PRIMARY INDICATORS OF ASSOCIATIONS OF ROCKS OF THE UDOKAN SERIES

Abstract

The mineralogical-geochemical properties of the rocks, together with their lithology, can be used to reconstruct the original color of the rocks of the Udokan series. Originally red complexes corresponding to certain of the continental phases identified by YU.V. Bogdanov et al. and L.F. Narkelyun et al. are shown. The paleo-red beds are interstratified with originally gray shallow-sea deposits. Copper showings in the Udokan series have a definite geochemical position: as in the sedimentary sequence of the Phanerozoic, they gravitate to the zone in which originally red sequences grade into by originally gray sequences, or are directly associated with the originally red sequences. In the latter case, the copper-bearing rocks contain an impregnation of pyrite in addition to magnetite. The pyrite either saturates the finest-grained rocks, which are interstratified with magnetite-containing sandstone, or forms zones of pyritization in the latter, which seem to indicate the remains of change of color of red rocks that occurred in ancient times.