Volcanic Complexes and Tectonomagmatic Stages in the Evolution of Magellan Seamount Guyots (Pacific Ocean). Message 2: Tectonomagmatic Stages

Abstract

There are five tectonomagmatic stages in the evolution of Magellan Seamount guyots: 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–Maastrichian, ∼74.5–66.0 Ma); 5, Cenozoic, 66–0 Ma. Each of the tectonomagmatic stages corresponds to a specific age complex of volcanic rocks of the Magellan Seamounts. Tectonomagmatic stages have different durations and played different roles in the evolution and formation of the modern structure of Magellan Seamount guyots. Each of the tectonomagmatic stages characterizes a specific geomorphological space of guyots (base, main part of the structure, small complicating overprinted second-order structures). In general, the tectonomagmatic stages in the evolution of the Magellan Seamounts agree well with the stages of the evolution of some other regions of the Pacific Ocean and correspond to the earlier established periods of their tectonomagmatic activation.