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Geological processes in the Khibiny

Beginning of the Quaternary period of about 1 million years ago was accompanied by repeated advance of glacier from Scandinavia through the Kola peninsula to Russian plain. Huge masses of continental ice during movement ploughed the crystalline rock outcrops, flattened the surface, cut the deep furrows and took away large amount of fragmental rock materials. Due to climate warming the glacier melted and left piles of friable deposits - so called moraine and formed characteristic ice landscape.

Geological processes in the Khibiny

Narrow and long moraine ridges and eskers were formed in the area of former rivers, on the glacier surface, oval-shaped hills and sowbacks consisting of boulders, gravel and rockstone, sand, silt and clay. Such sediments cover almost the whole territory of the Kola peninsula and the northern part of the Russian plain. Moraine thickness in the lowlands can reach 100-200 meters. Traces of the last three glacier ages were preserved: the Moscovian epoch - 200 thousand years ago, Low Valdayskaya - 80 thousand years and Upper Valdayskaya - 23 thousand years ago. The last one ended 9 thousand years ago. Sediments of all previous continental glacier invasions were not confirmed as they are completely destroyed by the following glacier epoch.

Earthquakes occurred more than once in the Kola North. The earliest established took place in town Kola in November 1758, and then was numerously repeated both there and in other areas of Lapland - the former name for Kola region and North Karelia in town Kem'. Based on evidence earthquake shocks were accompanied by noise, lasted several minutes and perceived. The soil moved, buildings reeled, the furniture moved, houseware fell. According to scientists' opinion the Kola region is not a hazardous in terms of earthquakes. By the way, the last earthquake took place in the area of Kirovsk and Apatity in 1988.

Information stated above is about natural geological phenomena. But earthquakes can be mining-induced as there are several mining enterprises in our region. During mining works in the open-pits and mines large masses of rocks are extracted - up to several hundred million tons per year. This disturbs the natural balance. There are worked-out areas - huge pits instead of open-pit mines, numerous underground workings, there are waste stockpiles, tailings from concentration plants of several billion tons. It should be noted released zones - worked-out spaces of subsurface and excess load zones - mining wastes are locally near thus increasing many times the natural balance, changing geodynamic regime of the rockmass, provoking real hazard of mining-induced, i.e. man-made earthquakes.

Therefore, seismic activity of the Kola North is provided both natural and mining-induced reasons. No wonder that there is a seismic station in Kirovsk where the largest mining enterprise - «Apatit» is located that annually register underground earthquakes. Previously they were registered 3-5 times less.

Geological development of the Earth never stops. In modern age human activity is an active geological force. It is very important to make it reasonable following the rule - «Do no harm!»

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