 | | Journal (article/letter/editorial) | | isotope chemistry of gaylussite and nahcolite from the deposits of the crater lake at Malha, northern Sudan...April 1997; accepted 21 November 1997 Abstract Gaylussite ŽNa 2 CO 3 P CaCO 3 P 5H 2 O. and nahcolite ŽNaHCO...ŽNaHCO 3 . in deposits of the crater lake at Malha are predictably characterized by a strong 18 O enrichment...yield high d 13 C values, which, in the case of gaylussite, are covariant with the d 18 O values. The fact...pertains both to the synsedimentary and pedogenic gaylussite deposits of the Malha basin demonstrates that |  | | Journal (article/letter/editorial) | | lakes exist on all continents except E urope. Saline lake deposits, however, are usually restricted and ephemeral...the Green River Formation of Wyoming and Searles Lake of California being the exceptions. This neglect...rivers are the Great Salt l,ake of Utah, Lake Chad of Central Africa, the Dead Sea, the Caspian Sea, and many...mud flat; 4. saline mud flat; 5. perennial salt lake; 6. ephemeral salt pan; 7. perennial stream flood...are charac terized by saline minerals, such as gaylussite (Na2C03 ' CaC03 ' 5HzO), gypsum (CaS04' 2HzO) |  | | Journal (article/letter/editorial) | | Britain Brines and evaporites of the Lake Chad basin, Africa HANS P. EUGSTER Department of Earth and...continent and on the southern edge of the Sahara, Lake Chad has many peculiar and interesting features very...great lakes of tropical Africa.” (BEADLE, 1974, The Inland Waters of Tropical Africa, p. 160). A&met-The...A&met-The waters of Lake Chad in Central Africa are dilute and of the Ca-Mg-Na-HCO, type with low Cl and S04.... In the Kanem region, NE of Lake Chad, such waters are subjected to evaporative concentration and brines |  | | Journal (article/letter/editorial) | | (NaHCO3 · Na2CO3 · 2H 2O), nahcolite (NaHCO3), gaylussite (Na2CO3 · CaCO 3 · 5H 2O), thermonatrite (Na2CO3...Searles Lake of Pleistocene age in California in the U.S.A. (Eugster & Smith 1965) and Lake Magadi of...of Pleistocene age to Recent in East Africa (Bradley & Eugster 1969). Natron minerals are formed within...such as thermonatrite, nahcolite, pirrsonite, gaylussite, shortite, had been occurred within the same...0.18 – 0.3 0.26 rite + natron + pirrsonite + gaylussite paragenesis were determined by the detailed mineralogical |  | | Report (issue) | | c = 4.956(1) Z=4 X-ray Powder Pattern: Andjia, Chad. 10.33 (10), 4.014 (10), 3.435 (9), 2.480 (8), 3...57.5 0.5 13.2 1.2 27.5 99.63 99.9 (1) Andjia, Chad; corresponding to (Na0:93 K0:07 )§=1:00 H1:03 (Si2:06...(Si2:06 Al0:01 )§=2:07 O4:13 (OH)2:04 ² 1:97H2 O: (2) Lake Bogoria, Kenya; by AA, H2 O by TGA. Occurrence:...depression (Andjia, Chad). Association: Kenya). Gaylussite, trona (Andjia, Chad); magadiite, analcime...mordenite (Lake Bogoria, Distribution: Kenya. In the Kanem region, near Andjia, Chad. From Lake Bogoria |  | | Journal (article/letter/editorial) | | TARDY 4 ' Centre O.R.S.T.O.M. N'Djamena, N'Djamena (Chad) 2S.G.A.L. and B.R.G.M., Strasbourg (France) 3Institut...evaporation of waters in Chad. Chem. Geol., 19: 215--228. In the Lake Chad system, most of the strongly...geochemical balance of Mg in the Lake Chad system is discussed. INTRODUCTION Lake Chad is l o c a t e d in a closed...o p i c a l climate into t h e lake. In t h e n o r t h , t h e lake is limited b y a fossil erg, f o...o r a t i o n . T h e waters flowing into t h e lake c o n t a i n less t h a n 100 mg/1 o f dissolved |  | | Report (issue) | | 15 99.90 100.00 37.39 14.25 3.22 (1) Searles Lake, California, USA; average of two analyses. (2) John...pirssonite (Searles Lake, California, USA); shortite, trona, pirssonite, gaylussite, labuntsovite, searlesite...Distribution: In the USA, from Searles Lake, San Bernardino Co., and Borax Lake, Lake Co., California; in the John...Wyoming. At Lake Katwe and Lake Mahega, Uganda. In the Kanem region, near Lake Chad, Chad. From the Tuzla...Island, Ross Sea, Antarctica. From the Zabuye Salt Lake, Nagri, Tibet, China. Name: To honor Charles H. |  | | Journal (article/letter/editorial) | | (Geochemistry of the waters and salts in the soils of the Lake Chad polders: Application of a thermodynamic model...to the evolution of soils of the northeastern Lake Chad system. Influences of oxido-reduction and conditions... tels que le gypse, l'halite, le trona et la gaylussite. Les sels trouv6s ~ la surface des s6diments...polders: calcite faiblement magn~sienne (2--4%), gaylussite et trona. Les r6sultats obtenus par calcul et...d6posent en surface et successivement la calcite, la gaylussite et le trona. Les eaux initiales sont bicarbonat~es |  | | Journal (article/letter/editorial) | | source water contrasts with closed-basin saline lake complexes, where surface water from the adjacent...system. The principle geochemical process controlling lake chemistry is evaporative concentration. Other processes...required to be evaporated to produce the observed lake compositions. These differences are related to the...processes? (4) What are the implications of the lake geochemistry relative to the hydrology of the lakes...lakes of the Lake Chad basin, Africa ( EUGSTER and MAGLIONI,1979); and Deep Springs Lake, California (JONES |  | | Journal (article/letter/editorial) | | Andija, Kanem region, northeastern edge of Lake Chad, Africa. The name is for the region. Type material...pale yellow. Fluoresces 1.5-2mm, associatedwith gaylussite,in massesof trona in weakly in U.V. yellow-green...of the barite-polymetallicdepositof Kairakty' central Kazakhstan. lzuesl. Akad. Nauk Kazakh' S.S.R.,...mineral occurs in aggregatesat the Kairakty deposit, central Kazakhstan. It is coated by phosgenite,which was |  | | Journal (article/letter/editorial) | | CLAY MINERAL DIAGENESIS IN CORE K_M-3 OF SEARLES LAKE, CALIFORNIA R. L. H A Y , l S. G . G U L D M A N...Saskatoon, Canada S7N 0W0 Abstract--Core KM-3 at Searles Lake, California, comprises 693.4 m of lacustrine sediments...sediments deposited over the past 3.2 m.y. The lake water evolved from moderately saline, slightly alkaline...principal detrital clay minerals supplied to Searles Lake at present and probably during the late Pliocene...pH ( - 7 . 5 - 8 . 0 ) are inferred for both the lake and pore water of the lower zone. Oxygen-isotope |  | Schmidmair, Daniela, Kahlenberg, Volker, Többens, Daniel M., Schottenberger, Herwig, Jochem De Wit, , Griesser, Ulrich J. (2015) Temperature- and moisture-dependent powder X-ray diffraction studies of kanemite (NaSi2O4(OH)·3H2O) Mineralogical Magazine, 79 (1) 103-120 doi:10.1180/minmag.2015.079.1.09 | Journal (article/letter/editorial) | | at the northeastern bank of Lake Chad, Republic of Chad, Central Africa. However, kanemite has also been...been found in the recent evaporites of Lake Bogoria, Kenya (Perinet et al., 1982), in miarolitic cavities...sodiumcontaining minerals including carbonates (e.g. gaylussite, nahcolite, trona, thermonatrite, soda or natrite)...of a peak were considered to contribute to the central reflection. Thompson-Cox-Hastings pseudo-Voigt functions...kanemite is located in the Sahel region of sub-Saharan Africa it may be only a question of time until a natural |  | Sahajpal, Rahul, Zimmerman, Susan R.H., Datta, Saugata, Hemming, N. Gary, Hemming, Sidney R. (2011) Assessing Li and other leachable geochemical proxies for paleo-salinity in lake sediments from the Mono Basin, CA (USA) Geochimica et Cosmochimica Acta, 75 (24) 7855-7863 doi:10.1016/j.gca.2011.10.001 | Journal (article/letter/editorial) | | leachable geochemical proxies for paleo-salinity in lake sediments from the Mono Basin, CA (USA) Rahul Sahajpal...Ca and Sr, as geochemical proxies of salinity in lake sediments in the Mono Basin, California. All the...paleo-lake level estimates based on physical and stratigraphic evidence. The CaCO3 content of lake sediments...reliable proxy for lake level changes in the Mono basin and the adjoining Owens Lake basin, corresponds...paleo-hydrology. Mono Lake is one of many Great Basin lakes that experienced significant lake level fluctuations |  | | Report (issue) | | 2015-1092 of Li m n og Cover: Photograph of Lake Tahoe looking west to California from Sand Harbor... Preface Limnogeology is the study of modern lakes and lake deposits in the geologic record. Limnogeologists...prevalent in the early 1990s when it became clear that lake deposits contain continental environmental and climate...with scientists from Europe, South America, Asia, Africa, Australia, and New Zealand. The format of the...showed the breadth of research that is being done in lake systems worldwide. The abstracts of the keynote |  | | Book | | smectites in intermediate to high latitudes (Massif Central/France, Iceland). These minerals result from the...magnesian clays accompanied by salts as in the Lake Chad basin, a process referred to as salinolysis. When...] 0.5 0.3 0.1 15 % ] 10 5 Ii I i~ C ESE AFRICA 15 % 10 5 o rm/lOS. RECENT Fig. 1.5. Terrigenous...intertidal and supratidal zones, in marshes and along lake shores in certain low-latitude regions such as the...have a higher capacity for dissolution than the central zones. The identification of the various modifications |  | | Book | | dtoevol0000unse BACKGROUND TO EVOLUTION IN AFRICA ''Systematic Investigation of the African Later...RESEARCH, NEW YORK BACKGROUND TO EVOLUTION IN AFRICA Edited by WALTER W. BISHOP and J. DESMOND CLARK...Pleistocene of East Africa L. S. B. Leakey 31 The later T ertiary in East Africa-volcanics, sedi1nents...the Pleistocene of southern Africa L. H. Wells The fossil I-Iyaenids of Africa-a reappraisal R. F. Ewer...the basis of vegetation changes in sub-Saharan Africa E . M. van Zinderen Bakker 0 149 Faunal fluctuations |  | | Book | | To ,ny children Kieren, Matthe11 ·. and Tristan Lake Fro,ne, South Australia Air arched, enonnous, lining...and the "Messi11ia11 Salinity Crisis". J 14 Ferry Lake Anhydrite, Fairway Field, East Texas, 121 Jurassic...Modern Deep-water Evaporites 138 Dead Sea. 138 Lake Lisan (a Dead Sea precursor), 146 Ancient Deep...have been fought to possess salt lakes in America, Africa and the Middle East. History of Evaporite Research...evaporitic sedimentation in areas as widespread as Africa, Antarctica, Australia, the Middle East, and the |  | | Book | | similar ones are retained in numerous entries. Such Central and Eastern Europe regional names as Bavaria, Bohemia...first time; demonstrated that diamond is carbon. gaylussite, Joseph Louis Gay-Lussac (1778-1850), French...Colonel Hendrik von Prehn, of Cape Town, South Africa. samarskite, Colonel V. E. von Samarski-Bykhovets... antarctite, Antarctic Continent, athabascaite, Lake Athabasca, Canada, bityite, Mt. Bity, Madagascar...gamagarite, Gamagara ridge, Postmasburg district, South Africa. garronite, Garron plateau area of Antrim, Ireland |  | | Book | | 2 Domes Area, Northeast Pacific. . 267 12.2.3 Central South-Equatorial Pacific . 270 12.2.4 Nazca Plate...season and by rather sparse vegetation, as in West Africa, the leaching horizon is submitted to intense erosion...soil development and morphological evolution, West Africa. (After Millot 1982). Dl discordance of the weathering...Weathering complexes and young soils studied in Central Norway contain essentially fragmented micas and...world soils. (After Gradusov 1974) the Massif Central, France (Dejou et al. 1968, Maurel 1968) and on |  | | Book | | sabkhas.181 Contents Alluvial fan-ephemeral saline lake.] 81 Sabkha Yotvata, Israel.181 Basin and Range...field-ephemeral saline lake.201 Lake Eyre, Australia.202 Lake Frome, Australia.208 Lake Callabonna, Australia...210 Perennial stream floodplain-perennial saline lake.210 Eolian sabkhas. 211 Sea-margins with elongate...230 Coastal salinas of the Middle East.231 Solar Lake. Gulf of Elat.231 Ras Muhammad Pool, Southern Sinai...saline lakes.238 Great Salt Lake, Utah.239 Mono Lake, California.243 Lake levels and conditions.244 Tufa |  | | Book | | Prehistoric artists from the San people of South Africa to the ancient Egyptians ground rocky soil to produce...it is just 20km/12 miles beneath California's Central Valley, it is 90k1n/54 miles thick under the Himalayas...noticed the extraordinary way the west coast of Africa mirrored the east coast of South America. H e also...clay. As a river washes into the sea, or into a lake, the heaviest quartz grains are dropped nearest...volcanic rock, such as the ki,nberlites of South Africa and the lamproites of Australia. Above: Diamonds |  | | Book | | . . . . .. 2.5 Lake Sediments .................................. 2.5.1 Different Lake Systems and Their...Ancient Examples of Lake Sediments .... 2.5.3 Specific Features of Lakes and Lake Sediments ...... 3 Coastal...forming the boundaries of the depositional area or a central rift zone may be absent. Subsidence occurs predominantly...oceanic sediments, but it does imply that the central basin floor lies at least 2 to 3 km below sea level...Morphology 11 a POST ·DEPOSITIONAL BASIN ERODED LAKE SEDIMENT --- ..... ( LITTLE LATERAL CHANGE IN |  | | Book | | Geological Science, University of Cape Town, South Africa; 65 & 127, Ian Coulson, University of Regina, Canada...it is just 20km/12 miles beneath California’s Central Valley, it is substances like zinc and lead that...west coast of process is when movement of the Africa mirrored the east coast of South Making continents...ancient rock. These grains behaved like through a central rift, pushing the tiny compasses, lining up with...happened the mid-ocean ridge that forms where when Africa and North America plates are moving apart under |  | | Book (edition) | | well balanced selection of mineral localities was central to the authors' effort. We took into consideration...repeated changes of administrative divisions in central and eastern Europe during the last 60 years are...South America and Greenland, then Europe, Asia, Africa, Australia, and Antarctica), then those of pegmatitic...Pb-Zn ore deposits or fluorite deposits of the central United States or of the Upper Silesian historical...California, in fine crystals in talc near Wenatchee Lake, Chelan co., Washington, also at Sulzer, Prince |  | | Report (volume) | | 13 Seasonal diagenetic changes in salts of Owens Lake, California, 1970-77, by George I. Smith and Irving...237· Diagenesis of the Morrison Formation, Smith Lake uranium district, McKinley County, New Mexico, by... P. A., 1975, New interpretations of Great Salt Lake ooids and of ancient nonskeletal carbonate mineralogy:... Seasonal Diagenetic Changes in Salts of Owens Lake, California, 1970-77 By GEORGE I. SMITH, U.S. Geological...'!I 1. Map showing location of Owens Lake and positions of lake shorelines February 1913, August 1969 |
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Lake Chad, Central Africa