Lead isotope results of acid leaching experiments on acid volcanics and black shales in an ore environment.

Gulson, Brian L.

doi:10.2343/geochemj.11.239

Cited by 6 publications

(2 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Common lead of magmatic rocks can be obtained from K-feldspars, time-integrated correction for U (and Th) decay of raw isotopic ratios and, to some extent, from analyses of residual rock fractions . In contrast, separate leachate and residue analyses may give more information than single whole-rock analyses about the lead contributed by basement lithologies to ore fluids (e.g., Gulson 1977;Curti 1987;Chiaradia and Fontboté 2003).…”

Section: Metallogenic Evolution Of the Tien Shan And Altaymentioning

confidence: 99%

Lead isotope variations across terrane boundaries of the Tien Shan and Chinese Altay

et al. 2006

View full text Add to dashboard Cite

The Altaid orogen was formed by aggregation of Paleozoic subduction-accretion complexes and Precambrian basement blocks between the Late Proterozoic and the Early Mesozoic. Because the Altaids are the site of abundant granitic plutonism and host some of the largest gold deposits in the world, understanding their formation has important implications on the comprehension of Phanerozoic crustal growth and metallogeny. In this study, we present the first extensive lead isotope data on magmatic and metasedimentary rocks as well as ore deposits of the southern part of the Altaids, including the Tien Shan (Tianshan) and southern Altay (Altai) orogenic belts. Our results show that each terrane investigated within the Tien Shan and southern Altay is characterized by a distinct Pb isotope signature and that there is a SW-NE Pb isotope gradient suggesting a progressive transition from a continental crust environment in the West (the Kyzylkum and Kokshaal segments of the Southern Tien Shan) to an almost 100% juvenile (MORB-type mantle-derived) crust environment in the East (Altay). The Pb isotope signatures of the studied ore deposits follow closely those of magmatic and metasedimentary rocks of the host terranes, thus supporting the validity of lead isotopes to discriminate terranes. Whereas this apparently suggests that no unique reservoir has been responsible for the huge gold concentration in this region, masking of a preferential Pb-poor Aubearing reservoir by mixing with Pb-rich crustal reservoirs during the mineralizing events cannot be excluded.

show abstract

Section: Metallogenic Evolution Of the Tien Shan And Altaymentioning

confidence: 99%

Lead isotope variations across terrane boundaries of the Tien Shan and Chinese Altay

et al. 2006

View full text Add to dashboard Cite

show abstract

“…An alternative approach is the analysis of rock leachates, as already carried out in metallogenic studies by, among others, Gulson (1977), Curti (1987), and MacFarlane and Petersen (1990). The present study is a systematic application of lead isotope analyses of separate leachate and residue fractions to a broad spectrum of commonly investigated magmatic and metamorphic rocks.…”

Section: Introductionmentioning

confidence: 99%

Separate lead isotope analyses of leachate and residue rock fractions: implications for metal source tracing in ore deposit studies

Chiaradia

Fontboté

2003

Miner Deposita

View full text Add to dashboard Cite

ARTICLEMassimo Chiaradia AE Lluı´s FontboteŚ eparate lead isotope analyses of leachate and residue rock fractions: implications for metal source tracing in ore deposit studies Abstract Separate lead isotope analyses of leachate and residue fractions are applied to a broad spectrum of rocks commonly investigated in metallogenic studies. Resulting data highlight a systematic behavior of leachate and residue fractions with respect to lead isotope compositions, which essentially depends on the mineralogical composition of the rock. Granitoid and high-grade metamorphic rocks have residue compositions virtually identical to common lead. In contrast, low-grade metasedimentary rocks may have residue compositions swamped by radiogenic lead of leach-resistant zircons. Mafic magmatic rocks have residues that are often more radiogenic than leachates, depending on the ratio of leach-refractory zircons to common lead in the residual fraction of these rocks. Separate leachate and residue analyses of source rocks provide two lead isotope end members whose mixture may represent lead with the appropriate ore fluid composition. Our leaching experiments indicate that hot acid solutions (and by inference hydrothermal fluids) preferentially leach radiogenic lead from medium-to high-grade metamorphic and granitoid rocks, whereas they preferentially leach common lead from low-grade metasedimentary and mafic magmatic rocks. The method presented in this study provides a reliable alternative to other methods (i.e., age-correction of bulk-rock compositions) for the determination of the common lead signature of felsic to intermediate magmatic rocks. This may be preferable to age-corrected bulk-rock analyses, where ages to apply for corrections of bulk-rock data are not known or where moderately to highly altered rocks must be used. Case studies of orogenic gold and MVT districts of Peru (Pataz and San Vicente, respectively) show that separate leachate and residue lead isotope analyses carried out systematically on whole rocks allow a more thorough evaluation of metal source reservoirs than does the standard method of age-corrected or uncorrected bulk-rock analyses.

show abstract

Isotopic and geochemical studies on crustal effects in the genesis of the woodlawn Pb-Zn-Cu deposit

Gulson

1977

Contr. Mineral. and Petrol.

View full text Add to dashboard Cite

Lead isotope results of acid leaching experiments on acid volcanics and black shales in an ore environment.

Cited by 6 publications

References 12 publications

Lead isotope variations across terrane boundaries of the Tien Shan and Chinese Altay

Lead isotope variations across terrane boundaries of the Tien Shan and Chinese Altay

Separate lead isotope analyses of leachate and residue rock fractions: implications for metal source tracing in ore deposit studies

Isotopic and geochemical studies on crustal effects in the genesis of the woodlawn Pb-Zn-Cu deposit

Contact Info

Product

Resources

About