『Abstract
Problem of the distribution of clay minerals in water areas of
the World Ocean and their relation to different (humid, arid,
and volcanosedimentary) types of lithogenesis is considered. It
is shown that layer silicates can be used as index minerals for
distinguishing types of lithogenesis under conditions of marine
sedimentation. Humid marine lithogenesis is represented by sediments
of the White, Baltic, Black, and Mediterranean seas. Genetic link
of marine clay formation with soil-climatic zones is clearly manifested
in recent sediments of the World Ocean. Accumulation of statistic
data on the mineral composition of clays allowed us to distinguish
two modes of spatial-latitudinal distribution of clay minerals:
maximal concentrations of illites and chlorites are confined to
high latitudes, whereas kaolinite and smectite accumulate in the
equatorial zone. In the arid lithogenesis, the dependence of clay
formation on drainage areas is practically absent. The whole process
is realized in surficial sediments and bottom waters: under conditions
of intense evaporation, especially in closed water basins, the
concentration of elements in the medium is enough for the synthesis
of layer silicates, such as palygorskite and sepiolite. The processes
were studied based on the Paleogene Fergana Bay and bottom sediments
of the Sea of Aral, as well as DSDP core materials from the Atlantic
(near the western coast of Africa) and Indian (the Arabian Peninsula
area) oceans. The investigation of processes of volcanosedimentary
lithogenesis was carried out within the East Pacific Rise (on
the basis of core materials obtained during cruises of R/V Dmitry
Mendeleev and Akademik Kurchatov). The results obtained
made it possible to establish authigenic (primarily celedonite)
K-Fe mineralization in the most active geothermal zones. The formation
of clay minerals has specific features in each of the studied
(humid, arid, and volcanosedimentary) types of lithogenesis. This
should be taken into consideration during the lithological investigations
and the study of clay mineralogy of past geological epochs. Clay
minerals (particularly, unstable mixed-layered phases) are actively
used as index minerals for paleogeographic and climatologic reconstructions.』
(Introduction)
Clay minerals in areas of humid lithogenesis
Clay minerals in regions of arid lithogenesis
Clay minerals in regions of volcanosedimentary lithogenesis
Conclusions
References