HR: 0800h
AN: T41D-1254    [Abstracts]
TI: Transregional lineament of Central Asia, its magmatism, metallogeny and seismicity
AU: * Sidorova, I
EM: irina_sid@mail.ru
AF: Institute og Geology&Geophysics Academy of science of Uzbekistan, 49,N.Khodjibaeva str., Tashkent, 700041 Uzbekistan
AB: The analysis of the place and role of such large fault as Central Kyzylkum, North Nurata and South Ferghana, Atbashin, which were regarded earlier as separate independent structures led us to the idea that they are parts of a single global structure. We suggest that it should be called "Transregional lineament of Central Asia". Transregional lineament of Central Asia is multisutured long-term, and in the nodal points of some parts it is complicated by deep fault zones of ®Anti Tien-Shan¯ trend.There are large gold ore deposits (Muruntau, Kokpatas, Kumtor) in the intersection of some of these faults. Within the lineament there are 4 mafite - ultramafite associations of different age, that are presented as isolated or combined blocks, zones and regions. The most ancient is ophiolite one (I association). Best of all it is developed in Sultanuvais and Northern Tamdytau, Uzbekistan. The second, rift association of this belt is picrite-gabbro-diabase-alkali-olivine-basalt is widespread within the belt (northern Bukantau, northern Nuratau, northern slope of the Altay ridge).The third association is peridotite-gabbroic. It is represented by the Tebinbulak intrusive of Sultanuvais. Coverings, small stocks, dikes and explosion tubes formed by potassic mafite-ultramafites ore related to much later inter-plate (P-T) occurrences of mafite-ultramafite magmatism (IY association). On Kyrgyzstan's territory the studied lineament is observed as a system of regional deep faults -Atbashi-Inylchek and Southern Ferghana, with which the ophiolite ultramafite-mafite formation is associated. The rocks have the traces of tectonic movements, which can be the ground to regard them as protrusions. Tectonically, the vast territory of Mongolia is divided into two large blocks: northern and southern. This part of the lineament called Transmongolian. This part is week studied-a special investigation was only carried out in its western part - Bulgan fault. Thus, in the presence of linear-stretched sublatitudinal metallogenic belts within the area of the studied transregional lineament in the Central Asian region, the most prospective ore deposits'assemblages are located in the intersection of these belts as deep faults of meridional, north-eastern and north-western trend. The following deposits are situated in such intersection zones: the largest in Eurasia Muruntau gold deposit, a large deposit Kumtor, Kyrgyzstan; and the gigantic class deposit - Ashi in China.Anomalously increased heat flow density (HFD) values both Muruntau deposit (according to our data- up to 85 mW/m2), and for Kumtor deposit (according to E.A.Ljubimova data - up to 130 mW/m2 ) indicate the deep character of dislocations. Interpretation of seismic observations revealed a transregional zone with the width of up to 80 km in the upper part of Kyzylkums crust. The strip is located in the relief of Moho surface, and is discordant to the general trend of premesozoic structures. Abrupt variations of the Moho boundary with vertical movement of up to 10 km are observed in the eastern end of the Issyk-Kul valley and at the boundary of Northern and Middle Tien Shan, along the Nikolaev line. In conclusion we'd like to note that such structures are well-known in American, Australian and other continents.They are recognized as deep structures and served as channels for the heat energy, magmas and fluids to come out of the core and mantle of the Earth. In this connection, activity of these structures are accompanied by the presence of various magamatic, endogenous as well as gigantic ore deposits.
DE: 8110 Continental tectonics--general (0905)
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting