 | | Report (issue) | | No. 23 COLONY AND PROTECTORATE OF KENYA GEOLOGICAL SURVEY OF KENYA A GEOLOGICAL RECONNAISSANCE OF THE...of ancient rocks, extending between Meru, north-east of Mount Kenya, and Kitui. The quarter-degree areas...ultrabasic intrusives that are so prominent in the Embu-Meru area, and which it was anticipated would continue...Basement System, which are the oldest rocks known in Kenya. Apparently at present no economic significance...the Nyanzian or Kavirondian systems of Western Kenya, which have been valuable for the gold and silver |  | | Book | | in Commonwealth Countries United Kingdom Ghana Kenya Malawi Rhodesia Sierra Leone Tanzania Uganda Zambia...nepheline-bearing rocks in parts of Uganda and Kenya page 62 Figure 6 Nepheline-syenite occurrences...are crucial as transportation costs can quickly mount up to a prohibitive level. Although some dark-coloured...potassic lamellae. This intergrowth is termed perthite when the albite is subordinate in amount to the...slightly ‘undersaturated’ syenite is composed of perthite, soda-orthoclase or soda microcline, with alkali-pyroxenes |  | | Journal (article/letter/editorial) | | phase occurs at a number of localities, including Mount Velan in northwestern Piedmont, Lake Maggiore district...granite pegmatites found on the slopes of Mount Kenya in central Kenya and from the vicinity of Sultan Hamud... r71 RplnnuNcrs: Ho, T. L., The anorthoclase perthite from Chu-Chiatsien island near Putochan, Chekiang:...Range. These are complex with a rare earth phase on Mount Painter (Flinders Range), Radium Hill (near Olary)...mineral and beryllium phases at Mount Carbine. Both Bamford and Mount Carbine lie in the gold fields of |  | | 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 |  | | Book | | noted gemologist and geologist, Dr. Peter Keller. Kenya and Tanzania are revealed in their full mineralogical...of the 'Irelawney Collection of the Los Angeles County Museum of Natural History. ♦ Figures vii Foreword...Tanzania 32 Sapphire from Kenya 42 Ruby from Mangari, Tsavo West National Park, Kenya 44 Chapter 4. Emerald...Red Dravite Tourmaline from the Narok District, Kenya 99 Uvite-Dravite Chrome Tourmaline 99 Chapter 8...Appendix B. East African Gemstones in the Los Angeles County Museum of Natmal History Collections 138 Appendix |  | | Book | | carbonatitic-alkaline province outcropping on the Kenya-Uganda border which have recently received significant...Ring-Complexes ........................ . . .. 4.1 Mount Bana ..................................... 4.2 Nda......... 5.5 Mount Etinde ................. . . . . . . . . . . . . . . . . . .. 5.6 Mount Cameroon .....domain characterized East Africa from Madagascar and Kenya-Ethiopia to northeastern Sudan. It represents the...Popoff 1988a). Like the Atlantic Benue trough, the Kenya-Sudan Mesozoic trends could correspond to a failed |  | | Report (issue) | | 59 GOVERNMENT OF- KENYA MINISTRY OF NATURAL RESOURCES GEOLOGICAL SURYEY OF KENYA OF THE NORTH--MA€HÄKOS-l4EIIKA•...an area of about 1,200 square miles of central Kenya in the Central and Southern Provinces, about thirty...report covers the quarter degree sheet 52 N.W. (Kenya) (Directorate of Overseas Surveys sheet No. 149)...extent and lies partly in the Southern Province of Kenya, administered from Machakos, and partly in the Central...height from 4,000 feet to 7,000 feet. Throughout Kenya erosion bevels have been recorded on the Basement |  | VIJAYAKUMAR, K, FROST, C, FROST, B, CHAMBERLAIN, K (2007) The Chimakurti, Errakonda, and Uppalapadu plutons, Eastern Ghats Belt, India: An unusual association of tholeiitic and alkaline magmatism. Lithos, 97 (1) 30-57 doi:10.1016/j.lithos.2006.11.008 | Journal (article/letter/editorial) | | hypidiomorphic textures; local megacrysts of amphibole and perthite are present. The alkali feldspar is mostly mesoperthite...porphyritic and pegmatitic textures. The rock contains perthite and nepheline as essential minerals. Both subsolvus...the relative abundances of two feldspars in the perthite and antiperthite in backscattered electron images...Baker, B.H., 1987. Outline of the petrology of the Kenya Rift alkaline province. In: Fitton, J.G., Upton...Petrologic evolution of anorthoclase phonolite lavas at Mount Erebus, Ross Island, Antarctica. Journal of Petrology |  | | Book (edition) | | field work on the Iron Hill complex of Gunnison County, Colorado, in 1912-1913. Although his final results...1955), L. J. Fick and C. van der Heyde (1959). Kenya: B. H. Baker (1953), G. L. Coetzee and C...Tanganyika. b. In generally unaltered rocks: Ravalli County, Montana, and Verity, British Columbia. Similar...McCall (1959) estimates that at Rangwa in western Kenya the Precambrian surface was domed upward for 2000...and fenitization. Around Homa Mountain, western Kenya, Precambrian volcanic rocks are strongly shattered |  | | 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...It is bordered by paragneisses on one side and perthite-augen gneisses on the other and contains interbanded |  | Upadhyay, D., Raith, M.M., Mezger, K., Hammerschmidt, K. (2006) Mesoproterozoic rift-related alkaline magmatism at Elchuru, Prakasam Alkaline Province, SE India. Lithos, 89 (3) 447-477 doi:10.1016/j.lithos.2005.12.015 | Journal (article/letter/editorial) | | natrolite. Alkali feldspar is micro- to crypto-perthite and the host K-feldspar is microcline. Biotite...Ta anomalies as is seen for the Yamato syenites, Mount Collins monzonite (Zhao et al., 1995) and Priestley...like the Reunion syenites (Fisk et al., 1988), Kenya trachytes (Baker, 1987) and Victoria alkali basalts...Baker, B.H., 1987. Outline of the petrology of the Kenya Rift alkaline province. In: Fitton, J.G., Upton...phonolites and trachytes from the summit region of Mount Kenya. Contributions to Mineralogy and Petrology 89 |  | | Journal (issue) | | Western . . Kenya. By Thomas . . . . 150 REPORTS FROM THE GEOLOGICAL SURVErs Kenya • • • •...Processing Congress, 1960 Cl1emical Analysis of Kenya Kyanite • • • New Fertiliser Plant in Trinidad ... • • Kyanite-Pyrophyllite . • Eruption of Mount Cameroon in 1959 . in Finland Third Annual Report...• • • • The Geologyof Mfwanganu Island, Western Kenya . Plate I 1. 2. 3. Fig. I Fig. 2 Fig. 3 Fig...THE ISLAND, By OF MFWANGANU WESTERN THOMAS KENYA M.A., D.Phil. (Oxon.) WHITWORTH, Master of HatfieldCollegeand |  | | Book (edition) | | and sanidine 33. Photomicrograph of microcline-perthite, Hybla, Ontario. (Photomic. by E. 0. Rowland)...Rowland) 34. Formalized sections through microcline-perthite, parallel to (010) and (001) respectively 12 27...Block-diagram showing relation of vein- to film-perthite in cleavage 1nass of K,Na feldspar 36. Block-diagram...parallel to the a-axis. F!G. Or. o Anorthoclos (Kenya) {Mt. Erebu Ab. ~ ~ ~ ' - - - - ' - - , c , -...granites FIG. 33 Thin section of microcline-albite perthite, Hylba, Ontario. The original is a typical green |  | | Book | | parentcrystal is known as exsolution. Although the term perthite is specific to intergrowths of alkali feldspar...colour corresponding to Y. In all orientations of perthite the albite component has a higher birefringence...greatly. The large well-documented Osceola mudflow at Mount Rainier (Crandell and Mullineaux, 1967) travelled...Vesuvius after the eruption of A . D . 79, and that of Mount St. Helens after the eruption of 1980. Catastrophic...Crater Lake, Oregon, on the site of the ancestral Mount Mazama is a familiar example. Caldera formation |  | | Book | | Schlüter UNESCO Nairobi Office P.O. Box 30592 Nairobi Kenya ISBN 10 ISBN 13 3-540-29144-x Springer Berlin...Guinea Guinea-Bissau Ivory Coast / Cote dʼIvoire Kenya Lesotho Liberia Libya 32 38 42 46 50 52 56 60 64...VITTA, Nairobi, Kenya F. W. EDER, Paris, France (Directors) C. ETZOLD, Nairobi, Kenya (Director) M....Germany (Privatdozent) S. N. MOGERE, Nairobi, Kenya (Research Fellow) E. SILLMANN, Landau, Germany...Geological sketch map of the southern part of the Kenya Colony and the northern part of former German East |  | | Journal (article/letter/editorial) | | antiperthitic plagioclase, Montpelier anorthosite, Hanover County, Virginia. Virginia Journal of Science 34, 168...of the Montpelier andesine anorthosite, Hanover County, Virginia. Geological Society of America Abstracts...andesine anorthosite body near Montpelier, Hanover County, Virginia. Rocks and Minerals, 57–61. BOUDETTE...composition of anorthoclase and nepheline in Mount Kenya phonolite and Kilamanjaro trachyte, and crystalglass...L. (1983) A TEM and microprobe study of a two-perthite alkali gabbro: implications for the ternary feldspar |  | | Journal (article/letter/editorial) | | contain large albite, microcline, nepheline or perthite crystals with undulose extinction, commonly displaying...2E), which is represented by coarse grains of perthite, individual feldspars or nepheline mantled by...interstitial amphiboles. Large Pr feldspar and perthite crystals represent relict igneous textures (Fig...microcline and biotite, and al as flame-texture perthite intergrowths. Microcline occur as medium (1 -...nepheline grain boundary migration and pr localized perthite unmixing, indicating that at some point during |  | | Book (edition) | | contains the substance of albite intergrown as perthite, while even in those specimens which appear homogeneous...following types of perthite have fig. 33 Formalized sections through vein perthite (albite veins in microcline)...and figured: vein-perthite (probably the common¬ est), film-perthite, and braid-perthite in which the albite...intercalations are known as patch- and string-perthite which, on account of the lack of orientation,...Block-diagram showing relation of film- to vein-perthite in K-Na feldspar. intergrowth of microcline and | | | Book (edition) | | contains the substance of albite intergrown as perthite, while even in those specimens which appear homogeneous...mineral (Figs. 33 and 34). The following types of perthite have - ___--- ·~ . :::. , I, 'I I• - -·.·...- FIG. 33 Forn1alized sections through vein perthite (albite veins in microcline). Left, a (0 J0) section...and figured: vein-perthite (probably the co1nmonest), filn1-perthite, and braid-perthite in which the albite...intercalations are known as patch- and string-perthite which, on account of the lack of orientation, |  | | Book | | alkali feldspar, including orthoclase, microcline, perthite, anorthoclase, sanidine, and albitic plagioclase...fayalite plus quartz) and, in many of the rocks, perthite, mesoperthite or antiperthite (Streckeisen, 1974...charnockites is the presence of various types of perthite, this raises the common problem of how to distribute...distributed between A and P in the following way: Perthite — assign to A as the major component is alkali...albite. (Turner, 1896, p.728; Meadow Valley, Plumas County, 51 California, USA; Tröger 169; Johannsen v.3 |  | | Book | | or microcline. Micro- - Granitic rocks 19 perthite, which may be either orthoclase-microperthite...subsolvus ferrohastingsite granite with both micro¬ perthite and albite, and with transitions through ferrohastingsitebiotite...quartz and potash feldspar (normally microcline-perthite) with or without minor oligoclase, muscovite,...been described from parts of Africa, including Kenya where they are associated with others carrying riebeckite...rhyolites of the second period (PCretaceous) in the Mount Somers district, Canterbury, New Zealand, have phenocrysts |  | | Book (edition) | | The largest groups of new terms have been U.S. county names; rock-formation names (mostly North American);...Thesaurus. These include local geographic terms, U.S. county names, rock-formation names, and fossil names....term must be a name unique to one area. Lincoln County is not assigned coordinates in the Thesaurus, because...North America from the broader terms of Hanover County. There is no reciprocal entry for each broader...counties of the United States; e.g., Chautauqua County may have a broader term Kansas or New York. BX |  | | Book (edition) | | the total of 4,284 new Terms were United States county and city Terms. Counties and Cities in the United...States Earlier editions had Terms such as Washington County and Portland for counties and cities of the United...for example: Washington County Arkansas and Portland Maine. Each new county Term can now autopost its...to counties was a major task. The scope of U.S. county and city Terms can now be clear even when they...For example, whenever an in¬ dexer uses Atchison County Kansas the Terms Kan¬ sas, Midwest, and United |  | | Book (edition) | | Oceans and seas Greatest known height: Metres Mount Everest Average height 8863 840 Size and shape...latter rising to a maximum height of 8863 m in Mount Everest (Figure 2.6). The ocean floors, once thought...3.4 Sand dunes in the Colorado Desert, Imperial County, California. (W. C. Mendenhall, United States Geological...intergrowth of Ab- and Or-rich feldspar called perthite, visible under the micro¬ scope. Some perthites...cross-section through the Homa Mountain volcanic complex, Kenya. The complex developed through emplacement of carbonatite |  | | Book (volume) | | 1908, 207. Also in U.S.G.S., P.P. 99, 351. Park county, Montana. Jour. Geol., 74 A DESCRIPTIVE PETROGRAPHY...norites example .31. It from EHzabethtown, Essex County, in Osann's classification, gives the values ...characteristics observable microscopically. Microcline-perthite. Neubauer. Inter- growth of microcline and...the coast of Labrador. of E. Schweizerbart'sche perthite, after Perth, Verlagsbuchhandlung, Stuttgart...Miller: Geology of the North Creek quadrangle, Warren county, New York. Bull. N.Y. State Museum, No. 170, 1914 |
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