Volcanic complexes and tectonic-magmatic stages of the evolution of the Guyots of the Magellan Seamounts (Pacific Ocean). Communication 2: Tectono-magmatic stages

Abstract

Five tectonic-magmatic stages are distinguished in the evolution of the guyots of the Magellan Seamounts: 1 — Late Jurassic-Early Cretaceous (earliest Cretaceous — ~160–140 (?) Ma); 2 — Early Cretaceous (Late Barremian(?)-Aptian-Albian — ~127–96 Ma); 3 — Late Cretaceous (Late Cenomanian (?)-Turonian-Early Campanian — ~95–76 Ma); 4 — Late Cretaceous (Late Campanian-Maastrichtian — ~74.5–66.0 Ma); 5 — Cenozoic — 66–0 Ma. Each of the tectonic-magmatic stages corresponds to a certain age complex of volcanic rocks of the Magellan Seamount. Tectonic-magmatic stages have different durations and played different roles in the evolution and formation of the modern structure of the guyots of the Magellanic Seamounts. Each of the tectono-magmatic stages characterizes a specific geomorphological space of guyots (base, main part of the edifice, small complicating superimposed structures of the 2-nd order). Each of the tectonic-magmatic stages characterizes a specific geomorphological space of guyots (base, main body, small complicating superimposed second-order structures). On the whole, the tectonic-magmatic stages of the evolution of the Magellan Seamounts are in good agreement with the evolution stages of some other regions of the Pacific Ocean and correspond to the previously established periods of their tectonic-magmatic activation.