2014 GSA Annual Meeting in Vancouver, British Columbia (19–22 October 2014)

Paper No. 186-11
Presentation Time: 11:10 AM

STRUCTURAL FRAMEWORK OF THE STRATONI FAULT CORRIDOR, KASSANDRA MINING DISTRICT, NORTHERN GREECE


SIRON, Chris R.1, THOMPSON, John F.H.1, RHYS, David2, BAKER, Tim3, RUSSELL, Sally4, TSITSANIS, Pavlos4 and RANDALL, Scott4, (1)Department of Earth and Atmospheric Sciences, Cornell University, Snee Hall, Ithaca, NY 14853, (2)Panterra Geoservices Inc, 14180 Greencrest Drive, Surrey, BC V4P1L9, Canada, (3)Eldorado Gold Corporation, 1188 Bentall 5 - 550 Burrard Street, Vancouver, BC V6C 2B5, Canada, (4)Hellas Gold SA, Vassilissis Sofias 23A Ave, Athens, 10674, Greece

The Kassandra Mining District encompasses 12 Moz of gold contained in porphyry and intrusion-related carbonate-hosted replacement-style orebodies. The Stratoni fault corridor is host to economically significant Au- and Ag-rich base metal massive sulfides at Madem Lakkos (>10MT historic production), Mavres Petres (1.14Mt at 181g/t Ag, 6.8% Pb and 11.3% Zn) and the Mn-rich Au deposit at Piavitsa.

The Stratoni fault broadly defines the transition between the hanging wall Vertiskos and the footwall Kerdyllia assemblages of the Serbo-Macedonian Massif. Outcrop and drill core observations suggests a gradational contact between carbonaceous biotite gneiss and amphibolite hanging wall rocks with quartzo-feldspathic biotite gneiss, granite gneiss and marble in the footwall. These rocks underwent ductile deformation with a later brittle tectonic overprint.

Consistent deformation patterns in each assemblage suggest that both witnessed the same tectonic deformation events. These include (i) penetrative shallow SW-dipping (S1) foliation defined by alignment of peak metamorphic minerals; (ii) inclined, tight to isoclinal (F2) folds and associated south-dipping axial planar (S2) cleavage with F2 axial planes favoring top-to-the north transport; (iii) subsequent low-strain, spaced and steeply dipping (S3) foliation which warps the previously developed fabrics and is likely associated with a second generation of km-scale, upright, open to closed (F3) folds.

The strongly mineralized WNW-trending Stratoni fault has an approximate strike-length of 12 km. The fault consists of a complex semi-brittle shear zone displaying cataclastic textures with development of an internal foliation and pressure solution fabrics which localized slip, often associated with younger phases of banded fault gouge, matrix-supported breccia. Textures along with kinematic indicators suggest deformation under post-ductile semi-brittle conditions that define top-to-the SSW normal relative movement, demonstrating NNE-SSW extension that postdates regional ductile deformation. Extension along the Stratoni fault controlled Au-rich massive sulfide replacement of marble within and adjacent to the fault and may have influenced the emplacement of porphyritic intrusions.