By the priority parameters unders conditions of the up-to-date market – decorative properties and the output of blocks – the geological-recoverable types of the facing stone deposits are selected among known ones on Karelian Isthmus. There are indicated parameters most important for geologic-economical estimation of those deposits, and made for methods of geological-exploration work, with examples of using the facing stones from currently mined deposits.
The peculiarities of are considered in terms of mica-bearing pegmatites of the Karelian, Kola and Mama and Vitim mica-bearing provinces and chamber pegmatites of Central Kazakhstan. Special attention is paid to the influence of physical and mechanical properties of enclosing rock on the shape and occurrence of pegmatite bodies and their association with post-folded faults.
The prerequisites for the development of the deposits, the previous studies and the current state of Karelian Isthmus facing stone sources as well as their comparison with those of other regions of Northwestern Federal Districts of Russia are considered. The objects for top-priority geological prospecting are determined.
A method is suggested to calculate theoretical (forecasted) value of expected output of commercial blocks at the facing stone deposits, which is based on 3D modeling with application of the MICROMINE mining-geological information system.
The methods of determining decorative properties of facing stone, fracturing and yield of blocks in the deposits of the Karelian Isthmus have been analyzed. The form of representation of a deposit in the catalog illustrating varieties of facing stone of the region is developed. The method of determining the theoretical (predicted) yield of blocks by the equation of dependence of natural blocks yield on the area specific fracturing of steeply falling and inclined fractures, taking into account the losses during the extraction of commercial blocks, is proposed.
Under the term ornamentality is meant a set of external properties of the rock, including its coloring and pattern. According to methodical instructions the "Scale of evaluation of decorative effect of facing granite" was made. According to this scale 10 experts-geologists estimated 20 polished samples of granite, each of which was classified as one of four classes of decorative effect. During the survey it was found that many of the parameters for assessing the decorativeness require refinement for a more unambiguous definition.
Natural processes with negative impacts on the natural environment and human life safety are widely manifested on the territory of Russia: endogenous (seismic hazard) and exogenous (mudflows, avalanches) geodynamic phenomena, as well as the accumulation of anomalous concentrations of toxicants in geological bodies.
