Skip to main content

Currently Skimming:

2 Sources of Lead Contamination
Pages 12-24

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.


From page 12...
... This chapter the environment. describes the various sources that potentially contribute to lead contamination at or near a Superfund site (see Figure Lead-Bearing Mineral Deposits 2-1)
From page 13...
... These deposits include Metallic mineral deposits form when geologic pro- carbonate replacement, polymetallic veins, and seafloor cesses concentrate metals into small volumes of rock massive sulfides. They are the most common types of minfrom much larger, relatively dilute sources.
From page 14...
... , whereas acid-neutralizing capacity is highest in carbonate-hosted deposits, such as Natural Distribution of Lead those of the midcontinent and many igneous-related replacement deposits. Conversely, seafloor massive sulfide When lead deposits form from hydrothermal fluids, deposits and many vein deposits have relatively high sul- the lead concentration rarely terminates abruptly at the fide concentrations and host rocks that are poor acid neu- edge of an ore body but rather falls off gradually; this is tralizers, and these characteristics lead to the wide avail- primary dispersion.2 The original geologic dispersion reability of acid and dissolved metals in groundwater and flects the facts that ore-forming fluids typically invade a surface waters.
From page 15...
... saline fluids derived from adjacent sedimentary basins to the south. The largest lead deposits occur in the oldest sedimentary rocks, mainly the Bonneterre Dolomite and underlying Lamotte Sandstone near where they terminated against the older igneous rocks.
From page 16...
... . High-grade lead mineralization occurs principally in the Bonneterre Dolomite and underlying Lamotte Sandstone, but low-grade lead mineralization is widespread with barite in the residual ores of the overlying Potosi Dolomite and younger formations.
From page 17...
... ery efficiency. Given the relatively low solubility of lead in most surface Most mineral processing depends on the characterfluids, chemical weathering concentrates lead in residual istic properties of ore minerals that allow separation of materials in gossans (weathered ores)
From page 18...
... Lead minerals were recovered by hand, including primitive gravity separation techniques, and losses ranged from as little as 10% to greater than 50% of the total contained lead, which then ended up in mine waste and primitive tailings. Cerussite and galena were smelted locally with a series of open-air techniques that also failed to recover tens of percent of the lead contained in the ore mineral concentrates.
From page 19...
... Alkyl–lead additives are still used in aviation fuel, Furthermore, the 1926–1989 atmospheric lead input was specifically for small piston-engine aircraft. Although similar in magnitude to that of total lead released from soil emissions that result from the operation of those airplanes minerals by chemical weathering in the 12,000–14,000 was a tiny fraction of total atmospheric lead emissions in years since the last glacial retreat.
From page 20...
... higher in soils collected along drip lines of residential Construction debris is thus an important source of lead homes than in soils near streets or in parks (Mielke 1994; in many reclaimed urban sites. Superfund sites associated Mielke and Reagan 1998)
From page 21...
... . In the from countries where the use of lead paint is permitted Southeast Missouri Old Lead Belt, for example, chat left are particularly likely to have high lead concentrations.
From page 22...
... , which contain comprehensive lists ronmental Models of Mineral Deposits.
From page 23...
... U.S. Geological Survey Scientific Investigations Kendall, R.J., T.E.
From page 24...
... lead isotope characteristics of lead ore deposits of envi- usgs.gov/sir/2014/5086/pdf/sir2014-5086.pdf [accessed ronmental significance. Environ.


This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More information on Chapter Skim is available.