| More

MINERALOGY AND GEOCHEMISTRY OF THE TRIADESGALANA PB-ZN-AG-AU INTERMEDIATE-HIGH SULFIDATION EPITHERMAL MINERALIZATION, MILOS ISLAND, GREECE

Views: 624 Downloads: 245
K. Papavasiliou, P. Voudouris, C. Kanellopoulos, D. Alfieris, S. Xydous
K. Papavasiliou, P. Voudouris, C. Kanellopoulos, D. Alfieris, S. Xydous

Abstract


The Triades-Galana Pb-Zn-Ag-Au mineralization is a shallow-submarine epithermal mineralization located along NE-trending faults, NW Milos Island, Greece. It is hosted in 2.5–1.4 Ma pyroclastic rocks and is genetically related to andesitic/dacitic lava domes. Mineralization occurs as breccias, quartz-barite galena veins and stockworks within sericite-adularia or kaolinitic altered rocks. The mineralization is enriched in Mo, W and base- and precious metals (e.g. Pb, Zn, Ag) similarly to the neighbouring mineralization at Kondaros-Katsimouti and Vani, indicating common source of metals from a deep buried granitoid feeding western Milos with metals and volatiles. Paragenetic relations suggest early deposition of pyrite, followed by famatinite, polybasite and Ag-rich tetrahedrite, and then by enargite, suggesting fluctuating sulfidation states during ore formation. The evolution from Sb- towards As-rich enrichment indicate a renewed magmatic pulse (probably in the form of magmatic gases) in the hydrothermal system. Silver is present in the structure of sulfosalts (up to 66.2 wt.% in polybasite-pearceite, 15.1 wt.% in tetrahedrite and 60 wt. % in pyrargyrite). Boiling processes (as evidenced by the presence of adularia accompanying intermediate-sulfidation ore) and mixing with seawater (presence of hypogene lead chlorides) and contemporaneous uplift, contributed to ore formation.

Keywords


Silver mineralogy; epithermal; Triades-Galana; Milos Island

Full Text:

PDF

References


Alfieris, D., 2006. Geological, geochemical and mineralogical studies of shallow submarine

epithermal mineralization in an emergent volcanic edifice, at western Milos island, Greece,

PhD thesis, University of Hamburg, Germany, 211 pp.

Alfieris, D. and Voudouris, P., 2005. Ore mineralogy of transitional submarine to subaerial

magmatic-hydrothermal deposits in W. Milos, Greece, In: Cook, N.G. and Bonev, I., eds.,

Au-Ag-Te-Se deposits, Geochemistry, Mineralogy and Petrology, 43, Sofia, 1-6.

Alfieris, D., Voudouris, P. and Spry, P.G., 2013. Shallow submarine epithermal Pb-Zn-Cu-Au-Ag-

Te mineralization on western Milos Island, Aegean Volcanic Arc, Greece: Mineralogical,

Geological and Geochemical constraints, Ore Geology Reviews, 53, 159-180.

Altherr, R. and Siebel, W., 2002. I-type plutonism in a continental back-arc setting:Miocene granitoids

and monzonites from the central Aegean Sea, Greece, Contrib.Mineral.Petrol., 143, 397-415.

de Ronde, C.E., Massoth, G.J., Butterfield, D.A., Christenson, B.W., Ishibashi, J., Ditchburn, R.G.,

Hannington, M.D., Brathwaite, R.L., Lupton, J.E., Kamenetsky, V.S. and Graham, I.J., 2011.

Submarine hydrothermal activity and gold-rich mineralization at Brothers Volcano,

Kermadec Arc, New Zealand, Mineralium Deposita, 46(5-6), 541-584.

Einaudi, M.T., Hedenquist, J.W. and Inan, E.E., 2003. Sulfidation state of fluids in active and extinct

hydrothermal systems: Transitions from porphyry to epithermal environments. In: Simmons,

S.F. and Graham, I., eds., Volcanic, Geothermal, and oreforming fluids: Rulers and witnesses

of processes within the Earth, Soc. Econ. Geol., Special Publication, 10, 285-313.

Fytikas, M., Innocenti, F., Kolios, N., Manneti, P., Mazzuoli, R., Poli, G., Rita, F. and Villari, L.,

Volcanology and petrology of volcanic products from the island of Milos and

neighbouring islets, J. Volcanol. Geotherm. Res., 28, 297-317.

Glasby, G.P., Papavassiliou, C.T., Mitsis, J., Valsami-Jones, E., Liakopoulos, A. and Renner, R.M.,

The Vani manganese deposit, Milos island, Greece: a fossil stratabound Mn-Ba-Pb-

Zn-As-Sb-W-rich hydrothermal deposit. In: Fytikas, M. and Vougioukalakis, G.E., eds., The

South Aegean Active Volcanic Arc: Present Knowledge and Future Perspectives,

Developments in Volcanology, 7, Elsevier, 255-291.

Hauck, M., 1988. Kuroko-type ore deposits on the Aegean Islands, Greece. In: Friedrich, G.M. and

Herzig, P.M., eds., Base metal sulfide deposits, Springer Verlag, Berlin, 216-228.

Jolivet, L., and Brun, J.P., 2010. Cenozoic geodynamic evolution of the Aegean region, Int. J. Earth

Sci., 99, 109-138.

Kati, M., Voudouris, P., Valsami-Jones, E., Magganas, A., Baltatzis, E., Kanellopoulos, C. and

Mavrogonatos, C., 2015, April. Cinnabar, arsenian pyrite and thallium-enrichment in active

shallow submarine hydrothermal vents at Paleochori Bay, Milos Island, Greece, EGU

General Assembly Conference Abstracts, 17, 13046 pp.

Katsouri, S., Scott, S.D., Gorton, M.P., Magganas, A., Valsami-Jones, E., Baltatzis, E. and Kati, M.,

Formation of hydrothermal sulphides in active shallow water systems: the role of

freshwater vs seawater, SEG Eugen Stumpfl Memorial Symposium, Predictive Mineral

Discovery Under Cover. Seccion, 1, 220-223.

Kilias, S.P., Naden, J., Cheliotis, I., Shepherd, T.J., Constandinidou, H., Crossing, J. and Simos, I.,

Epithermal gold mineralisation in the active Aegean volcanic arc: the ProfitisIlias

deposit, Milos Island, Greece, Miner. Deposita, 36, 32-44.

Kilias, S.P., Nomikou, P., Papanikolaou, D., Polymenakou, P.N., Godelitsas, A., Argyraki, A.,

Carey, S., Gamaletsos, P., Mertzimekis, T.J., Stathopoulou, E. and Goettlicher, J., 2013. New

insights into hydrothermal vent processes in the unique shallow-submarine arc-volcano,

Kolumbo (Santorini), Greece, Scientific Reports, 3, 2421, 1-13.

Liakopoulos, A., Glasby, G.P., Papavassiliou, C.T. and Boulegue, J., 2001. Nature and origin of the

Vani manganese deposit, Milos, Greece: an overview, Ore Geol Rev, 18, 181-209.

Marschik, R., Bauer, T., Hensler, A.S., Skarpelis, N. and Holzl, S., 2010. Isotope Geochemistry of

the Pb-Zn-Ba(-Ag-Au) Mineralization at Triades-Galana, Milos Island, Greece, Res.

Geology, 60, 335-347.

Naden, J., Kilias, S.P. and Darbyshire, D.B.F., 2005. Active geothermal systems with entrained

seawater as analogues for transitional continental magmato-hydrothermal and volcanichosted

massive sulfide mineralization-the example of Milos Island, Greece, Geology, 33,

-544.

Plimer, I., 2000. Milos Geologic History. KOAN Publishing House, Athens, 262 pp.

Scotney, P.M., Roberts, S., Herrngton, R.J., Boyce, A.J. and Burgess, R., 2005. The development of

volcanic hosted massive aulfide and barite gold orebodies on Wetar Island, Idonesia,

Mineralium Deposita, 40, 76-99.

Shimizu, M., Kato, A., Matsubara, S., Criddle, A.J. and Stanley, C.J., 1993. Watanabeite,

Cu4(As,Sb)2S5, a new mineral from the Teine mine, Sapporo, Hokkaido, Japan, Mineral.

Mag., 57, 643-649.

Sillitoe, R.H., Hannington, M.D. and Thompson, J.F.H., 1996. High-sulfidation deposits in the

volcanogenic massive sulfide environment, Econ. Geol., 91, 204-212.

Stewart, A.L. and McPhie, J., 2003. Setting of epithermal Au deposits in a modern volcanic island

arc setting, Milos, Greece: Implications for mineral exploration, Mineral Exploration and

Sustainable Development. Millpress, Rotterdam, 533-536.

Stewart, A.L. and McPhie, J., 2006. Facies architecture and Late Pliocene-Pleistocene evolution of

a felsic volcanic island, Milos, Greece, Bull. Volcanol., 68, 703-726.

Vavelidis, M. and Melfos, V., 1997. Two plumbian tetrahedrite-tennantite occurrences from

Maronia area (Thrace) and Milos island (Aegean Sea, Greece), Eur. J. Mineral., 9, 653-657.

Vavelidis, M. and Melfos, V., 1998. Fluid inclusion evidence for the origin of the barite silver-goldbearing

Pb-Zn mineralization of the Triades area, Milos Island, Greece, Bull. Geol. Soc.

Greece, 32, 137-144.


Refbacks

  • There are currently no refbacks.


Copyright (c) 2017 K. Papavasiliou, P. Voudouris, C. Kanellopoulos, D. Alfieris, S. Xydous

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.