Abstract
In SW Sardinia syngenetic to syndiagenetic Pb-Zn ores occur in Cambrian carbonates, along the unconformity between the Cambrian and Ordovician, in Permo-Triassic karsts and in vein-type deposits related to late Hercynian granites, which also contact-metamorphosed some Cambrian deposits. In all types of deposits the leadisotope ratios show similarly high μ (=238U/204Pb) and high W (=232Th/204Pb) values indicating a crustal origin for the lead. Most of the Cambrian ores contain isotopically similar or identical leads, whereas in the younger deposits the isotope ratios vary and suggest that especially the lead of Permo-Triassic ores may consist to a large extent of remobilized Cambrian, possibly also Ordovician, ore lead plus a Hercynian component.
The lead of three feldspar samples from Hercynian granites of the area also shows high μ and W values. Two of them are similar to the ore leads from a vein-type deposit and from contact-metamorphosed deposits. The third sample from the Capo Pecora granite contains a very unradiogenic lead that closely resembles many of the presumed Cambrian-Hercynian mixtures. Therefore, the possibility cannot be dismissed that at the time the Permo-Triassic ores were formed lead sources other than the already existing ores were present with the appropriate isotopic compositions.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Bechstaedt, Th., Boni, M., Selg, M.: From a clastic tidal shelf to an isolated carbonate platform: an effect of tensional tectonics in the lower Cambrian of SW Sardinia. Facies, 12:113–140 (1985)
Benz, J.P.: Le gisement plombo-zincifere d'Arenas (Sardaigne). Travaux du Laboratoire de Sciences de la Terre de l'Ecole des Mines, Nancy, (These): pp 126 (1964)
Boni, M.: Il Calcare Ceroide del Cambriano sardo: un deposito di laguna evaporitica? Rend. Soc. Geol. It., 83–85 (1964)
Boni, M.: The Permo-Triassic vein- and paleokarst-ores in southwest Sardinia: Contribution of fluid inclusion studies to their paleoenvironmental and genetic problems (in press)
Boni, M.: Mississippi valley type ore deposits in southwest Sardinia: a synthesis (in prep.)
Boni, M., Amstutz, G.C.: The Permo-Triassic paleokarst ores of SW Sardinia (Iglesiente-Sulcis): an attempt at a reconstruction of paleokarst conditions. In: Ore Genesis: The State of the Art. pp 73–82. Berlin Heidelberg: Springer 1982
Boni, M., Cocozza, T., Gandin, A., Perna, G.: Tettonica, sedimentazione e mineralizzazioni delle brecce al bordo sud-orientale della piattaforma carbonatica cambrica (Sulcis, Sardegna). Mem. Soc. Geol. It. 23:111–122 (1981)
Boni, M., Malafronte, A.: Structural setting and genesis of ore-bodies in carbonate rocks in the Mte. Atzei — Mte. Ega mining area (Sulcis, SW Sardinia). Min. Dep. 18:57–69 (1983)
Brevart, O., Dupre, B., Allegre, C.J.: Metallogenic provinces and the remobilization process studied by lead isotopes: Lead-zinc ore deposits from the Massif Central, France. Econ. Geol. 77:564–575 (1982)
Brusca, C., Dessau, G.: I giacimenti piombo-zinciferi di S. Giovanni (Iglesias) nel quadro della geologia del Cambrico Sardo. Ind. Min. 19 (9), (10), (11):470–494 (1968)
Carannante, G., Cocozza, T., D'Argenio, B.: Late Precambrian-Cambrian geodynamic setting and tectono-sedimentary evolution of Sardinia (Italy). Boll. Soc. Geol. It. 103 (1):121–128 (1984)
Carmignani, L., Cocozza, T., Ghezzo, C., Pertusati, P.C., Ricci, C.A.: Lineamenti del basamento sardo. Soc. Geol. It., Guide Geologiche Regionali: Guida alla geologia del Paleozoico Sardo, 11–23 (1982)
Civita, M., Cocozza, T., Forti, P., Perna, G., Turi, B.: Idrogeologia del bacino minerario dell'Iglesiente (Sardegna Sud Occidentale). Mem. Ist. It. Speleol. 2, ser. 11:pp 137 (1983)
Cocozza, T., Conti, L., Cozzupoli, D., Lombardi, G., Scharbert, S., Traversa, G.: Rb/Sr age and geo-petrologic evolution of crystalline rocks in southern Sulcis (Sardinia). N. Jb. fuer Geol. and Paleont. Mh., 95–102 (1977)
Cocozza, T.: The Cambrian of Sardinia. Mem. Soc. Geol. It. 20:163–187 (1979)
Cocozza, T., Jacobacci, A., Nardi, R., Salvadori, I.: Schema stratigrafico-strutturale del massiccio sardo-corso e minerogenesi della Sardegna. Mem. Soc. Geol. It. 13:85–186 (1974)
Cumming, G.L., Richards, J.R.: Ore lead isotope ratios in a continuously changing earth. Earth and Planet. Sc. Let. 28:155–171 (1975)
Del Moro, A., Di Simplicio, P., Ghezzo, C., Guasparri, G., Rita, F., Sabatini, G.: Radiometric data and intrusive sequence in the Sardinian batholith. N. Jb. fuer Mineralogie, Abh., 126:28–4 (1975)
Di Simplicio, P., Ferrara, G., Ghezzo, C., Guasparri, G., Pellizzer, R., Ricci, C.A., Rita, F., Sabatini, G.: Il metamorfismo e il magmatismo paleozoico nella Sardegna. Rend. Soc. It. Petr. 30:979–1068 (1975)
Doe, B.R., Zartman, R.E.: Plumbotectonics, the Phanerozoic. In: Geochemistry of Hydrothermal Ore Deposits, ed. H.L. Barnes, pp 22–70. New York: J. Wiley & Sons 1979
Gandin, A., Padalino, G., Violo, M.: Correlation between sedimentation environment and ore prospecting. Sedimentological and ore genesis studies of Cambrian “arenarie” and “dolomie rigate” formations (Sardinia, Italy): deposition and concentration of barite in an evaporitic environment. Rend. Soc. It. Min. e Petr. 30:251–303 (1974)
Ghezzo, C., Orsini, J.B.: Lineamenti strutturali e composizionali del batolite ercinico sardo-corso in Sardegna. Soc. Geol. It., Guide Geologiche Regionali: Guida alla Geologia del Paleozoico Sardo: 165–181 (1982)
Koeppel, V.: Summary of lead isotope data from ore deposits of the Eastern and Southern Alps: some metallogenetic and geotectonic implications. In: H.J. Schneider (ed) Mineral Deposits of the Alps and of the Alpine Epoch, pp 162–168. Berlin Heidelberg: Springer 1983
Koeppel, V., Schroll, E.: Lead isotopes of palaeozoic strata-bound to stratiform galena-bearing sulfide deposits of the Eastern Alps (Austria); implications for their geotectonic setting. Schweiz. Min. Petr. Mitt. 63:347–360 (1983)
Minzoni, N.: Precambriano nel Sulcis meridionale (Sardegna). Miner. Petr. Acta, 24:51–56 (1980)
Moore, J.McM.: Influence of structure on the metal deposits of southwest Sardinia, Italy. Trans. Inst. Min. Met. Sect. B 78:135–147 (1969)
Moore, J.McM.: Supergene mineral deposits and physiographic development in southwest Sardinia, Italy. Trans. Inst. Min. Met. Sect. B 81:59–66 (1972)
Poll, J.J.K.: The geology of the Rosas — Terreseo area, Suicis, South Sardinia. Leidse Geol. Med. 35:117–208 (1966)
Salvadori, I., Zuffardi, P.: Guida per l'escursione a Montevecchio e all'Arcuentu. Itiner. Geol. Min. Giac. in Sardegna, Ente minerario Sardo 1:29–44 (1973)
Stacey, J.S., Kramers, J.D.: Approximation of terrestrial lead isotope evolution by a two-stage model. Earth and Planet Sc. Lett 26:207–221 (1975)
Stille, H.: Bemerkungen betreffend die „Sardische“ Faltung und den Ausdruck „ophiolitisch“. Zs. Deutsch. Geol. Ges. 91:771–773 (1939)
Swainbank, I.G., Shepherd, T.J., Caboi, R., Massoli-Novelli, R.: Lead isotopic composition of some galena ores from Sardinia. Periodico di Mineralogia — Roma 51:275–286 (1982)
Wilke, A., Ehrendreich, H., Münch, W., Siebdraht, H.: Montangeologische Untersuchungen in italienischen Blei-Zink-Erz-Bergwerken; a) im Gebiet von Iglesias, Sardinien; b) in den Bergamasker Alpen. Resumé. Erzmetall. 13:459 (1960)
Zuffardi, P., Salvadori, I.: Supergene sulfides and sulfates in the supergene zones of sulfide ore deposits. G.C. Amstutz (ed.): Sedimentology and ore genesis, Developments in sedimentology, v. 2, pp 91–99, Elsevier (1964)
Zuffardi, P.: Sulla composizione isotopica del piombo di alcune galene sarde e sul suo significato geo-giacimentologico. Symp. sui problemi minerari della Sardegna, Cagliari-Iglesias, Atti pp 33–40 (1965)
Zuffard, P.: Remobilization in Sardinian lead-zinc deposits. In: Remobilization of Ores and Minerals. Ente minerario Sardo, Cagliari, 283–292 (1969)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Boni, M., Koeppel, V. Ore-lead isotope pattern from the Iglesiente-Sulcis Area (SW Sardinia) and the problem of remobilization of metals. Mineral. Deposita 20, 185–193 (1985). https://doi.org/10.1007/BF00204563
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00204563