stripes
The Ponoiskii occurrence has an area of about 700 km2, only part of which is shown on Fig. 9, and is located in a zone in which northwesterly- and northeasterly-trending faults cross. It is formed of a series of circular ring-dykes and arcuate dykes, situated in the Archaean basement. In the eastern part of the intrusion granites have been emplaced into the nucleus of a dome-shaped anticlinal structure, thus forming a stratiform body. The granites generally contain aegirine and arfvedsonite and are well foliated. The main rock-forming minerals are quartz, microcline, albite, aegirine and alkaline amphibole with the principal accessories zircon, titanite, apatite, monazite and minor astrophyllite and fluorite. A statistical analysis of the rock chemistry of Ponoiskii was undertaken by Ozhogin (1969a) who also studied zircon (Ozhogin, 1969b).
BATIEVA, I.D. 1976. The petrology of alkaline granitoids of the Kola peninsula. Nauka, Leningrad. 223 pp.
BATIEVA, I.D. et al. 1985. Magmatic formations of the north-eastern part of the Precambrian Baltic Sheild. Nauka, Leningrad. 175 pp.
*OZHOGIN, V.A. 1969a. Statistical processing of silicate analyses for the upper Ponoy alkalic granite and its host rocks (Kola peninsula). Doklady Akademii Nauk SSSR, 182: 156-9.
*OZHOGIN, V.A. 1969b. Zircon of the upper Ponoy alkalic granite, Kola peninsula, as an indicator of its origin. Doklady Earth Science Sections. American Geological Institute, 182: 159-62.
PUSHKAREV, Yu.D. 1990. Megacycles in the evolution of the crust-mantle system. Leningrad. Nauka, Leningrad. 300 pp.
