Northeastern Section - 49th Annual Meeting (23–25 March)

Paper No. 4
Presentation Time: 5:10 PM

COMPILING OF LITHOLOGOSTRATIGRAPHIC-TECTONIC SECTIONS, INCREASE SUBSTANTIALLY RESOURCES OF CU-FE, CU-FE, ZN, AU, AG SULPHIDES HOSTED BY VOLCANOGENIC MASSIVE SULPHIDE DEPOSITS (VMS), IN ALBANIAN OPHIOLITES


HOXHA Sr., Lirim, Consultant Geologist, -, 30 Woodland Rdg, Southwick, MA 01077-9423, lirimhoxha@gmail.com

Cu-Fe sulphides with Zn, Au and Ag known as volcanogenic massive sulphides (VMS) occur as massive, disseminated and vein mineralizations in volcanosedimentary rocks, volcanics, gabbroid plutons, plagiogranite-quartzdiorite intrusions and sheeted dyke complex in the Mirdita Zone ophiolites of Albania.

The Albanian ophiolites of the Mirdita Zone represent remnants of Mesozoic oceanic lithosphere within the Dinaride-Albanian- Hellenide segment of the Alpine orogenic system.

A generalized SW-NE cross-section constitute the Western Mirdita Ophiolites (WMO) lherzolites, thrusted onto mélange and succeeded by gabbroid and MORB-type volcanics, covered by chert and Middle Jurassic mélange. Gabbroid rocks of the Eastern Mirdita Ophiolites (EMO) overthrust the mélange, and succeed upwards with quartzdiorite-plagiogranite intrusions, sheeted dyke complex and SSZ-type volcanics, covered by chert and Middle Jurassic mélange. The section terminates with transgressive Upper Jurassic- Lower Cretaceous shallow water reefslope deposits and carbonates.

The rock units are dismembered and westward displaced by polyphase thrusting tectonics.

In Albanian ophiolites are discovered more than 66 Mt Cu- Fe sulphides, and Cu, Zn, Au, Ag sulphides. 50 Mt (75%) hosted by Eastern Mirdita Ophiolite (mainly volcanics), 11 Mt (17%) by Western Mirdita Ophiolite and 5.3 Mt (8%) as a huge massive Cu-Fe slide in the mélange.

Eastern Mirdita Ophiolite - Are distinguished disseminated copper and massive pyrite ores hosted by the Lower unit of basalt-andesite pillow lavas and the massive and disseminated Cu, Zn, Au, Ag ores, hosted by the Upper unit of the andesite-dacite (rhyolite) volcaniclastics.

Taking into account lithologostratigraphy of sulphide bearing units and polyphase thrusting tectonics are compiled respective sections and metallogenic map, showing clearly substantial increase of reserves.

Western Mirdita Ophiolites- In the Western Mirdita Ophiolites massive pyrite-copper ores are hosted by Middle-late Triassic volcanosedimentary series.

Disseminated droplet-veinlet Cu-Fe sulphides are found at pillow lavas of WMO.

Volcanogen Sulphide deposits in mélange- A large, high-grade lenticular orebody, up to 20 m thick, 300 x 400 m in lateral extent is found in mélange.

Handouts
  • HOXHA L. GSA NE SEC. PENN. 2014..pdf (1.4 MB)