 | | Report (chapter) | | springs may be sub-lacustrine, or may occur along lake shores. In the lacustrine environment, stromatolites...isotopic dating; determining altitudes of former lake levels; and providing evidence for hydrological...studies of the Quaternary stromatolites of this region. The majority of the stromatolite occurrences that...placed on the stromatolites' relationship to former lake levels (Grove & Goudie 1971; Gasse & Rognon 1973;...from the PlioPleistocene deposits of northeastern Lake Turkana (Johnson 1974; Johnson & Raynolds 1976) |  | | Journal (article/letter/editorial) | | composition of the brine and evaporite deposits at Lake Katwe suggest that the salinity of this and the...in places, notably to the north of Lake Albert and southeast of Lake Edward, the edge of the Rift is marked...Granitic gneisses outcrop over more than 60% of the region under consideration (Fig. 2). They outcrop extensively...while in the central and southern parts of the region they occur within the area of outcrop of the Buganda-Toro...Investigations 1170 A. ARAD \ and IV. H. TANZANIA ‘< MORTON (fl Fig. 1. East Africa showing |  | | Journal (article/letter/editorial) | | bulk isotopiccomposition of inflow waters to the lake. Suitesof carbonateswhich display covatying 613Cand...However, other types of carbonate are often present in lake sediments; it is thus not an absenceof suitable...problems this causes in interpreting isotopic data from lake carbonates (see also Cerling et al, 1988). No two...comprise the dominant component of the sediment (lake marl, “Seekreide”, mitrite, of various authors)...oscillate between calcite, high-Mg calcite or aragonite precipitation, depending upon salinity (Miiller |  | | Report (volume) | | Chad, Ethiopia, Kenya, Malawi, Nigeria, Sudan, Tanzania and Uganda. However, in the last few years there...more research has been conducted in the Lake Tanganyika and Lake Malawi sectors of East Africa and in the...Structural expressions of rifting: lessons from Lake Tanganyika, Africa.29 Baker, B.FL Tectonics and...in the Kenya Rift from the equator northwards to Lake Turkana ... 59 Swain, C.J., Skinner, N.J. & Khan...Depth to metamorphic basement in the Koobi Fora region from seismic and gravity data. 75 Watkins, R.T |  | | Report (issue) | | tuffs (Olduvai Gorge, Tanzania). Association: Fluorite, calcite, dolomite, aragonite, pyrite, quartz (Quebec...Peninsula, Russia. From near Lake Natron, in the Olduvai Gorge area, Tanzania. From east of Tenès, Algeria |  | Owen, Richard Alastair, Owen, Richard Bernhart, Renaut, Robin W., Scott, Jennifer J., Jones, Brian, Ashley, Gail M. (2008) Mineralogy and origin of rhizoliths on the margins of saline, alkaline Lake Bogoria, Kenya Rift Valley. Sedimentary Geology, 203 (1) 143-163 doi:10.1016/j.sedgeo.2007.11.007 | Journal (article/letter/editorial) | | of rhizoliths on the margins of saline, alkaline Lake Bogoria, Kenya Rift Valley Richard Alastair Owen...range of rhizoliths occurs around the margins of Lake Bogoria, Kenya. These include root casts, moulds...Rhizoliths; Silica; Fluorite; Calcite; Zeolite; Lake Bogoria 1. Introduction Fossilised roots and root...preserved in the marginal sediments of Lake Bogoria, a saline, alkaline lake partly fed by hot springs in the...this term in their studies of fossil roots in the Lake Turkana basin of northern Kenya, and the terminology |  | | Journal (article/letter/editorial) | | transformation of Oldoinyo Lengai natrocarbonatites, Tanzania Anatoly N. Zaitsev a,b,c,⁎, Jörg Keller c a Department...the Oldoinyo Lengai volcano, East African Rift, Tanzania, consist of the water-soluble phenocryst minerals...presence of the minerals natrite, nahcolite or natron. The secondary minerals formed during the first...saline lakes, e.g., modern Lake Magadi, Lake Natron or the 1.9– 1.7 Ma Lake Olduvai (e.g., Monnin and...southern shore of Lake Natron shows the presence of trona, halite, anhydrite, natron and gaylussite. Several |  | | Book | | MARINE ENVIRONMENTS The Modern Thrornbolites of Lake Clifton, Western Australia L. S. Moore and R. V...related to increasing salinity of the environment. Aragonite precipitated within the ix x primary porosity...Marine Environments THE MODERN THROMBOLITES OF LAKE CLIFTON, WESTERN AUSTRALIA L.S. MOOREI and R.V....microbialites are presently forming in Lake Clifton, a marine-derived coastal lake in southwestern Australia. The...far the most predominant form of microbialite in Lake Clifton, with small stromatolites restricted to |  | | 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...perennial rivers are the Great Salt l,ake of Utah, Lake Chad of Central Africa, the Dead Sea, the Caspian...mud flat; 4. saline mud flat; 5. perennial salt lake; 6. ephemeral salt pan; 7. perennial stream flood...the basin is occupied either by a perennial salt lake of by an ephemeral salt pan. A perennial river is |  | | Report (chapter) | | Since XRD analyses indicate the presence of aragonite, these bushes of needles are probably aragonitic...(EPS), SEM image. (e) Aragonite crystals (XRD analyses indicate 1% of aragonite in sample analysed), SEM...SEM image. (f) Aragonite needles partially recrystallized into calcite, SEM image. (a, c, d) reproduced...dominant calcitic mineralogy 98.91% with 1.09% of aragonite preserved, and traces of dolomite and quartz....luminescent early diagenetic calcite cements replaces aragonite needles, surrounds clots and fills hairline fractures |  | | Book | | Carbonatites - Tanzania - Oldoinyo Lengai Region - Congresses. ism - Tanzania - Oldoinyo Lengai Region - Congresses...Congresses. 3. Oldoinyo Lengai (Tanzania) I. Bell, Keith, 1938- . II. Keller, J. (J6rg), 1938III. Series...African rift in northern Tanzania near the Kenya-Tanzania border, south of Lake Natron, and was considered...African Rift Valley System, particularly in Lake Natron, that lies close to Oldoinyo Lengai. However...of the Neogene-Quaternary volcanoes in northern Tanzania (Fig. 1). It is one of a group of nephelinite |  | | Report (issue) | | Industrial minerals and rocks of the tri-state border region— West Texas, southern New Mexico, and northern...Abstract—Industrial minerals and rocks in the tri-state border region are located in a variety of geologic environments...Ciudad Juarez, whose market stretches throughout the region and beyond. Other construction materials include...Adobe buildings are still common throughout the region, in contrast to the soft, Tertiary volcanic tuff...importance. Included here is potash of the Carlsbad district of southeastern New Mexico and Frasch sulfur production |  | | Journal (article/letter/editorial) | | However, alkaline soda lakes are rare in this region. Most lake brines are of the Na-Cl and Na-Cl-(Sod) types...volcanic activity which filled the intervening region between the two Cordilleras. Volcanoes (which now...low level or desiccated. The most recent pluvial lake left two extensive salt crusts in the central depression...surface or just above, producing a very shallow lake of irregular shape. Lacustrine sediments are not...balance of a closed basin containing a permanent lake ( HUTCHINSON, 1957; LANGBEIN, 196 1) : V=SXE into |  | | Report (volume) | | 13 Seasonal diagenetic changes in salts of Owens Lake, California, 1970-77, by George I. Smith and Irving...dissolution and crystal growth kinetics of calcite and aragonite, by Eurybiades Busenberg and L. Niel Plummer 139...Diagenesis of the Morrison Formation, Smith Lake uranium district, McKinley County, New Mexico, by NeilS....Member of the Morrison Formation, Grants uranium region, northwestern New Mexico, by Paula L. Hansley 265...many species of organisms that today secrete aragonite or high-magnesium calcite may have secreted nearly |  | Hazen, Robert M., Hummer, Daniel R., Hystad, Grethe, Downs, Robert T., Golden, Joshua J. (2016) Carbon mineral ecology: Predicting the undiscovered minerals of carbon. American Mineralogist, 101 (4) 889-906 doi:10.2138/am-2016-5546 | Journal (article/letter/editorial) | | localities), cerussite (PbCO3; 4658 localities), aragonite (CaCO3; 2895 localities), ankerite [FeMg(CO3)2;...wegscheiderite [Na5H3(CO3)4] thermonatrite [Na2(CO3)∙H2O] natron [Na2(CO3)∙10H2O] pirssonite [Na2Ca(CO3)2∙2H2O]...amplified in the following sections. Calcite and aragonite groups. Numerous phases with the general formula... Ca, Mn, Fe, Co, Ni, Zn, Cd) or orthorhombic aragonite (A2+ = Ca, Sr, Ba, Pb) structures. These important...although Sr and Ba typically enter the orthorhombic aragonite structure rather than the rhombohedral dolomite |  | | 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 | | 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...loewite magnesian calcite mirabi lite nahcolite natron pentahydri te pirssonite poly halite rinneite sanderite...first mineral to precipitate is CaC03 usually as aragonite; this begins when the solution reaches twice the |  | | Journal (article/letter/editorial) | | magmatism formation: An example from the Georgetown region of Northeastern Australia .......................of pH in phosphate inhibition of calcite and aragonite precipitation seawater . . . . . . . . . . . ...origin of groundwater in a mafic pluton, EastBull Lake,Ontario,Canada . . . . . . . . . . . . . . . . ...boiling, and fluid mixing in the Keno Hill Ag-Pb-Zn district, Yukon Territory, Canada 1045 R. FENG and R...inclusions in halite: Modeling and application to Searles Lake, California 2059 D. E. CROWE, J. W. VALLEY,and |  | | Journal (issue) | | semi-arid alluvial basin, perhaps like parts of the Lake Eyre Basin in modern Australia. Back cover: (clockwise...found elsewhere, light soon begins to dawn on the district, and the structure of the whole becomes more or...trace fossil assemblages of the Warwick-Kenilworth district (Walker, 1969; Paton, 1974, 1975; Benton & Spencer...quartzite clasts appear to be derived mainly from the region of the Armorican massif (Brittany-Cornwall), by...the southern end of the horst, in the Warwick district, the Bromsgrove Sandstone rests unconformably |  | | Report (chapter) | | signature but also by some comparable features. Lake margin bioherms form continuous belts for hundreds...hydrothermal, karstic freshwater and evaporative lake carbonates. Carbonate precipitation results from...settings excludes lake marls, lake reefs (e.g. biogenic/ abiotic bioherms and mounds at lake margins) and...and hydrothermal spring-derived water mixing with lake water, or in evaporative lakes where water is ambient...carbonates precipitated from thermal waters at the saline lake water –spring interface, whereas precipitates within |  | | Journal (article/letter/editorial) | | magmatism formation: An example from the Georgetown region of Northeastern Australia .......................of pH in phosphate inhibition of calcite and aragonite precipitation rates in seawater . . . . . . ....origin of groundwater in a mafic pluton, East Bull Lake,Omario,Canada . . . . . . . . . . . . . . . . ....boiling, and fluid mixing in the Keno Hill Ag-Pb-Zn district, Yukon Territory, Canada . 1045 R. FJZNG and...inclusions in hatite: Modeling and application to Searles Lake, California 2059 D. E. CROWE, J. W. VALLEY,and |  | | Journal (issue) | | Pleistocene spring-fed wetlands in Ngorongoro Crater and Oldupai Gorge, Tanzania . . . . . . . Daniel M. Deocampo...HA \VLEY U.S. Depaitment of Commerce. NOAL. Great Lake,. En\.ironmental Rc-.earch Lahorator). Ann Arbor...Natural Sciem.:e, Complex Bu!falo. NY 14260-3050 Gn,at Lake, DR MARK T. HARRIS Univen.1ty or \Vi,con,m Depanment...-"' 106 •There are no a,soc1a~ ed1111r- lor the region., E. Eur A,ia. or S Amer. JotR'IAL o~ Sro1,1nffARY...PLEISTOCENE SPRING-FED WETLANDS IN NGORONGORO CRATER AND OLDUPAI* GORGE, TANZANIA DANIEL M. DEOCAMPO ,,o GAIL |  | | Book | | ohne Abgabe oder Aufnahme von Stoffen); e.g., aragonite altered to calcite. b. Alteration with the loss...of all components; e.g., native copper after aragonite 4. Perimorphs; e.g., quartz after calcite. What...(dimorphous) state to another; e.g., change of aragonite to calcite or beta quartz to alpha quartz. 5....1998). b. Replacement; e.g., native copper after aragonite from Corocoro, Bolivia. 6. Encrustation pseudomorphs...INTRODUCTION 11 The experimental replacement of aragonite by calcite under hydrothermal conditions between |  | | Book | | shoals adjacent to the Chari delta feeding into Lake Chad seem to relate directly to rubified (reddened)...precipitation and diagenesis in the sediments of the Lake Bogoria basin, Kenya Rift Valley. In Sedimentation...results in the coarser material in the lower head region of the flow moving relatively faster than the material...of the Lake District, are very well known. They rise to a height of about 450m above the lake in one...examples are well developed in Wales, in the Lake District, and in Scotland. Torrential gravels are also |  | | Book (edition) | | shoals adjacent to the Chari delta feeding into Lake Chad seem to relate directly to rubified (reddened)...precipitation and diagenesis in the sediments of the Lake Bogoria basin, Kenya Rift Valley. In Sedimentation...results in the coarser material in the lower head region of the flow moving relatively faster than the material...of the Lake District, are very well known. They rise to a height of about 450m above the lake in one...examples are well developed in Wales, in the Lake District, and in Scotland. Torrential gravels are also |
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