An example of multicomponent magnetization in welded tuffs: A case study of Upper Cretaceous welded tuffs of eastern Russia

Four distinct components of natural remanent magnetization were isolated from a single site in welded tuffs in the Upper Cretaceous Kisin Group of the Sikhote Alin mountain range, Russia. In order to contribute toward a basis for an interpretation of multicomponent magnetization, rock magnetic experiments were performed on the welded tuffs. All four magnetization components essentially reside in magnetite. The lowest-temperature component up to 300 °C (component A: D = 349:3°, I = 60:9°, α₉₅ = 7.3°, N = 7) is a present day viscous magnetization. The third-removed component (component C: D = 41.4°, I = 51.8°, α₉₅ = 3.5°, N = 8), isolated over the temperature range of 450-560 °C, is a primary remanence. The second- and fourth-demagnetized components (component B: D = 174:7°, I = -53.1°, α₉₅ = 21.2°, N = 3 and component D: D = 188.1°, I = -64.5°, α₉₅ = 4.0°, N = 8. respectively) are secondary magnetizations related to a thermal event in Sikhote Alin between 66 and 51 Ma. Components B and D were acquired through different remagnetization processes. Component B is ascribed to a thermoviscous remanent magnetization carried by single-domain magnetite, and component D is a chemical remanent magnetization.