Composition of rocks and minerals from the Cape Verde Fault Zone

Results of comprehensive geological, geophysical and geochemical studies carried out in the Cape Verde Fracture Zone (Central Atlantic) during Cruise 9 of R/V ''Antares'' (1990-1991) are published in the book. Detailed characterization of various bedrock complexes (ultrabasites, gabbroids, dolerites, basalts, metamorphic rocks) is given. Geological conditions of newly found hydrothermal mineralization in the area are described. Problems of ore melts are under consideration. New data on hydrochemical anomalies and heat flow are given. The book contains original materials on sedimentary formations of the area.

(Table 1) Chemical composition of buried manganese noduls and host sediments of ODP Hole 138-854C

Two manganese (Mn) nodules were found in upper Miocene sediments in Hole 854C at a depth of 32.12 mbsf (Samples 138-854C-5H-1,0-2 cm, and -6H-1, 2-4 cm). In structure and composition, the lower nodule is similar to the Pleistocene surface nodules associated with radiolarian ooze from the Clarion-Clipperton Nodule Province. The upper nodule resembles those occurring on pelagic clay from the northern margin of that province.