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Aragonite crusts

Poorly formed Mg-silicate platelets made up the acid-insoluble residue of aragonite crusts. XRD and EDX microanalysis of this material by Polyak and Guven (2000) suggested that it was kerolite or kerolite-like. Kerolite is a non-expandable hydrous phyllosilicate with a chemical composition and X-ray diffraction pattern similar to talc and stevensite (Brindley et ak, 1977). The clay fills spaces between aragonite needles in cave crusts. [Pg.307]

A priori considerations. An extensive review of the form and mineralogy of the secondary cave deposits is provided by Hill and Forti (1997), but also see Ford and Williams (1989). By far the most useful speleothems for geological purposes are the most common forms stalactites, stalagmites and flowstones composed of calcite, and occasionally aragonite. Other deposits that have been used to derive useful information include travertines, gypsum crusts, calcite veins and scalenohedral calcite (dog-tooth spar). [Pg.429]

According to Kelts and Shahrabi (1986), Lake Urmia in northwestern Iran, one of the larger saline lakes in the world, resembles Great Salt lake in morphology, water chemistry, and sediments. The carbonate precipitates are largely aragonite as fecal pellets, thin crusts, or oolites. [Pg.2667]

Barium is a member of the alkaline earth metals. The alkaline earth metals make up Group 2 (IIA) of the periodic table. The other elements in this group are beryllium, magnesium, calcium, strontium, and radium. These elements tend to be relatively active chemically and form a number of important and useful compounds. They also tend to occur abundantly in Earth s crust in a number of familiar minerals such as aragonite, calcite, chalk, limestone, marble, travertine, magnesite, and dolomite. Alkaline earth compounds are widely used as building materials. [Pg.43]

Mariana Trough is a back-arc spreading center that occurs between a remnant arc and the currently active Mariana arc. On the flanks of axial volcanoes in the central Mariana Trough are several vent fields with measured temperatures up to 287°C and sulfide-sulfate chimneys comprised of sphalerite, galena, and barite, due to metal sources from the underlying andesitic crust. An unusual occurrence in the northeast portion of the Mariana Arc is a serpentinite mud volcano called Conical Seamount. Carbonate (calcite, aragonite) and silicate (Mg silicate) chimneys occur near the mud volcano summit. Associated fluids are cold, sulfate-sulfide-carbonate-silica-rich, and have pHs as high as... [Pg.514]

Calcium carbonate (KAL-see-um CAR-bun-ate) is one of the most common compounds on Earth, making up about 7 percent of Earth s crust. It occurs in a number of minerals and other natural materials, including aragonite, calcite, chalk, limestone, marble, marl, oyster shells, pearls, and travertine. Stalactites and stalagmites found in caves are made primarily of calcium carbonate. As indicated by the melting points of aragonite and calcite, the compound s physical properties may differ somewhat depending on its crystal form. It typically occurs as an odorless, tasteless white powder or colorless crystals. [Pg.143]


See other pages where Aragonite crusts is mentioned: [Pg.303]    [Pg.308]    [Pg.303]    [Pg.308]    [Pg.297]    [Pg.11]    [Pg.401]    [Pg.501]    [Pg.509]    [Pg.539]    [Pg.502]    [Pg.59]    [Pg.61]    [Pg.3847]    [Pg.3848]    [Pg.304]    [Pg.305]    [Pg.308]    [Pg.372]    [Pg.382]    [Pg.248]    [Pg.192]    [Pg.449]    [Pg.285]    [Pg.152]   
See also in sourсe #XX -- [ Pg.303 , Pg.304 , Pg.305 , Pg.306 , Pg.307 , Pg.308 , Pg.309 , Pg.310 ]




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Aragonite

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