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, Lirim Sr, 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.
Session No. 46
Structural Geology & Tectonics
Monday, 24 March 2014: 4:05 PM-5:50 PM
Lancaster Marriott at Penn Square Heritage Salon E
Geological Society of America Abstracts with Programs. Vol. 46, No. 2, p.90
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Lirim Hoxha, Peter W. Scott and John M. Eyre
The geological setting of volcanogenic sulphide orebodies inAlbanian ophiolites Applied Earth Science (Trans. Inst. Min. Metall. B) March 2005 Vol. 114 B33
Maney Publishing Ltd.
Cu–Fe sulphides with minor Zn, Au and Ag occur as massive, disseminated and vein mineralizations in volcanosedimentary rocks, volcanics and occasionally associated intrusions of a sheeted dyke complex in ophiolites in Albania. The ophiolites form two sub-parallel units, the Western Ophiolite and Eastern Ophiolite Belts, stretching across the country from north-west to south-east, and have mid-ocean ridge and island arc (boninite supra-subduction type) affinities, respectively. The ores have been extensively prospected and were mined until the 1990s.
The Western Ophiolite Belt comprises a volcanosedimentary series, pillow basalts, ultramafic rocks,gabbros and plagiogranites. The most significant orebodies are in volcanosedimentary rocks at Rubik,Palaj-Karme and Porave. The orebodies with massive chalcopyrite–pyrite ores vary in shape occurring between hematised radiolarian chert and tholeiitic basalt pillow lavas. Mapping the shape of the main orebody at Rubik shows a series of mounds comparable to the collapse of ‘black smoker’ chimneys. Massive and disseminated sulphides are hosted by MORB affinity basalts at Kachinar, Derven and Rehova. A geophysical induced polarisation survey has indicated further resources at depth at West Kachinar.
The Eastern Ophiolite Belt consists of a basalt–andesite–rhyolite series cut by a sheeted dyke complex and underlain by quartz diorite–plagiogranite, gabbro, gabbronorite and harzburgite. It includes a 25-km long belt of a significant longitudinal continuity of mineralization between Chafe Mal and Reps. Massive sulphide ores underlain by disseminated veins and stockworks are hosted by a Middle–Upper Jurassic lower basalt–andesite succession at Reps, Spach, Maja e Made, Tuch, Lak Rosch, Paluce and Fushe Arres. Alteration includes chloritization, epidotization, silicification,argillisation, zeolitization and carbonatisation. The Upper Jurassic,upper dacite volcanoclastic, andesite–dacite,boninite succession hosts massive pyrite–chalcopyrite–sphalerite ore underlain by few or no disseminated veins or stockworks at Gurth Spach, Munelle and Chafe Bar. At Perlat, massive ores are in an andesite pillow lava. Induced polarisation anomalies indicate further orebodies at depth in this highly thrusted area. Sulphide veins and other quartz–lode sulphides occur in some gabbros. An unusual orebody at Gjegjan occurs in a tectonic mélange of volcanics, greenschists and amphibolites. Similarities between Albania and other ophiolitehosted volcanogenic deposits at Cyprus and Oman include a clustering of orebodies along the general strike of the ophiolite, the occurrence of massive ores at successive horizons, and the presences of vein, stockwork and disseminated mineralization surrounding and beneath the massive sulphide zones; but, in Albania, ochres and umbers are not found, the age is older and the age-span greater. The Albanian orebodies range in size from 0•3–10•0 Mt. Those in the Western Ophiolite Belt are comparable in size to modern seafloor deposits at ocean ridges. Eastern Ophiolite Belt orebodies are similar in size to others interpreted as having formed in a suprasubduction environment. The Eastern Ophiolite Belt offers the greatest potential for locating future orebodies, possibly beneath thrust planes.
Hoxha., L. and Zaganjori B., 1998., Zonation of sulphide mineralization in the Spac-Gurthspach area (SSZ ophiolites) Albania. In Newsletter of the International Liaison Group on Gold Mineralization, October 1998, N-27, 56-59 (with map generalized section and cross sections)
Hoxha, L. and Zaganjori, B. 1998. Sulphide mineralization zoning of the Spaç-Gurthspaç area (SSZ Ophiolites, Albania): a Case history.
(based on Hoxha, L. and Zaganjori B. 1987 Generalization study of mineral zoning and expected reserves at Musht-Gurth Spac-Spac-Letiten area, 89 pp.) Archives of Albanian Geological Survey). Per. Mineral. 67, 87-93. (With map generalized section and cross sections). Publishing Journal of Dipartamento di Scienze della Terra, Universita "La Sapienza", Rome, Italy
Avxhiu R. and Hoxha L. (1998) Integrated geological-geophysical-geochemical methods for sulphide mineralization explorations, Mirdita ophiolite zone, Albania. Per. Mineral.67: 71-85. Publishing Journal of Dipartamento di Scienze della Terra, Universita "La Sapienza", Rome, Italy
P.Kalino, L.Hoxha, P.Kita, A.Palko and S. Nenaj, 1998 The integrated geological and geophysical exploration for sulphide mineralization at the Rehova deposit (SE Albania). Mineral.(1998), 67, 95-103. Rome
Hoxha, Lirim , 1995, Sulphide mineralizations of Albanian ophiolite’s volcanics (oral presentation at Int. Volcan. Congr. Ankara, 1994). Bul.Shk.Gjeol. Tirana, 1:39-64. ISPGJ, IGJN. 1983
P. LEKA, S. NENAJ and L. HOXHA, 1995: ‘The deep geophysical survey for exploration of sulphide ores’, Bul. Shk. Gjeol., 1995, Nr 2, 69–76.
Hoxha L, Berxhiku P and Daci A (1988) Effects of thrusting tectonics for exploration of sulphide mineralization at Kurbnesh-Tarazh-Perlat region. Bul. Shk. Gjeol..3:7-20
Hoxha, L. 1988 Space-time relationships of sulphide mineralizations with surrounding rocks and outcomes on their zoning at Spaci region, Mirdita, 1988. Buletin i Shkencave Gjeologjike nr 1, 1988 f.13-25. Tirane
Summary
Relied in very detailed exploration of Spaci deposit area (VMS) the most important conclusions are:
There are divided two ore-bearing volcanic sub-formations a) hyaloagglomeratic sub formation with quartz-keratophyre (quartz-andesite-dacite) at upper part of section and, b) basaltic sub formation: basaltic pillow lavas and sheeted dyke complex series belonging to the lower part of the section.
There is distinguished a vertical mineral zoning. At the uppermost part of Hyaloagglomeratic sub formation are hosted sphalerite-chalcopyrite with few copper and sulphur and 1:7 to 1:26 Cu:Zn ratios; at lower parts sphalerite-chalcopyrite-pyrite with high Cu and Zn content and precious metals (Au, Ag) and 1-3 Cu : Zn ratios and pyrite-chalcopyrite ores at the lowermost part, close to the contact with basaltic formations, containing about 35% S, high copper and 2:1 Cu : Zn ratios.
Basaltic subformation hosts pyrite-chalcopyrite and pyrite ores.
Small copper concentrations are located at the contact to gabbro-plagiogranite intrusive rocks
Compared to the exploration done during previous 30 years the last two years the effectivity is increased 5-6 times.
The complex mineralogical composition of Spaci area requires the necessity taking efficient measures by extracting-processing industry in order to minimize losses as much as possible and extracting all constituents.
Studies, Conferences related to exploration of VMS hostded by Albanian ophiolites
L.Hoxha, T.Deda, Gj. Leka, D. Shtjefanaku, S.Gjoni, Ll. Lleshi, 2005, Geological setting, reserves and perspective of Albanian Volcanological Massive Sulphides (VMS).
National Conference organized by Ministry of Industry and Energitics: Strategy of Mining Industry Developmet, based on regional politics for an effective managment of exisisting mineral resources and the new ones possible to be descovered next 15 years. Tirana International Hotel, June, 21st, 2005)
L.Hoxha, T. Deda, Gj. Leka, Ll. Prenga, B.Boshnjaku, D.Shtjefanaku
S.Gjoni, 2005. Geology of Puke-Mirdita District, copper ore reserves resources, and perspective of growth.
National Conference organized by Ministry of Industry and Energitics and Albanian Geological Survey: On the state of Copper Industry, achievements, reactivation and perspective of its development- Fushe Arres, Puke, May 05, 2005.
Lirim Hoxha, Pano Çakalli and Dode Shqefanaku, 2003 Re-evaluation of copper deposits (VMS) hosted by Central Mirdita Ophiolites and prospects for further prospecting and prognozation, Mirdita District, Albania.
Hoxha L., Prenga Ll., Imami S., Daci A., Leka P. 2000., Generalization of geological-geophysical-geochemical exploration carried out at Perlat-Shebe-Kullaxhi area, Mirdita District, Albania.
Hoxha L., Prenga Ll., Imami S., Daci A., Leka P., 2001., Generalization of geological-geophysical-geochemical exploration carried out at Kaçinar-Shperdhaze-Beqiraj-Gjazhde-Verri-Peshqesh area, Mirdita District, Albania.
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Hoxha L., Prenga Ll., T Deda., Imami S., Gjeçi K., 2001., Generalization of geological-geophysical-geochemical exploration carried out at Reps-Spaç-Gurth-Spaç-Qafe Bari-Qafe Mali, Bicaj-Shmi area, Mirdita District, Albania.
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Hoxha L., 1982 Regularities of sulphide mineralization concentration hosted by volcanologic rocks of Mirdita Region and prospects of further investigation (dissertation).Tirana,114 p.
Studies, Conferences and geological reports related to exploration of VMS hostded by Albanian ophiolites
Hoxha L., Prenga Ll., Imami S., Daci A., Leka P. 2000., Generalization of geological-geophysical-geochemical exploration carried out at Perlat-Shebe-Kullaxhi area, Mirdita District, Albania. Archives of Albanian Geological Survey
Hoxha L., Prenga Ll., Imami S., Daci A., Leka P., 2001., Generalization of geological-geophysical-geochemical exploration carried out at Kaçinar-Shperdhaze-Beqiraj-Gjazhde-Verri-Peshqesh area, Mirdita District, Albania. Archives of Albanian Geological Survey
Hoxha, L. and Ndreca, N. 1987 Report on exploration and reserve calculation Spac deposit. Archives of Albanian Geological Survey
Hoxha L., 1982 Regularities of sulphide mineralization concentration hosted by volcanologic rocks of Mirdita Region and prospects of further investigation (dissertation).Tirana,114 p. Archives of Albanian Geological Survey
Hoxha Lirim and Gjeci Kristina Report of reserve calculation Rubiku deposit as 01.01.1981. Rubik 1981. Archives of Albanian Geological Survey
Hoxha, L.1975 Report on exploration and reserve calculation Maja e Madhe deposit. Archives of Albanian Geological Survey
Hoxha Lirim , Koka Adolf, 1970 – Report on results of exploration for Kacinar deposit and reserve calculations. Rubik. 1970. Archives of Albanian Geological Survey