Lead, Mexico deposits

Rye RO (1966) The C, H, and O isotopic composition of the hydrothermal fluids responsible for the lead-zinc deposits at Providencia, Zacatecas, Mexico. Econ Geol 61 1399-1427... 

Plattnerite is a lead(lV) oxide mineral with composition Pb02, named after the German metallurgist K.F. Plattner (1800-58). It occurs as black sub-metallic botryoidal masses, nodules and crusts or as prismatic crystals and forms by the oxidation of lead ore deposits in areas such as Leadhills (Scotland), Laurion (Attiki, Greece), Durango (Mexico), Tsumeb (Namibia) and Bisbee (Arizona, USA), Rutley (1988). 

Lead is the 35th most abundant element on Earth. Although it has been found in its free elemental metal state, it is usually obtained from a combination of the following ores galena (PbS), anglesite (PbSO ), cerussite (PbCOj), and minum (Pb O ). Lead ores are located in Europe (Germany, Rumania, and France), Africa, Australia, Mexico, Peru, Bolivia, and Canada. The largest deposits of lead in the United States are in the states of Missouri, Kansas, Oklahoma, Colorado, and Montana. 

The natural ore is quarried or mined in many areas of North America and Europe. Leading North American regions include Canada, Mexico, and in the United States, California, Texas, Nevada, Iowa, Kansas, Ohio, Indiana, and Michigan. In Europe, France, Spain, Italy, the United Kingdom, and Russia have significant deposits of natural gypsum, as does Germany. 

Occurs in low-temperature silver deposits commonly associated with silver and lead minerals. Found in various Western States in the United Stales, and as superb crystals at Arizpe and Las Chiapas. Mexico ill Chile, Peru, Sardinia. Germany, and Australia. 

VANADINITE. The mineral vanadimte corresponds to the formula Pb VO Cl, being composed of lead chloride and lead vanadate in the proportion of 90.2% of the former and 9.8% of the latter. It crystallizes in the hexagonal system, is usually prismatic, but the ciystals are often skeletal or cavernous it may be found in crusts. Its fracture is uneven brittle hardness. 2.75-3 specific gravity. 6.86 fresh fractures show a resinous luster color, yellow, yellowish-brown, reddish-brown, and red streak, white to yellowish translucent to opaque. Vanadinite, not a common mineral, occurs as an alteration product in lead deposits. It is found in the Ural Mountains, Austria, Spain, Scotland, Morocco, the Transvaal, Argentina, and Mexico, In the United States it occurs in Arizona, New Mexico, and South Dakota, It is used as an ore of vanadium and to some extent of lead as well. It is interesting to note that this mineral was first described as a chromate upon its discovery in Mexico in 1801, It was not until the discovery of the element vanadium in 1830 that the true nature of this compound was known. 

A major zinc ore is ZnS (sphalerite) which frequently occurs with the major lead ore PbS (galena). The lead-zinc ores usually contain recoverable quantities of copper, silver, antimony, and bismnth as well, Major deposits of Ihis type are worked in Australia, the United States, Canada, Mexico, Peru, the former Yugoslav Republics, and the former Soviet Union. Two other important zinc ores are ZnCC>3 (smithsonite) and iron-zinc-manganese oxide (franklinite). Several of these minerals are described under separate alphabetical entries. 

The Metallurgy of Lead. The principal ore of lead is galena, PbS, which occurs, often in beautiful cubic crystals, in large deposits in the United States, Spain, and Mexico. The ore is first roasted until part of it has been converted into lead oxide, PbO, and lead sulfate, PbS04. The supply of air to the furnace is then cut off, and the temperature is raised. Metallic lead is then produced by the reactions... 

Currently in the United States, most of the lead produced comes from mines in Missouri, Alaska, Idaho, and Montana, primarily from lead-zinc and lead ores (361, 362). Worldwide, major lead deposits exist in association with zinc, silver, and/or copper (362). There are five major geological types of lead deposits volcanic-hosted massive sulfide deposits [Canada, Cyprus, Japan, Australia (Tasmania), Turkey] sediment-hosted deposits of sulfides interbedded with shales, and so on, formed in an anaerobic marine environment [Australia, Canada, Germany, United States (Alaska)] strata-bound carbonate deposits containing sulfide minerals [United States (Mississippi Valley), southern European Alps, Canada, Poland] sandstone-hosted deposits of finely crystalhne sulfides (Canada, France, Morocco, Sweden) and vein deposits of coarsely crystalline sulfide aggregates (western United States, Germany, Japan, Mexico, Peru) (364). The wide variety of compositions seen for lead minerals is illustrated by the representative lead minerals listed in Table XV (3,47). Below, we discuss the lead minerals that are most prevalent in nature in more detail. 

In addition to the U.S., the use of lead shot is now banned - sometimes voluntarily, sometimes by legislation - locally or nationally in hunting waterfowl in Australia, Canada, Italy, Mexico, Denmark, Finland, the Netherlands, Norway, Sweden, Switzerland, Germany, Japan, and the United Kingdom. In 1995, the British Department of the Environment recommended that lead-free shot be used when shooting over or within 300 m of a wetland if there is a possibility that the shot would be deposited in it. Beginning in 1997,... 

Silver mines have been known from time immemorial. The largest deposits of silver were in Greece, Spain, and Germany. After the discovery of America silver deposits were also found in Peru and Mexico. Lead minerals are often observed... 

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