Cenozoic weathering crusts and conditions of their formation at the South of the Far East

Abstract

Three weathering crusts of different age are distinguished at the South of the Far East, those related to Cenozoic regional stages of planation, i.e. Middle-Late Eocene, Middle Miocene and Early-Middle Pliocene. Paleo-geomorphic environments of the crusts formation indicate the weathering process all over the territory, both at ancient plains and mountains, however final planation of the territory was not achieved. During Eocene the weathering processes took place under climatic conditions similar to those of the present-day wet subtropics. The similar environment of chemical weathering existed also at Middle Miocene.

At plains and within basins at piedmonts and high plains residual crusts and redeposited waste are covered with coalbearing deposits, at mountains crusts being mostly preserved under lava sheets. Eocene and Miocene landscapes were likely favourable to hypergenous ore formation, including bauxites.