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Geology topics

Z. S. Altschuler

Publications and source records attributed to Z. S. Altschuler.

8 recordsLinked to original sources
USGS1983

Sulfur diagenesis in Everglades peat and origin of pyrite in coal

The pattern of sulfur transformation in peat across the Everglades basin indicates that pyrite formation in organic-rich swamps depends on the use of organic oxysulfur compounds in dissimilatory respiration by sulfur-reducing bacteria. This paragenesis explains the primary distribution of sulfur compounds in low-sulfur coals and possibly in most coals and many organic-rich soils and sediments. It also accounts for the occurrence of framboidal pyrite bound in fossil tissue in coal and sediments.

Florida↗
USGS1969

The relationship of the rare-earth composition of minerals to geological environment

It has been known for a long time that the composition of the lanthanides in minerals is controlled to a large degree by crystallo-chemical factors, but is also greatly influenced by changes in geological environment. In general, igneous rocks rich in silica are favourable for the concentration of the heavy lanthanides and yttrium; those low in silica and high in carbonate are favourable for the concentration of the light lanthanides. These generalizations are illustrated by summaries of the available data on monazite, sphene, and apatite from different geological environments. Apatite of marine sedimentary origin (a large potential source of rare earths) shows marked depletion of cerium, as has been noted previously for sea water.

Geochimica et Cosmochimica Acta↗
USGS1966

Rare earths in phosphorites: Geochemistry and potential recovery

Rare earths are but trace constituents of marine apatite. However, as millions of tones of such apatite are dissolved annually to make phosphoric acid, an opportunity exists for greatly increasing RE output as by-product of fertilizer production. New, complete, quantitative analysis of RE in representative apatite concentrates reveal that the potential for by-product RE equals current production. The RE assemblage in marine apatite is unusual, showing depletion in cerium and relative enrichment in the heavier lanthonons, a favorable distribution for RE technology and utilization.

Open-File Report↗
USGS1963

Transformation of montmorillonite to kaolinite during weathering

Extensive deposits of kaolinite in Florida are formed by transformation of montmorillonite during low-temperature supergene weathering. The transformation occurs by intracrystalline leaching of interlayer cations and tetrahedral silica layers. Interposition of stripped layers within montmorillonite creates a regular 1:1 mixed-layered montmorillonite-kaolinite, a new clay structure. Kaolin-like layers are nourished by lateral epitaxy, as the iron-rich montmorillonite decomposes. Hexagonal outgrowths of new kaolinite develop at the edges of montmorillonite flakes and nucleate new vertical growth. Kaolinitic sands impregnated with goethite are ultimately formed, and the released silica enriches groundwater and forms secondary chert.

Florida↗
USGS1958

Determination of the oxidation state of uranium in apatite and phosphorite deposits

Geological and mineralogical evidence indicate that the uranium present in apatite may proxy for calcium in the mineral structure as U(IV). An experimental investigation was conducted and chemical evidence was obtained that establishes the presence of U(IV) in apatite. The following analytical procedure was developed for the determination of U(IV). Carbonatefluorapatite is dissolved in 1.5 M orthophosphoric acid at a temperature of 5°C or slightly below and fluorapatite is dissolved in cold 1.2 M hydrochloric acid (approximately 5°C) containing 1.5 g of hydroxylamine hydrochloride per 100 ml. Uranium(IV) is precipitated by cupferron using titanium as a carrier. The uranium in the precipitate is separated by use of the ethyl acetate extraction procedure and determined fluorimetrically. The validity and the limitations of the method have been established by spike experiments.

Geochimica et Cosmochimica Acta↗