Metamorphic limestone

Table 5.44 Compositions (in weight %) of some natural amphiboles (from Deer et al., 1983) (1) = anthophyllite from a serpentinite (2) gedrite from a gedrite-kyanite-garnet paragenesis (3) cummingtonite from a oligoclase-biotite schist (4) common hornblende from a tonalite (5) pargasite from a metamorphic limestone (6) basaltic hornblende from a lathe (7) glaucophane from a glaucophane schist. ...

Marble is a highly crystalline metamorphic limestone which may be calcitic or dolomitic limestone. It occurs in many colours with veined and mottled effects. 

Metamorphic limestone is one in which the carbonate has completely re-crystal-lised. 

Calcium carbonate exists in three crystalline modifications (calcite, aragonite, vaterite), but only calcite has practical importance. It can be found in large quantities all over the world, but fillers mined at different locations differ considerably in purity, size of the crystals and origin, which all influence their use as fillers. In nature, it can be found in three different forms limestone, chalk and marble. Limestone is a consolidated sedimentary rock formed by the deposition of shells and skeletons of marine organisms, chalk is soft-textured limestone laid down in the cretaceous period and consists of nanofossils marble is metamorphic limestone formed under high pressures and temperatures. CaCOj occupies second place in usage behind talc in PP. 

Marble is a metamorphic, highly crystalline rock that may be high calcium or dolomitic limestone of varying purity. It occurs in virtually every color in diverse motded effects and is the most beautiful form of limestone. It is usually very hard and can be cut and poHshed to a very smooth surface. 

Barite [13462-86-7], natural barium sulfate, BaSO, commonly known as barytes, and sometimes as heavy spar, tiU, or cawk, occurs in many geological environments in sedimentary, igneous, and metamorphic rocks. Commercial deposits are of three types vein and cavity filling deposits residual deposits and bedded deposits. Most commercial sources are replacement deposits in limestone, dolomitic sandstone, and shales, or residual deposits caused by differential weathering that result in lumps of barite enclosed in clay. Barite is widely distributed and has minable deposits in many countries. 

Carbon dioxide gas can be useful in a variety of chemical experiments, too. The procedure for making carbon dioxide gas is essentially the same as it is for making hydrogen and hydrogen sulfide gases, except marble chips are used. Marble is a metamorphic rock that is created when limestone is placed under great pressure at high temperatures. Both limestone and marble are made up of calcium carbonate ... 

Limestone varieties differ greatly from one another in their texture and the impurities they contain, and consequently they also differ in color. The color of limestone may vary from white (when it contains practically no impurities) to off-white and even to intensely colored. Minor inclusions within the limestone structure are often of silica, usually in a concentration below 5%, as well as feldspar and clay in still lesser amounts. Many types of limestone also include embedded fossils. Much limestone deposits in the outer crust of the earth are altered during geologic metamorphic processes that involve mainly pressure and heat but also liquids and gases. Marble, for example, a metamorphic rock derived from calcium carbonate, is white when composed only of this substance colored metal ions and other impurities impart to marble a wide range of colors such as red, yellow, and green and also give... 

Zinc is the 24th most abundant element in the earth s crust. The Zn concentration in the lithosphere is 50-70 mg/kg (Vinogradoc, 1959 Adriano, 2001). Basic igneous rocks contain higher Zn (70-130 mg/kg) than metamorphic and sedimentary rocks (80 mg/kg). Carbonate and limestones contain low Zn (16-20 mg/kg) (Aubert and Pinta, 1977). The total Zn concentration in the soils of the world ranges from 10 to 300 mg/kg (Swaine, 1955), with average concentrations from 50 to 100 mg/kg (Aubert and Pinta, 1977). Arid and semi-arid soils vary from trace levels (subdesert soils) to 900 mg/kg (saline alkali soils) (Aubert and Pinta, 1977). The average Zn concentration in the arid and semi-arid soils of the U.S. (62.9 mg/kg) is... 

The geology of Cyprus is dominated by four distinct terranes - the Troodos Ophiolite Complex composed of mafic and ultramafic rocks, the Circum-Troodos Sedimentary Sequence containing calcarenites, siltstones and carbonates, the Mamonia Complex composed of igneous, sedimentary and metamorphic rocks and the Kyrenia Terrain containing a series of allochthonous massive and recrystallised limestones dolomites and marbles. These terranes generate highly varied landscapes (Fig 1). 

Concerning estimation of the activity of CO2 in the fluid phase, besides carbonate equilibria (discussed in some detail in section 8.10), equilibria in the CaO-Si02-C02 system are also important. In the medium-low metamorphism of limestones, the equilibrium... 

Non-metamorphic equivalents of this Th-free mineralization may be sought in some rare limestone-hosted U-occurences, such as the Jurassic Todilto lacustrine formation in the Grant Uranium Belt (Rawson Richard 1980), the Cretaceous Toolebuc marine formation in Eromanga Basin (Ramsden 1982), the Mesoproterozoic Vempale marine formation in Cuddapah Basin (Sinha et al. 1989), and the Cretaceous Probeer marine formation in the Huab deposit (Hartleb 1988). 

Total Carbohydrates. The results of the phenol-sulfuric acid tests for total carbohydrates are listed in Table 1. The Lower and Middle Ordovician dolomites and limestones of this area did not yield detectable total carbohydrates, either because they are absent or because of metamorphic degradation. Palacas (5) and Palacas, Swain, and Smith (6), on the other hand, found traces of glucose and other sugars in Lower and Middle Ordovician rocks of Franklin County, Pa. southeast of the Mt. Union area. It appears that the early and medial Ordovician seas of the Mt. Union area may neither have been receiving much carbohydrate material from the lands nor was much being contributed by organisms to the bottom sediments. 

Scapolite is found in the metamoiphic locks, particularly those, rich in calcium also in contact metamorphic deposits in limestones. It has been found in basic igneous rocks, probably as a secondary mineral. Notable localities are Lake Baikal, Siberia Arendal. Norway and Madagascar. In the United States, it is found in Massachusetts, New York, and New Jersey. Greenville, in the Province of Quebec, Canada is an important locality. Superb transparent yellow gem crystals have recently been found in Brazil and Tanzania. Wernente (scapolite) was named in honor of A.O. Werner, a famous German mineralogist (1749-1817). 

Zoisite occurs in crystalline schists which are products of regional metamorphism of basic igneous rocks rich in plagioclase, the calcium-nch feldspar also in argillaceous calcareous sandstones, thulite from quartz veins, pegmatites, and metamorphosed impure limestones and dolomites. 

Marble is a metamorphic rock made of calcium carbonate. It is formed when limestone is subjected to high pressures or high temperatures, or sometimes both acting together, to create crystals of calcium carbonate in the rock. 

In metamorphosed sedimentary rocks, arsenic tends to occur in oxide and sulfide minerals (Bebout et al., 1999), 69-70. Many metamorphic rocks simply inherit their arsenic from their precursor rocks. That is, unless arsenic-rich metamorphic fluids are introduced, quartzites metamorphosed from low-arsenic quartz-rich sandstones and marbles metamorphosed from low-arsenic limestones should have relatively little arsenic. In contrast, shales often contain more arsenic than sandstones and limestones (Table 3.23). Therefore, slates and phyllites that form from the metamorphism of shales should inherit at least some of the arsenic (Table 3.24). 

Elevated arsenic concentrations in oxic aquifers in Arizona (US) were linked to pH-dependent desorption (Robertson, 1989). Similar results exist for metamorphic aquifers in New England (US), where moderately alkaline waters (pH 7.5-9.3) were found to have elevated concentrations of arsenic (Robinson and Ayotte, 2006). Conversely, (BGS (British Geological Survey), 1989) suggested that arsenic concentrations of <4pgF-1 in water of the Lincolnshire Limestone (UK) cannot be explained by pH values of 7.0-9.5. McArthur et al. (2004) commented that the observations of pH increases with arsenic mobilization by Welch, Lico and Hughes (1988) and Robertson (1989) are not by themselves sufficient to prove that arsenic is mobilized by increasing pH. Arsenic may be mobilized by extended residence times, evaporation, and/or weathering, any of which could lead to both increases in pH and dissolved arsenic concentrations. 

Marble A metamorphic rock chiefly consisting of calcite (CaCCU). Marbles typically form from the metamorphism of limestones (compare with skarn). 

The Tuscan units consisting of Late Triassic to early Miocene sedimentary rocks (conglomerates, evaporites, limestones, marls and arenaceous flysch) overlying the metamorphic basement, and affected by Alpine metamorphism in some places (e.g. in the Alpi Apuane). 

Ma (Metrich 1985 Metrich et al. 1988) and consists of basalt, trachybasalt, shoshonite, latite and phonolite (Fig. 6.18). The Pontine Islands are formed entirely of volcanic rocks, except for Zannone, where the sedimentary and metamorphic basement (phyllites, quartzites and Mesozoic to Miocene limestones, dolostones, marls and siltstones) crops out. 

More extreme subterranean processes (especially heat) cause substantial changes in the sediments and lead to the formation of metamorphic rock. Thus, marble is heat metamorphosed limestone and slate is pressure metamorphosed shale. 

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