Digital Commons Network^™

Determining The Subsidence Rate Of The Cascade Seamount Using Strontium Isotope Stratigraphy, Sarah L. Vorsanger

Theses and Dissertations

The Cascade Seamount is a wave-planated feature located on the microcontinent of the East Tasman Plateau (ETP). The minimum subsidence rate of the Seamount and the ETP can be estimated by dividing the present-day depth of the wave-cut surface (640 m) by the age of Cascade Seamount basalts as determined by potassium-argon (K-Ar) dating (33.4 and 36 Ma). This approach yields a subsidence rate of 18 m/Myr. However, a significantly more rapid subsidence rate of the ETP since the Eocene-Oligocene transition has been proposed based on sedimentological and biostratigraphic techniques. The late Eocene paleodepths determined by Stickley et al. (2004) …