Genetic Links between Irish-type Zn-Pb Deposits and Related Geochemical Halos

Yesares, L., Menuge, J. F., Drummond, D. A., Boyce, A. J. , Ashton, J. H. and Blakeman, R. J. (2019) Genetic Links between Irish-type Zn-Pb Deposits and Related Geochemical Halos. In: 15th SGA Biennial Meeting on Life with Ore Deposits on Earth, Glasgow, Scotland, 27-30 Aug 2019, pp. 463-466. ISBN 9780852619629

Full text not currently available from Enlighten.

Publisher's URL: https://www.sga2019glasgow.com/abstract

Abstract

A broad geochemical dispersion halo has been identified with a direct link to the underlying Tara Deep deposit at Navan, Ireland. In situ laser S isotope analyses have been performed on petrographically well characterized samples from the halo. Four mineral assemblages have been identified. 1) In black shales, laminated pyrite comprising thin layers of framboidal low-delta S-34 pyrite with minor interstitial sphalerite. 2) Pyritized calcarenites are widely distributed and occur chiefly as biodebris replaced by low-delta S-34 pyrite. 3) A replacive assemblage occurs as late remobilizations exhibiting both crosscutting and bedding-parallel styles, overprinting the early laminated pyrite. It comprises mostly marcasite, with minor pyrite, sphalerite, chalcopyrite, galena, stibnite, arsenopyrite and pentlandite, with high delta S-34 values. 4) Hydrothermal cherts comprise thick microcrystalline quartz bands rimmed by dolomite, associated with marcasite, pyrite, sphalerite, chalcopyrite, galena, Ni-sulfosalts and stibnite with high delta S-34 values. These results indicate overlapping diagenetic and multi-phase hydrothermal sulfide mineralization. First, laminated pyrite and pyritized calcarenites suggests a bacterial origin within sediments during early diagenesis. Later, hydrothermal chert and replacive sulfides suggest hydrothermal exhalation during early-mid diagenesis. Similarities in mineralogy and S isotope compositions suggest genetic links between the halo and the underlying Tara Deep deposit.

Item Type:Conference Proceedings
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Boyce, Professor Adrian and Drummond, Drew
Authors: Yesares, L., Menuge, J. F., Drummond, D. A., Boyce, A. J., Ashton, J. H., and Blakeman, R. J.
College/School:College of Science and Engineering > Scottish Universities Environmental Research Centre
ISBN:9780852619629

University Staff: Request a correction | Enlighten Editors: Update this record