Regional Geological Studies as a Basis for Tectonic Demarca of the Oceanic Floor

摘要

The geological structure of some areas of the Atlantic Ocean floor is characterized in context of its tectonic demarcation. The transform fracture zones and the crest zone of the Mid-Atlantic Ridge were the study targets. The studies were performed at medium- and large-scales by expeditions of the Geological Institute of the Russian Academy of Sciences. Geological and structural maps of typical areas are presented in the paper. This line of investigation is vital for recognition of the tectonic complexes that determine the structure of the oceanic floor and, hence, its tectonic demarcation. The specific examples demonstrate that this approach opens broad avenues for setting and solving general problems of tectonics, magmatism, and metallogeny of the oce anic floor. Currently, the pace of medium- and large-scale regional geological studies in oceans is very low and, consequently, very little has been done in this respect so far. This is particularly evident from comparison of the total ocean area and the areas where such studies have been performed. Progress in regional geological studies is the most topical task of oceanic geology.