Dolomite filled

Fig. 10. Hand specimen, photograph and simplified drawings of a complex dolomite-cemented fracture, illustrating the adopted terminology and the mutual relationships of CSBs, intergranular dolomite cement (pale grey) and subsequent dolomite-filled dilatational veins (dark grey-black). The graph shows the lateral variation of point-counted intergranular dolomite cement and porosity from the centre to the margin of the fracture.

The finely crystalline dolomite filling dilatational central veins is slightly less ferroan than the surrounding intergranular spar (5-9 mol% FeCOj) (Fig. 11), and dull red to red-brown luminescent. Crystals are mostly less than 10 xm in size and predominantly planar-s. Multiple-stage vein fills are... 

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. 

Perl-mutterpapier, n, naereous paper, -rohr, n, -rohre, /. bead tube (tube filled with glass beads), -sago, m. pearl sago, -salz, n. micro-eosmic salt, -samen, m. seed pearl, -schicht, /. nacreous layer, -schnur, /. string of beads or pearls row of droplets, -seide, /. embroidery silk ardassine, -spat, m, pearl spar (pearly dolomite), -stein, m, perlite adu-laria. -sucht, /. bovine tubereulosis. -weisa, n. pearl white. 

The injection well was cased to a depth of about 1495 m (4900 ft) and extended into dolomite to a total depth of 1617 m (5300 ft). Injection began in the early 1960s and averaged around 340 L/min (90 gal/min). The natural fluid level was 60 m (200 ft) below the wellhead, and wastes were injected using gravity flow that is, the pressure head of the well when filled to the surface with fluid was sufficient to inject fluids without pumping under pressure.181... 

The fault-fill mineralization includes quartz, dolomite, ankerite, siderite, calcite, molybdenite, pyrrhotite, arsenopyrite, pyrite, chalcopyrite, sphalerite, galena, selenian galena, marcasite, ilmenite, and rutile (Maanijou 2007). 

The basal conglomerate unit shows high and variable copper concentrations (142 ppm to >5,000 ppm). The high concentrations are due to the presence of copper oxides in fractures filling spaces between clasts. Copper oxides are observed where white, mineralised dolomite overlies the conglomerate. 

Carbonate cement content in the studied rocks varies from 0 to 45 vol. %, mostly forming the pore filling. The following carbonates were observed (Koztowska 2004) siderite, Fe-dolomite, ankerite and Fe-calcite. The term siderite corresponds to minerals from the isomorphic group FeCOs-MgCOs with 60-100 mol percent FeCOs. Most siderites fall into the interval siderite - sideroplesite (Fig. 3). 

Carbon pitch is used for carbon electrodes in electrolytic reduction processes, such as aluminum reduction or the production of electro-steels in arc furnaces. Refractory pitch is used in the manufacture of refractory brick, usually burned magnesite or dolomite, the pores of which are filled with pitch by hot impregnation. Upon firing, the pitch in the brick is converted to carbon by carbonization. The remaining pitch coke within the refractory product retards penetration of molten metals and slags, thus prolonging the life of the brick furnace lining. Coke pitch is used in the production of foundry cores. 

Figure 10.30. Phanerozoic sedimentary rock mass-age relationships expressed as the logarithm of the survival rate in tons y-1 versus time. The straight lines are best fits to the total mass data (solid line) and to the carbonate mass data (dash-dot line) for particular intervals of Phanerozoic time. The difference between the logarithm of S for the carbonate mass and that of the dolomite mass is the survival rate of the calcite mass. Filled star is present total riverine flux to the oceans, whereas open star is carbonate flux.

Figure 4. Pyrite filling vuggy porosity in core S-35 in the U.S. midcontinent. See Fig. 3 for the location of this core. Pyrite (bright phase) occurs as both intergrowths and intergrowths with hydrothermal dolomite. Both are growing into a void in the rock.

Salt casts and molds, in the form of cubic and hopper-shaped voids, impressions, and fillings in rocks, are evidence of the former presence of salt in the rock. These features are fairly common in each of the study areas and are best seen in the dolomite beds that are capable of retaining the delicate impressions of the salt crystals. The quantity of salt removed from such casts and molds is small in comparison to that which can be removed from bedded rock salt. 

Unlike calcite and dolomite, siderite rarely forms as an extensive pore-filling cement, but rather as discrete fine crystals, spherules and nodules scattered in the host sediments. Nevertheless, Baker et al. (1996) found that early diagenetic siderite concretions (0.5-2 mm) form up to 30% of Triassic sandstones and mudstones from eastern Australia. Laterally continuous siderite-cemented offshore shelf sandstone sheets (15 cm thick) occur in Upper Cretaceous sequences from Canada (McKay et ai, 1995). 

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