Relationship between Cenozoic structures and polymetallic mineralizations in the central part of the Serbo-Macedonian massif

The geodynamic evolution of the Serbo-Macedonian massif can be reviewed in few geological and geotectonic epochs, but very specific is the Cenozoic evolution from geodynamic, geotectonic, structural, magmatic and metallogenetic point of view. Cenozoic activization at the territory of the FYR of Macedonia enclosed the most complex geotectonic units such as Vardar zone and SMM. Its occurrence is mainly along fissures of general NW-SE direction and activated meridian cracking zones and faulting systems of general NE-SW direction. In such conditions came to complete redistribution of the lineament structures network when on the main direction of Mesozoic structures NW-SE (340º) occurred fault system of the same direction but slightly different angle (320º). Striking transcurrent faults can be recognized from air and satellite pictures, striking in the same direction as the zone of activation, as well as systems of smaller parallel faults, systems of diagonal jagged faults and systems of straight, tension faults. A special characteristic of the zone of autonomous activation are their numerous ringlike structures. This activization significantly contributed to the localization of the Cenozoic mineralizations within the Eastern FYR of Macedonia. The disruption structures of of NW-SE direction control three major Cenozoic metallogenetic zones (two of them characterized by the Oligocene-Miocene magmatism and mineralization in the Kratovo-Zletovo and Bucim-Damjan-Borov Dol ore regions and third characterized by Miocene volcanics and related mineralization at the Osogovo ore region). Logical metallogenic analysis have confirmed that megastructures in the Tertiary autonomous activation zone correspond to the ore districts and coincide with the centres of magmatic activity, while the distribution of mineral deposits in them is found to be distinctly laterally zoned. The lesser ringlike structures correspond to the structure of the ore fileds or mineral deposits, as it is a case with the Bukovik-Kadiica polymetallic ore system. Especial feature within these structural elements are the faulting structures with general direction NE-SW which relicts are saved up to date. They have controled seismic zones and have shown influence to the loalization of magmatic bodies and ore mineralization on places where structures of NW-SE cross cut. These types of structures are common in so called wide zones of relaxation. After the activization of Cenozoic faults followed stage of formation of pericline structures and systems of concentric structures of volcanic type (numerous volcanic calderas in the Kratovo-Zletovo volcanic area). The Bukovik-Kadiica ore district, characterized by complex polymetallic mineralization, is located in the most eastern parts of the Besna Kobila-Osogovo-Tassos metallogenic zone. Determination of tectonic elements was done by different methodologies: generalization of horizontals, river networks, interpretation of satellite imagery etc. From north to the east, the lower part of the area, has been surrounded by the raised arc (1600-1700 m). Radial and radial-centrifugal forms allowed determination of two crossed oval structures: southern and northern. Higher points, erosion study and alluvial accummulation are pointing our to a slope-like development with characteristic valleys and slopes on the southern oval structure and raise of the northern oval structure. Intersection of the oval forms has been complicated by the ring structure 3.5 km in diameter. Its central part overlaps with the independently raised Bukovik (1700 m). Around the raised area there is a depression belt, which has been articulated with the highest parts of the adjacent river valleys. To the east, outer side of the structure has been limited by raised arc. The Bukovik ring structure has been located within the intersection of orthogonal system of fissures determined on the linear tectonic elements of the recent relief. Field observations, desk studies, satellite imagery, metallogenic features, confirmed that morphostructural parameters of the Bukovik- Kadiica area are characterized by structures of two general directions (NW-SE and NE-SW). Also, this study has shown that mineralization was closely associated to the intersection knots of major structures.