kb to 785 °C at 16 kb. Garnet peridotites from Chyulu are mostly granular. Matrix pyroxenes are devoid...meta-anorthosites to granoblastic granulites consisting of plagioclase, cpx, grt (mostly kelyphite), kyanite, and rutile |
 | Ulianov, Alexey, Kalt, Angelika, Pettke, Thomas (2005) Hibonite, Ca(Al,Cr,Ti,Si,Mg,Fe2)12O19, in granulite xenoliths from the Chyulu Hills volcanic field, Kenya. European Journal of Mineralogy, 17 (2) 357-366 doi:10.1127/0935-1221/2005/0017-0357 | Journal (article/letter/editorial) |
| in granulite xenoliths from the Chyulu Hills volcanic field, Kenya ALEXEY ULIANOV1,*, ANGELIKA KALT1...Switzerland Abstract: In basanites of the Chyulu Hills volcanic field, Kenya, hibonite is found in two xenoliths...meta-igneous granulites dominated by clinopyroxene and plagioclase. It occurs as small grains in the inner parts...other. Xenolith 1904-1 is rather coarse-grained (plagioclase porphyroblasts reach 34 mm, mafic minerals are...grt, crn, spl, qtz, sil, mullite, hibonite. Plagioclase (30-35 %), clinopyroxene (25-30 %) and garnet |
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| the lithospheric mantle below the Chyulu Hills volcanic field, Kenya Jens Hopp ⁎, Mario Trieloff, Rainer...Quaternary volcanic field of Chyulu Hills, S Kenya, c. 100 km east of the Kenya rift graben. 4He/3He ratios...subcontinental lithosphere; Kenya rift; mantle plume 1. Introduction The Kenya Rift is part of the East...doi:10.1016/j.epsl.2007.07.027 Oligocene in N Kenya (McDougall and Watkins, 1988), approximately contemporaneously...south- and eastward (Baker, 1987; Morley, 1999). The Kenya Rift graben roughly follows the contact between |
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| 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...is absent beneath this section of the southern Kenya Rift. Introduction The eastern branch of the East...petrological studies have largely focused on the Kenya dome region of the rift valley, and on the cause...these examples, it is generally accepted that the Kenya Rift is an active rift overlying an upwelling mantle |
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| widens from about 50 km, as is typical in southern Kenya, to approximately 200 km wide splitting into three...volcanics, e.g., in the Naivasha complex, Central Kenya (Davies and MacDonald, 1987). The earliest evidence...section is composed primarily of anorthoclase, plagioclase, minor augite, titanomagnetite, rare biotite...composed of Mg-rich olivine, titanian augite, plagioclase, titanomagnetite and rare apatite and amphibole...plot in a field defined by lavas from Chyulu Hills and Turkana, Kenya (Späth et al., 2001; Furman et al. |
 | Kaeser, Benjamin, Olker, Bettina, Kalt, Angelika, Altherr, Rainer, Pettke, Thomas (2009) Pyroxenite xenoliths from Marsabit (Northern Kenya): evidence for different magmatic events in the lithospheric mantle and interaction between peridotite and pyroxenite. Contributions to Mineralogy and Petrology, 157 (4) 453-472 doi:10.1007/s00410-008-0345-6 | Journal (article/letter/editorial) |
| PAPER Pyroxenite xenoliths from Marsabit (Northern Kenya): evidence for different magmatic events in the...from Quaternary basanites of Marsabit, northern Kenya, were analysed for microstructures and mineral compositions...alkaline magmatism during the development of the Kenya rift. Keywords Pyroxenite Mantle xenoliths Thermobarometry...the Marsabit shield volcano in the context of the Kenya rift magmatism (e.g., Henjes-Kunst and Altherr 1992)...indicates minerals in latestage metasomatic plagioclase-bearing reaction zones. Group V: garnet websterites |
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| nodules associated with alkaline olivine basahs, Kenya By E. P. SAGGERSON,Durban*) With 9 figures and 8...basalts and associated eclogite nodules from southern Kenya are described and attention drawn to the chemical...nodules associated with alkaline olivine basalts, Kenya Is eo~epa~aa~e nopo~ax E)}EHOfi t{eHr~r[. ABTOp...Kapiti P h o n o l i t e s Scale 0 I. . . . . 2 Chyulu B a s a lBt Sa as na dn i t e s ~ 20 I 40MILES...Cainozoic volcanic rocks in the Simba-Kibwezi area, Kenya. 891 Aufsatze where basaltic magma was generated |
 | Shinjo, Ryuichi, Chekol, Takele, Meshesha, Daniel, Itaya, Tetsumaru, Tatsumi, Yoshiyuki (2011) Geochemistry and geochronology of the mafic lavas from the southeastern Ethiopian rift (the East African Rift System): assessment of models on magma sources, plume–lithosphere interaction and plume evolution. Contributions to Mineralogy and Petrology, 162 (1) 209-230 doi:10.1007/s00410-010-0591-2 | Journal (article/letter/editorial) |
| East African Rift System Southern Ethiopia Kenya plume Afar plume African superplume Sr–Nd–Pb...least two distinct mantle plumes, the Afar and Kenya plumes, that have supported the Ethiopian and the...Ethiopia were related to melting associated with the Kenya plume and driven to their present position now under...northeastward migration of the African plate over the Kenya plume for the past 50 Myr. Plume–lithosphere interaction...and Rogers (2002) proposed a mantle plume source (Kenya plume) for the pre-rift basalts and an enriched |
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| volume volcanic events in Turkana (N. Kenya), Chyulu Hills (S. Kenya) and the Virunga province (Western...areas of elevated topography, the Ethiopia and Kenya domes, separated by the highly extended Turkana...small-volume flows in southern Ethiopia and northern Kenya (35-45 Ma; George et al., 1998; Furman et al., 2006b)...%), and reflect fractionation of a gabbroic plagioclase + olivine + clinopyroxene assemblage (Fig. 2)...(Fig. 4). Quaternary mafic lavas from Turkana, Kenya also share the same Nd isotopic range as HT2 lavas |
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| Sub-provinces in the Tertiary to Recent Volcanics of Kenya By J. B. WRIGHT ABSTRACT Three sub-provinces are...southern half of Kenya as follows :— (a) the Miocene phonolite sub-province, (b) the Mount Kenya phonolite/basanite...Available supporting evidence is discussed, both from Kenya and from similar volcanic provinces elsewhere. The...contrasted volcanic associations in southwestern Kenya :— (1) Miocene mela-nephelinites, nephelinites,...petrographic sub-provinces covering much of southern Kenya as far north as Mount Elgon :— The Miocene phonolite |
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| began propagating into northern Tanzania/southern Kenya at ~ 5 to 8 Ma (Baker 1987; Dawson 1992; Kampunzu... 85 Fig. 1 Map of northern Tanzania/southern Kenya; light gray: Pliocene—recent volcanic rocks, black:...expected, volcanism in northern Tanzania/southern Kenya (also known as the Northern Tanzania Divergence)...interval 6–16% MgO; amphibole, titanomagnetite, and plagioclase join the fractionation assemblage with further...Xenoliths erupted in recent volcanoes in Tanzania and Kenya provide the only direct information on the composition |
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| 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 |
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| those for other flood basalts and the Chyulu basalts of Kenya. Flows of the Grande Ronde Formation, which...province of southern Africa and from the Chyulu vents of Kenya. Cox and Jamieson [26] showed that the Karroo...this projection. The more-magnesian members of the Chyulu 70 / AI203÷ CaO+ No20 ["ACN"] / / MoO ACN...Compositions of rocks of the Karroo (solid circles) and Chyulu (open triangles) suites and the Columbia River...character, relative to the Karroo magmas, of the Chyulu rocks (K.G. Cox, personal communication, 1984) |
 | Casagli, Alessio, Frezzotti, Maria Luce, Peccerillo, Angelo, Tiepolo, Massimo, De Astis, Gianfilippo (2017) (Garnet)-spinel peridotite xenoliths from Mega (Ethiopia): Evidence for rejuvenation and dynamic thinning of the lithosphere beneath the southern Main Ethiopian Rift. Chemical Geology, 455. 231-248 doi:10.1016/j.chemgeo.2016.11.001 | Journal (article/letter/editorial) |
| the Turkana depression and the Anza Graben, the Kenya Rift, and Tanzania; Fig. 1a), revealed the presence...have been reported only from the Anza Graben, the Kenya Rift, and Tanzania (Dawson and Smith, 1988; Henjes-Kunst...extends from Arabian-Nubian shield to Ethiopia, Kenya, and the eastern margin of the Tanzanian craton...NW-SE oriented basins, including the Anza Graben in Kenya (Corti, 2009). Tertiary volcanism and rifting processes...probably due to the northward propagation of the Kenya Rift (Bonini et al., 2005). In the northern MER |
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| are reported from PAP including anorthosite, plagioclase–peridotite and hercynitite among others (Babu...olivine–clinopyroxene (± plagioclase) and olivine–plagioclase set in a groundmass of plagioclase–clinopyroxene–olivine–...of euhedral olivine and plagioclase set in a groundmass composed of plagioclase–clinopyroxene–olivine–biotite–magnetite;...clinopyroxene phenocrysts set in a groundmass of plagioclase–clinopyroxene–magnetite. Note a few grains of...groundmass. Eutectic crystallization of olivine, plagioclase, clinopyroxene and orthopyroxene resulted in |
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| that these seismic properties are typical of plagioclase-rich rocks. Magmatic underplating of basaltic...basaltic melts is a mechanism to form plagioclase-rich bulk composition for the Grenville crust. At the bottom...Grenville Proterozoic crust may have a unique plagioclase-rich bulk composition. We suggest magmatic underplating...r c h a e a n anorthosites occur as high-Ca, plagioclase-rich bodies and m a k e up a relatively small...z o i c anorthosites have a m u c h m o r e plagioclase-rich overall bulk composition than layered mafic |
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| differences in the contemporaneous volcanism in southern Kenya and northern Tanzania, the differences taking place...south Kenya and north Tanzania Table 8.1 summarizes the volcanic stratigraphy of southern Kenya and northern...onset of basaltic activity in Kenya (Baker et al. 1972). In southern Kenya during this period, volcanic...but the relatively large amounts of trachyte in Kenya find their equivalents in only minor amounts of...of Tanzania. Shombole, the most southerly of the Kenya central volcanoes, has more petrological affinities |
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| upper-mantle low-velocity anomaly beneath Ethiopia, Kenya, and Tanzania: Constraints on the origin of the...northern Sudan. The lower-crust xenoliths include plagioclase- and garnet-bearing mafic granulite. Ultramafic...field, NE Sudan (Fig. 1). This suite consists of plagioclase-bearing granulite and—summarized as ultramafic...from a collection of >50 pyroxenite- and >30 plagioclase-bearing xenoliths. Sample locations considered...and an “ultramafic” group. The granulites are plagioclase and occasionally quartzbearing and include both |
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| suggest that Formosan basalts originated in a plagioclase-free portion of the upper mantle and at greater...composition of eleven basaltic samples from Formosa. Plagioclase Olivine Clinopyroxene Orthopyroxene Opaque minerals*...in thin section and contain 20-50 percent of plagioclase, pyroxene, and olivine phenocrysts; abom half...eleven of these basalts are given in Table 1. Plagioclase is usually the principal mineral and occurs both...determined by the Michel-Levy method). Some plagioclase phenocrysts exhibit pronounced oscillatory zoning |
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| hibonite-spinel-corundum-hematite assemblage in plagioclase-clinopyroxene pyrometamorphic rocks, Hatrurim...hibonite have been found as an assemblage in a plagioclase-clinopyroxene rock (paralava, former hornfels)...rocks, but remains problematic for more silicic plagioclase-clinopyroxene hornfels and paralavas, for the... indicator minerals. The study of different plagioclase-clinopyroxene paralavas indicated minimal melting...spinel + hibonite assemblage in the Hatrurim plagioclase-clinopyroxene rock was described briefly in a |
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| the Gregory Rift Valley is that part lying within Kenya and northern Tanzania. The Gregory Rift Valley was...or by a series of step faults. Since, in central Kenya, the plateau rises on either side to the walls of...Gregory also recognised that the Rift Valley in Kenya was only a part of a system of rifts extending from...at zooo to ~5oo m and as high level remnants in Kenya, from ~5oo to 35oo m. The varying elevations reflect...basins (Fig. 3:2). In eastern Uganda and western Kenya these sediments are dateable by fossil vertebrates |
