Metalliferous deposits

Metall-. metallic, metal, -abfall, m. metal waste, waste metal, scrap metal, -ablagenmg, /. metalliferous deposit, -ader, /. metallic vein, metalliferous vein. 

Let us now consider the effects of Eh-pH conditions on the speciation state and solubility of manganese in aqueous solutions. Manganese complexes have been carefully studied in the last decade, owing to the discovery on ocean ffoors of economically important metalliferous deposits (nodules and crusts) in which Mn compounds are dominant. 

Os isotopes as tracers in seafloor hydrothermal systems a survey of metalliferous deposits from the TAG hydrothermal area, 26°N Mid-Atlantic Ridge. Earth Planet. Sci. Lett. 138, 105-119. 

The minerals produced in these metalliferous deposits reflect the mixing of the two end-member solutions (hydrothermal solution and seawater). The mixing process involves cooling of the hydrothermal fluids and heating of seawater, changes in pH and oxidation state, reaction with previously formed precipitates or sedimentary components, and nonequilibrium kinetic effects... 

Chemical Composition and Mineralogy of Marine Sediments Table 4 Minerals found in marine metalliferous deposits. 

International Journal of Surface Mining, Reclamation and Environment. A A Balkema (1389-5265) http //www.balkema.nl (accessed March TI, 2011) is incorporated as part of the larger Taylor Francis Group. The journal examines all aspects of surface mining technology and waste disposal systems relating to coals, oil sands, industrial minerals, and metalliferous deposits. Includes computer applications and automation processes. 

The ocean is host to a variety and quantity of inorganic raw materials equal to or surpassiag the resources of these materials available on land. Inorganic raw materials are defined here as any mineral deposit found ia the marine environment. The mineral resources are classified generally as iadustrial minerals, mineral sands, phosphorites, metalliferous oxides, metalliferous sulfides, and dissolved minerals and iaclude geothermal resources, precious corals, and some algae. The resources are mosdy unconsoHdated, consoHdated, or fluid materials which are chemically enriched ia certain elements and are found ia or upon the seabeds of the continental shelves and ocean basias. These may be classified according to the environment and form ia which they occur (Table 1) and with few exceptions are similar to traditional mineral deposits on land. 

Ocean Basins. Known consohdated mineral deposits in the deep ocean basins are limited to high cobalt metalliferous oxide cmsts precipitated from seawater and hydrothermal deposits of sulfide minerals which are being formed in the vicinity of ocean plate boundaries. Technology for drilling at depth in the seabeds is not advanced, and most deposits identified have been sampled only within a few centimeters of the surface. 

Fig. 2. Distribution of ( ) known and (o) suspected metalliferous sulfide deposits and active hydrothermal vents in the Pacific Ocean (42).

Deposits which are forming are frequentiy characterized by venting streams of hot (300°C) mineralized fluid known as smokers. These result in the local formation of metalliferous mud, rock chimneys, or mounds rich in sulfides. In the upper fractured zone or deep in the rock mass beneath the vents, vein or massive sulfide deposits may be formed by the ckculating fluids and preserved as the cmstal plates move across the oceans. These off-axis deposits are potentially the most significant resources of hydrothermal deposits, even though none has yet been located. 

Because little mass can precipitate from it, the brine, if related to deposition of the metalliferous muds, is likely to be a residuum of the original ore fluid. As it discharged into the deep, the ore fluid was richer in metals than in reduced sulfur. Mineral precipitation depleted the fluid of nearly all of its reduced sulfur without exhausting the metals, leaving the metal-rich brine observed in the deep. 

Metallic taste, 11 565 Metallic tungsten, 25 374 Metallic Type II superconductors, critical current density value in, 23 822 Metallic vanadates, 25 513 Metalliding, 15 251 Metalliferous oxides deposits of, 17 689-690 in ocean basins, 17 693 Metalliferous sulfide deposits, 17 690-691 Metalliferous sulfides, in ocean basins, 17 693-694... 

Two types of metal-rich hydrogenous deposits are formed on the seafloor iron-manganese oxides and polymetallic sulfides. The iron-manganese oxides have been deposited as nodules, sediments, and crusts. They are enriched in various trace elements, such as manganese, iron, copper, cobalt, nickel, and zinc, making them a significant repository for some of these metals. Most of the metals in the polymetallic sulfides are of hydrothermal origin. These sulfides have been deposited as metalliferous sediments aroimd hydrothermal systems and as rocks that infill cracks within former... 

CHAPTER 19 Metalliferous Sediments and Other Hydrothermal Deposits... 

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