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Date submitted2015-10-08
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Date accepted2015-12-11
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Date published2016-08-22
Rare metal granites in the structures of the Russian sector of Pacific ore belt
- Authors:
- V. I. Alekseev
Data are presented on the geology of areas of rare metal granites proliferation in the Russian sector of the Pacific Ore Belt that make one take a fresh look at the East Asian granitoid area to update its metallogeny. History is reviewed of studying rare metal granites of the Russian Far East. As a rule, these are found in the vicinity of major tungsten-stanniferous ore deposits, except much later than discovering the former, at the stages of their assessment and survey. Rare earth granites are usually missed by the geologists during the early stages of regional geological surveys due to their small size, weak eroding and external similarity with earlier granites. Using the examples of the Central Polousny, Badzhal and Kuyviveem-Pyrekakay regions the structural and geological conditions are characterized of localization of rare metal granites. Comparative analysis of geological situations made it possible to formulate the areal character of manifestation of rare metal granites; their confinedness to late Mesozoic orogenic arched uplifts of bogen structures above deep granitoid batholiths; positioning in the areas where longitudinal and transversal deep laying faults cross; gravitation to the environs of pre-Cambrian median masses.
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Date submitted2009-07-17
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Date accepted2009-09-18
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Date published2010-04-22
Transformation of the form and angular parameters of rock movement processes with depth at ore deposits
- Authors:
- A. G. Shadrin
- M. A. Shadrin
It was established the increase of movement angles with mining depth and the mechanism of forming the stable natural arching in underground mining of ore deposits. The conditions and parameters of forming the stable natural arching were determined, under which the zone of dangerous deformations localizes inside the ore mass and does not manifest itself on the earth surface. The nomogram for analytical determination of the rock movement angles was developed, and the table was drawn up of the natural arching conditions with due account of main mining-and-geological factors of ore deposit occurrence and its mining.
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Date submitted2008-10-21
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Date accepted2008-12-12
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Date published2009-12-11
Assessment of stress-strain state of temporary support during constructhion of station tunnels of the metro
- Authors:
- V. A. Maslak
In-situ testing technique of temporary support is given. The values of stress and normal force in arch and sides of steel support are shown. Determination of vertical load magnitude is done. It was determined that vertical load on support decreases by 1,54 times, if lag of support installation from the face is16 m.