On Volganism and Tectonics in the Evolution of the Guyots of the Magellan Seamounts (Pacific Ocean)

Abstract

This report is devoted to the analysis of original geological materials on the Magellan Seamounts in the Pacific Ocean, obtained by the authors in numerous voyages of R/V ʺGelendzhikʺ. This chain of guyouts does not have a common volcanic basement and apparently was formed in the second half of the Early Cretaceous on the oldest (middle-last Jurassic) fragment of the Pacific plate. The main points of view on the genesis of the Magellan Mountains are as follows: either they originated at the crossing of the transform fractures, or the Pacific plate moved them from the southern hemisphere to their present-day position. Because of their high degree of study, the Magellan Seamounts are one of the key sites for understanding the mechanism of the origin of linear chains in the ocean. A comprehensive analysis of new geological on the Magellan Seamounts has established the important role of magmatism and tectonics in the formation of the modern morphological shapes, sedimentation and influence on the paleooceangraphy. The periodic renewal of these processes from the Early Cretaceous to Late Cenozoic can be traced in the cyclicity of sedimentation, the permanent growth of ore crusts and the formation of secondary volcanic domes and cones.