 | | Report (issue) | | Report No. 45 COLONY AND PROTECTORATE OF KENYA MINISTRY OF COMMERCE Ä N D INDUSTRY GEOLOGICAL SURVEY...of South Nyanza, in the south-western corner of Kenya. It is a most important area as in its northern...centre at Rangwa became the focus of a central volcano, much of which is still preserved and when traced...(2) The Kisingiri Volcano (a) The Updoming of the "Sub-Miocene" Peneplain surface under Kisingiri (b) The...The Kisingiri Volcanic Series (i) The Lower Kisingiri Nephelinite Lavas (ii) The Middle Kisingiri Pyroclastic |  | | Report (chapter) | | silicate liquids give rise to pyroxenites, ijolites, nepheline syenites and nephelinitic pyroclast-rich strato-volcanoes...around ijolites in granitic terranes, with nepheline syenite commonly formed as a contact-reaction rock.../ K i ;1:/\. - u3-'~."\ -r ~ \\ -/:/ ", KENYA u __-/~.'\- " :. / I 2 ~ i TANZANIA 9 ~ ...4- • LODWAR ~t~ MOROTO z --2 0 NAPAK ~ KENYA C e n o z o i c l a v a s and pyroclastic deposits...+ NYAMBENI I&UISHU ~ Kavirondo ~ M T . ~ A KENYA Olivine-poor volcanic A Olivine-rich volcanic |  | | Journal (article/letter/editorial) | | whole rock isochrons for the Monchique and Mt. Kenya complexes, together with a series of 87Sr/86Sr ratios...participation in the origin of nephelinites, nepheline syenites, ijolites or peralkaline oversaturated...consist of alkali gabbros, intermediate rocks, nepheline syenites, lamprophyres and peralkaline or agpaitic...nephelinites, ijolites, melilitic rocks, pyroxenites, nepheline syenites and carbonatites. The absence of calcic...the division of petrogenetic opinion regarding nepheline syenites; moreover, nephelinites and ijolites |  | | Journal (article/letter/editorial) | | Differentiation Trends in Tertiary to Recent Lavas of Kenya* By J. B. WRIGHT ABSTRACT The distribution of Tertiary...of south-west Kenya is outlined, and attention drawn to the predominance of nepheline-rich Miocene lavas...feldspar versus silica, for analysed lavas from Kenya and Tanganyika, are used to illustrate the trends...nephelinitic lavas and carbonatite complexes in Kenya is discussed and the possibility mooted that the... INTRODUCTION THE Tertiary to Recent lavas of Kenya are a typical continental sodic alkaline suite, |  | | Journal (article/letter/editorial) | | extrusive carbonatites at Rangwa Caldera Complex, Kenya G. ROSATELLI1,*,{, F. WALL2 AND M. J. LE BAS3...of the large Kisingiri nephelinite-carbonatite volcano, Homa Bay District, western Kenya (0º34’S; 34º09’E)...relationship with the nephelinites of the Kisingiri volcano. Two hypotheses are discussed. A rising silicate...EY WORDS : carbonatite, Rangwa Caldera Complex, Kenya, nephelinite. Introduction TO date, extrusive rocks...Only the Oldoinyo Lengai G. ROSATELLI ETAL. volcano (Tanzania) erupts carbonatite lavas today (Dawson |  | | Journal (article/letter/editorial) | | morphology from volcanic carbonatites in Tanzania, Kenya, Greenland, and India T. DEANS 2o Grove Park Road...identifications of similar magnetites from four localities in Kenya, one in Greenland, and one in India. Despite the...also spelled Galappo) lies at the foot of the volcano Kwaraa (also Kwaraha, or Ufiome), one of several...TINOIERET 3~ o / 0~ eNakuru 3t. L.NaivashaQ Kenya "~"-..~ l_.Mag,~li~ Tanzania L.Natron /2";OLDOINYO...nephelinite/carbonatite volcanoes (underlined) in Tanzania and Kenya. The carbonatites occur at the south-eastern foot |  | | Journal (article/letter/editorial) | | Geology, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B 5E1, Canada ABSTRACT Carbonatites are...nephelinite, ijolite, melilitolite, aillikite, nepheline syenite, liquid immiscibility, carbothermal residue...(USA), potassic syenite in the Bearpaw Mountains (USA), and peralkaline sodic agpaitic syenite at Khibina...rocks are associated with carbonatites, e.g., nepheline syenite at Mt. Brome (Canada) or Kangerdlugssuaq (Greenland)...intrusive (melteigite – ijolite – urtite suite, nepheline syenite) and extrusive rocks (nephelinite, phonolite |  | | Book (edition) | | those of the undersaturated alkalic group—the nepheline syenites and their relatives. Rare, mineralogically...Cu, barite, vermiculite, CaCOs;, fluorite, Ti, nepheline, and Zr. HISTORY OF CARBONATITE STUDIES Although...bodies of limestone intimately connected with the nepheline rocks. Generally the limestone is INTRODUCTION...the vicinity of the limestone occurrences the nepheline rocks are often also very rich in calcite, which...common in the limestone, as well as in the nepheline-syenite bodies which occur at some localities as inclusions |  | | 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...alumina with respect to alkalis and will have nepheline and/or acmite in their norms. In practice the...silica-deficient but are rarely alkali-rich. True (nepheline-normative) alkali basalts grade into hypersthene-normative...Archaean. For example, biotites from the Poohbah Lake syenite in north-western Ontario have been dated at around |  | Riley, T. R., Bailey, D. K., Harmer, R. E., Liebsch, H., Lloyd, F. E., Palmer, M. R. (1999) Isotopic and geochemical investigation of a carbonatite-syenite-phonolite
diatreme, West Eifel (Germany) Mineralogical Magazine, 63 (5) 615-631 doi:10.1180/002646199548736 | Journal (article/letter/editorial) | | and geochemical investigation of a carbonatite-syenite-phonolite diatreme, West Eifel (Germany) T. R ...erupted xenoliths of calcite-bearing feldspathoidal syenite, phonolite and sanidine and clinopyroxene megacrysts... provinces worldwide. KEYWORDS" carbonatite, syenite, phonolite, stable isotopes, radiogenic isotopes...was emplaced adjacent to an alkali-mafic maar volcano and a nephelinitic stratacone. The diatreme erupted...lapilli and ash, and carried a wide range of felsic (syenite, phonolite, sanidine) xenoliths to the surface |  | | Book | | northern portion in northern Tanzania, western Kenya, and eastern Uganda where the Nyanzian System, composed...through Rhodesia, Mozambique, Malawi, Tanzania and Kenya, and is characterised by ages of 400-700 m.y. (Cahen...rejuvenated antique sequences: the Nyanzian of Kenya (Sanders, 1965); the Bulawayan of Rhodesia (Johnson...and the Mozambique Belt in western Kenya. Bull. geol. Surv. Kenya, 7. ScureIner, G. D. L., and VAN NIgkERK...Land, within the ancient tonalitic gneisses, a syenite plug known as Bosmanskop occurs (Fig. 7) and appears |  | | Report (issue) | | Phosphorite General Age Mineralization Batemans Bay Marine chemical sediment nodular Ordovician New...Cretaceous 76 Australia Northern Territory Fannie Bay Marine chemical sediment nodular 78 Australia...pelecypods Late Miocene 121 Australia Victoria Waratah Bay Marine chemical sediment nodular 122 Australia...Magmatic/host rock age 82.9±4.2 Ma (K/Ar on alkali syenite) Appendix A OF02-156A Deposit No. Host/Associated...Age references alkaline igneous complex-nepheline syenite, dolomite, 182 pyroxenite General Comments |  | | Book | | 10.4 10.5 10.6 10.7 Chapter vi The trachyte-syenite clan 11 List 11-2 compositions associations...derived from vol- cani vicus, or the seat of a volcano. Desmarest (1771) also worked in the Auvergne and...chamber that lies 3 km beneath the caldera of Krafla volcano (Einarsson 1978: 187). been cycle, This studied...approximately 40 to 10 km beneath the summit of Kilauea Volcano, between 10 and Hawaii, 3 km and that at depths... or into dykes that feed the rift zone of the volcano. According to Moore (1983: 139) there are several |  | | Book (volume) | | pegmatite areas include the Pala area of San Diego County in California, the Nuristan area of Afghanistan...marble formed by the metamorphism of limestone. Kenya rubies (Mangari area of the Tsavo West National...provide evidence for the 1628 bc eruption of the volcano on Santorini (Thera) which is thought by some archaeologists...climate GEOARCHAEOLOGY 17 Figure 2 Sedgefield, County Durham. Fluxgate gradiometer data. 1 0.5 m. Romano...of these surveys, especially the 1802 survey of County Kilkenny by William Tighe (1766–1816), contain |
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