A neogean orogenic tectonics of East Macedonia (with use of the morphostructural analysis)

It was disclosed that structures of modern relief of Eastern Macedonia reflect the tectonic forms of Neogene period. Active oreforming prosesses took place in that period. The neogene structure forms was reconstructed on the basis of morphostructural metodh. This structures have major role for control of metalogenic units. Three ranges of ring structures and zones of linear dislocations, that are orecontrolling structures, were disclosed on the territory of Eastern Macedonia

Tectonic Position of the Alshar Au–As–Sb–Tl Deposit, Macedonia

During the second half of the 20th century, several dozen large and medium deposits of disseminated pyrite–marcasite ores with total gold reserves of more than 6000 t and annual gold production of ~200 t were found in the Basin and Range Province, Nevada, United States [1, 2]. This unique gold district is termed as the Carlin trend. The limited development of the Carlintype mineralization in other gold districts of the world is presently a debated issue. Naturally, each Carlin-type mineralization inferred beyond Nevada requires detailed investigations. In 2004, we began to study the Alshar deposit with Carlin-type mineralization together with Macedonian geologists [3]. The Alshar deposit is a large object in terms of Tl reserves and a medium reserve in terms of inferred Au reserves [3, 4]

The Alshar Epithermal Au-As-Sb-Tl Deposit, Southern Macedonia

The results of tectono-metallogenic, geological-structural, mineralogical, isotopic and thermobarogeochemical studies at the Alshar deposit and in the adjacent area are discussed. The data obtained show that the gold mineralization at the deposit is similar to that observed at the Carlin-type deposits in the western United Stales. Similar characteristics include the Au-As-Sb—Tl-Hg geochemical assemblage; low Pb, Zn, Cu, and Ag contents in ore; widespread jasperoid and argillic metasomatic alterations of host siliciclastic-carbonate sedimentary rocks; and the spatial relations to fault zones. At the same time, the Alshar deposit differs from the Carlin-type deposits by the following features: (1) Pliocene age of mineralization. (2) expansion of mineralization over younger volcanics, (3) a high Tl grade in ore, and (4) localization of the ore field in a long-lived central-type magmatic structure. The results obtained can be used as an exploration model