Борисов, П. А. Месторождение нефелиновых песков на Кольском полуострове / проф. П. А. Борисов. - Москва : издание Научно-технического управления ВСНХ, 1929 (Нижний Новгород : тип. "Нижполиграф"). - 64 с. : ил., черт., диагр., карт. - (Труды Института по изучению Севера / С.С.С.Р, Науч.- техн. упр. ВСНХ ; № 297 ; вып. 44).

Deposits of Nepheline Sands in the Kola Peninsula. Prof. P. A. Borissov. The field-work of 1927 on the east coast of the lake Imandra, in the centre of the Kola Peninsula stated the occurrence of delta-alluvions in the mouths of alpine rivulets flowing down from the neighbouring Khibine mountains. In the gap between the stations Khibiny and Imandra of the Murman Railway, in the close proximity of the railway, most considerable delta deposits were discovered at three points, namely, in the mouth of the Goltzovka river, at Imandra station; at Gr. Peschany Navolok, in the mouth of the Peschanka, and at L. Peschany Navolok, at the 1288th kilometer of the railway. The drift materials consist exclusively of weathered nepheline-syenite rock, which constitutes in this district the western slopes of the Khibine mountains, and form nephelinic coarse-grained sand walls, 1—1,5 m high above the lake level, washed on the surface by the waves of the Imandra Lake. At other points of the shore alluvial walls of nepheline sands were observed. The sand-walls are situated on the periphery of drift materials, and being a recent product of secondary remaking by the lake wave of the primary delta deposits, are entirely deprived of vegetation. More ancient delta formations, consisting in addition to coarse nepheline gravel of still coarser flint and pebbles of the same composition, are overgrown with a moss. cover with shrubs and wood, all the deposits of nepheline sands occur in the close proximity of the railway. The digging established the invariably uniform composition of nepheline sands to the depth of 2 m; further down they continue to an unknown depth which could not be determined because of the pressure of ground waters (in the given case, of the lake water) and the lack of pumping means. The mineral composition of sands corresponds to that of the base mother rock, i.-e. of massive nepheline-syenites (khibinites) of the western slope of the Khibine mountains in the district under consideration, which are 2,5—3 km distant from the shore of the Imandra lake and in some places approach the shore to a distance of 1,7—2 km, Khibinite as well as its debris carried to the shore contain (approximately in equal quantities) particles of nepheline and of KNa-feldspar (microcline-perthite); both minerals con­ stitute 85— 90% of the composition of syenite forming a coarse-grained (0,5—1 cm) aggregate. In some cases microcline-perthite is prevailing over