stripes
Bereshite (see locality 2) sheets and cross-cutting dykes have been observed among nappes of diabase porphyry and basalt in the northwestern part of the Minusinsk trough. Bereshite is notable for containing segregations of idiomorphic nepheline phenocrysts having diameters from 2-3 mm to 3-5 cm. Their abundance is widely variable and they are usually partially or completely replaced by secondary minerals such as cancrinite, zeolite and hydromica. Small euhedral phenocrysts of augite also occur. These rocks, besides nepheline, also contain clinopyroxene of varying composition (titanaugite, aegirine-augite), plagioclase (labradorite to oligoclase), and sometimes olivine, as well as accessory apatite and Fe-Ti oxide minerals. The chemical composition of these rocks can be found in Luchitsky (1960).
KONONOVA, V.A. and SHANIN, L.L. 1973. Application of the radiogenic argon method on nepheline for age determinations of alkaline complexes. In G.D. Afanas'ev (ed) Geologic-radiologic interpretation of contradictory age determinations.40-52. Nauka, Moscow.
LUCHITSKY, I.V. 1960. Volcanism and tectonics of Devonian depressions of the Minusinsk intermontane trough. Publishing House of the USSR Academy of Sciences, Moscow. 275 pp.