Genetic relationship between karst bauxites and chemogenic eluvium
Title:
Genetic relationship between karst bauxites and chemogenic eluvium
Author:
Chukhrov, F. V.
Appeared in:
International geology review
Paging:
Volume 19 (1977) nr. 9 pages 1009-1020
Year:
1977-09
Contents:
Data from Yugoslavia are of great interest in determining the genetic relationships between sedimentary karst bauxites and chemogenlc eluvium. Our information leads to the following generalizations on the position and genetic history of the Yugoslavian bauxites: 1) deposition of a significant part of the bauxites was preceded by the formation of sedimentary clays on the karst surface of carbonate rocks; 2) the clays are overlain by aphanitlc bauxites, formed during the phase of sedimentogenesis; 3) the bauxites are predominantly red and, as a rule, contain many oxides of trivalent iron; 4) at the base of the bauxite-bearing sequences, and also segregated from them, are rocks of the refractory-clay type; 5) data are lacking on the occurrences of fragments of bauxltlzed silicate rocks in the Yugoslavian bauxites, which serves as one of the proofs of the lack of grounds for assuming that free alumina originated from weathering crusts; 6) the uniform dense construction of the bauxites indicates the finely dispersed nature of the silicate particles, which served as sources of free alumina in the karst bauxites; 7) the uniformity of the red color of the bauxite material of various deposits and its homogeneity in the bauxites, which have not been subjected to the effects of lacustrine-paludal waters, are evidence of the ingress into the karst depressions of bauxite material already colored by iron oxides. Under conditions of less intense drainage, chemical erosion of the carbonate rocks led to the formation of terra rossa. —Author.
Journal description