Use of Primary Dispersion for Exploration of Mississippi Valley-Type Deposits

Barnes, H. L.; Lavery, Norman G.

doi:10.1016/b978-0-444-41653-7.50014-7

Cited by 2 publications

(3 citation statements)

References 3 publications

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“…The important influence of the non-carbonate phase on the distribution of the trace elements in carbonate rocks is a well-documented phenomena (Barber 1974;Pascal 1979;Dejonghe 1987;and others). As long as selective dissolution techniques are not more adequate, interference of these noncarbonate components will be present (Barber 1974 Kranz (1976) from the discordant Pb-Zn mineralizations from the eastern Alps (Wettersteinkalk) and by Lavery and Barnes (1971) from the Wisconsin Zn-Pb district (see also Barnes and Lavery 1977). The data reported by Ineson (1969Ineson ( , 1970 from the mineralized Dinantian limestones of the Pennine and Derbyshire ore fields are comparable.…”

Section: Dispersion Factors In Non-mineralized Carbonate Stratasupporting

confidence: 75%

Lithogeochemical patterns around Pb-Zn mineralizations in Dinantian carbonate rocks of (eastern) Belgium

Swennen

Viaene

1990

Mineral. Deposita

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Abstract. The lithogeochemical distribution patterns of Mg, Sr, Na, Zn, Pb, Fe, Mn, K, Corg (organic matter) and IR (insoluble residue) in the Dinantian limestones and dolomites from the eastern part of Belgium have been studied (Dinant and Verviers synclinorium). Comparison of geochemical data of non-mineralized strata revealed higher background values in the strata of the Verviers synclinorium where Pb-Zn mineralizations occur. In this area a relation may exist with the metallogenetic district (Herve-Vesdre-Theux district; proposed by Dejonghe 1985 b). However, the higher background values also could relate to the more restricted sedimentation conditions in the Verviers synclinorium as opposed to the more open marine conditions in the Dinant synclinorium. The influence of mineralization on the geochemistry of limestones is limited and unpredictable. In dolomites, however, the effect can be important. In these rocks, the lithogeochemical distribution of Zn, Pb and Mn can be subdivided into three populations, i.e. a regional background, a local high background and a halo population. The higher trace element concentrations in the halo population is caused by the existence of disseminated sulfide minerals (sphalerite, galena and pyrite) and Zn-bearing goethite (mainly pseudomorphs after pyrite) and Mn-oxides. The sulfides relate to the ore emplacement. In the local high background only the Zn-bearing oxides occur. Their presence and thus the development of the local high background relates to weathering processes.

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Section: Dispersion Factors In Non-mineralized Carbonate Stratasupporting

confidence: 75%

Lithogeochemical patterns around Pb-Zn mineralizations in Dinantian carbonate rocks of (eastern) Belgium

Swennen

Viaene

1990

Mineral. Deposita

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“…They found the extent of the dispersion directly correlates with the size of the vein and extends to a maximum distance of 53 m. Barnes and Lavery (1977) expanded on their original work and established aseries of zinc dispersion curves for the Upper Mississippi Valley district that allow for prediction of distance to, and size of, nearby ore zones (Fig. 3).…”

Section: Primary Dispersion Halos/rom Rock Geochemicalanalysismentioning

confidence: 96%

“…Background zinc concentration was found to be directly proportional to the clay content of the rock. Therefore, by Barnes and Lavery 1977) subtracting an amount of zinc proportional to the clay content in a mineralized sampie from the total zinc concentration, the amount of hydrothermally introduced zinc can be computed. If the distance between two sampies having 5 and 10 ppm, respectively, is 6.4 m, then the adjacent mineralization is about 3 m thiek and its contact is 7.2m from the lOppm sampie.…”

Section: Primary Dispersion Halos/rom Rock Geochemicalanalysismentioning

confidence: 99%

Lithogeochemical Investigations Applied to Exploration for Sediment-Hosted Lead-Zinc Deposits

Lavery¹,

Leach

Saunders

1994

Sediment-Hosted Zn-Pb Ores

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Sediment-hosted stratiform massive sulphide (Sedex) deposits and Mississippi Valley-type (MVT) deposits differ in morphology, but there is considerable overlap in their host rock lithology, regional setting, size, grade, metal ratios, age of host rocks, lead isotopes, sulphur isotopes, and genesis. Recent advances in the understanding of basin-derived formation fluids provide a framework for interpreting the lithogeochemical signatures of these deposits. The composition of the ore fluids for both types of deposits is controlled in part by fluid-rock reactions within sedimentary basins, but the nature of the sediments in the basins, the source of the fluids, the thermal gradient in the basin, the migratory history of the fluids, and the physical and chemical conditions in the deposition al environment cause variations in the lithogeochemical patterns present. Studies of modern sedimentary formation waters indicate that diagenetic fluid-rock reactions in basins can liberate and dissolve significant amounts of metals. The most metal-enriched formation waters are brines with more than 200000 ppm total dissolved solids. Some brines contain more than several hundred ppm combined Fe, Zn, Pb, and Ba, and minor amounts of Cu, Ag, Mn, Cd, As, Sb, Ni, Co, Mo, and Tl.Copper, Ag, As, Sb and Ba are reported in more than 60% of the Sedex deposits studied; Mn, Cd, Ni, Co, Au, Hg, Bi, B, Sn, Mo, F, Tl, Ge and Sr are reported in more than 20%; and V, Ga, In, Se, Cr and NH4 + are reported in more than 10% of the deposits. Geochemical variables which have received some exploration attention and which show promise as guides to Sedex deposits include: Tl, F, NH4 +, Hg, Pt, Pd, Zr, Cl-bearing minerals, rare earth elements, stable isotopes, and carbonaceous material.MVT districts were formed by ore-forming fluids which affected large volumes of the cmst. Widespread and isolated geochemical anomalies are, therefore, to be expected. Although there is a great diversity in deposit characteristics, it is possible to establish exploration criteria for additional deposits within a district or region. Geochemical analysis of insoluble residues has been used to define geochemical patterns that coincide with known ore trends and with ore-related geological features in the Southeast Missouri districts. Studies of rock alteration or identification of minerals precipitated from the brines can provide evidence of pathways used by the ore fluids. Hydrothermal dolomitization is the most important type of alteration; silicification is associated with ore in so me districts, and alteration of feldspars near ore has been identified in the Southeast Missouri lead district. Organic geochemistry and fluid inclusion studies are in progress and may yield practical exploration guides to MVT deposits.The presence of Cu, Mo, Pb, Zn, Ni, Co, Ag, Sb, As, Cd, and Ba in oil field brines/well scales, in MVT deposits, and in Sedex deposits lends credence to the use of these elements in lithogeochemical surveys. Many of the element associations described are bas...

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Use of Primary Dispersion for Exploration of Mississippi Valley-Type Deposits

Cited by 2 publications

References 3 publications

Lithogeochemical patterns around Pb-Zn mineralizations in Dinantian carbonate rocks of (eastern) Belgium

Lithogeochemical patterns around Pb-Zn mineralizations in Dinantian carbonate rocks of (eastern) Belgium

Lithogeochemical Investigations Applied to Exploration for Sediment-Hosted Lead-Zinc Deposits

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