whose compound minerals are sequentially deposited. They are represented by gneiss, mica schists, and amphibolite. In many places granite passes into granite–gneiss. There are marbles and amphibolites formed in the Paleozoic over 250 million years ago and subsequently elevated during the Tertiary period. The coarse–grained granites are the dominant rocks forming almost two–thirds of the area of the Rila's higher parts. Rile was subjected to glaciation during the Pliocene and the Pleistocene. Its modern Alpine relief was formed during the last Würm glaciation some 10–12 000 years ago, when the snowline of the mountain was 2,100–2,200 m. The glaciers reached elevations as low as 1,200 m. Above this boundary, the glaciers radically altered the existing relief, forming deep cirques, pyramidal peaks, steep cliffs, long U-shaped valleys, moraine fields and other glacial forms. On the slopes of some valleys such as those of the rivers Beli Iskar, Maritsa and Rilska there are hanging glacier valleys — tributary valleys located higher than the main ones. The bottom of cirques are often occupied by glacial lakes. As a result of the weathering, scree formations of varied nature have been accumulated. In the south-western foothills of Rila the Stob Earth Pyramids were formed under the influence of erosion. The staged elevation of the mountain during the geological eras and the large range of vertical folds have led to the formation of four denudation levels of distinct age, height and range. The oldest Early Miocene level encompasses the highest sections of the mountain with an elevation between 2,800 and 2,400 m. It represents practically leveled terrain with gently folded surface, formed in the place of ancient forest massifs. The next Late Miocene level, the young Miocene, is situated on the main side ridges with an elevation between 2,600 and 2,300 m. The third level formed during the Early Pliocene has an elevation of 1,800 and 1,600 m. The Late Pliocene level occupies areas with an elevation of up to 1,300 m. There are two summits above 2,900 m, Musala and Malka Musala. Some of the highest peaks are: Musala, Malka Musala, Irechek, Bezimenen (Noname), , between Musala and Aleko Deno, Studenia Chal, Golyam Bliznak, Malak Bliznak, Mancho, Pesokliva Vapa, Ovcharets (Yurushki Chal), Marishki Chal, Golyam (Big) Kupen, Malyovitsa, Sreden (Middle) Kupen, Cherna Polyana, Aleko, Rilets, Golyam Skakavets, Popova Kapa, Lopushki Vrah, Otovishki Vrah, Yosifitsa, Lovnitsa, Kanarata, Pogledets, Draganitsa, Orlovets, Aladzha (Pastri) Slap, Vodni Chal, Malak