Footwall mineralization during Late Miocene extension along the West Cycladic Detachment System, Lavrion, Greece

Abstract

The West Cycladic Detachment System (WCDS) has been mapped from the western Cycladic islands to Lavrion (mainland Greece), where several top-to-SSW low-angle normal faults at different structural levels are observed. Near the detachment horizon, hydrothermal fluid flow originating from Miocene intrusions lead to high-temperature carbonate strata-bound Pb-Ag-Zn ore deposits. Zircon (U-Th)/He cooling ages from the mineralized footwall are 7.1 AE 0.6 to 7.9 AE 0.6 Ma. Carbon-and O-isotope analyses of the carbonate host indicate high water-to-rock ratios during brittle deformation-induced metasomatism, and that this interaction, unrelated to proximity of the intrusions, plays the dominant role in the mineralization. The Late Miocene geology of Lavrion is strikingly similar to Serifos island on the SE termination of the WCDS, both characterized by strong localization of detachment faulting and the interaction of brittle deformation with the injection of fluids related to granitoid intrusions.

Synkinematic skarns and fluid drainage along detachments: The West Cycladic Detachment System on Serifos Island (Cyclades, Greece) and its related mineralization

“…As in Elba, the Aegean skarns are famous for their rich and spectacular mineralogy. These are observed on the Greek mainland, at Lavrion (Skarpelis, 2007;Voudouris et al, 2008;Bonsall et al, 2011;Berger et al, 2013, Spry et al, 2014 and on the Cycladic islands of Santorini and Serifos (Skarpelis, 2002). Iron (and baryum) mineralization was mined at Serifos in the 19 th up to the beginning of the 20 th century.…”

“…The oldest ones were formed in the east in the Menderes Massif (Catlos et al, 2010) and the eastern Cyclades (Ikaria, Laurent et al, 2015;Beaudoin et al, 2015) and the youngest ones further west in Serifos and Lavrion (Liati et al, 2009;Berger et al 2013). This migration is likely due to the slab tear event that permitted the clockwise rotation of the Hellenides in the Middle Miocene .…”

The geological signature of a slab tear below the Aegean

“…(Altherr et al, 1982;Henjes-Kunst et al, 1988;Wijbrans and McDougall, 1988;Schliestedt et al, 1994;Keay et al, 2001;Hejl et al, 2002;Parra et al, 2002;Ring et al, 2003;Bröcker et al, 2004;Jolivet et al, 2004a;Kumerics et al, 2005;Brichau et al, 2006;Bröcker and Franz, 2006;Duchêne et al, 2006;Martin et al, 2006;Brichau et al, 2007;Skarpelis et al, 2008;Baltatzis et al, 2009;Iglseder et al, 2009;Liati et al, 2009;Seward et al, 2009;Bolhar et al, 2010;Brichau et al, 2010;Denèle et al, 2011;Ring et al, 2011;Schneider et al, 2011;Grasemann et al, 2012;Bargnesi et al, 2013;Berger et al, 2013;Bröcker et al, 2013;Soukis and Stockli, 2013;Beaudoin et al, 2014;Huet et al, 2014;Laurent et al, 2015) A C C E P T E D M A N U S C R I P T…”

Fossilized Bacteria in Fe-Mn-Mineralization: Evidence from the Legrena Valley, W. Lavrion Mine (Greece)

“…It represents a major Carbonate Replacement Deposit (CRD), associated with a granodiorite intrusion of Upper Miocene age [1]. The primary ore, composed of massive sulphides of sphalerite, pyrite and galena (B.P.G), has been studied by many authors [1][2][3][4][5][6][7]. Near a detachment horizon, hydrothermal fluids originating from Miocene intrusions led to high-temperature carbonate stratabound Pb-Ag-Zn ore deposits.…”

“…Although the Fe-Mn-mineralization is widespread along the detachment zones in the Attic-Cycladic belt (including Attica), it exhibits a complex mineralogical and chemical composition and more research is required for better understanding the genesis of that type of mineralization [1,5,7,[10][11][12].…”