Monterey Bay Aquarium Research Institute

Mendocino Fracture Zone Cruise
August 24 - 31, 2000
Over 300 km off the California-Oregon Coast
Cruise Description


Introduction

This cruise is a collaborative effort to study the tectonic history and structure of the northernmost extent of the San Andreas System, as exposed along the Mendocino Fracture Zone. The MBARI program, lead by Debra Stakes, will focus on the lithology of uplifted oceanic crust. The NURP-funded Oregon State Program, led by Robert Duncan joined by Martin Fisk and Anne Trehu, will focus on the tectonic history of the Gorda Escarpment, and its relationship to the plate margin evolution. The western portion of the Mendocino Fracture Zone (the Menocino Ridge) contains uplifted pieces of oceanic crust and some evidence of past subareal exposure. The eastern portion of the Mendocino Fracture Zone is called the Gorda Escarpment. At this contact, a recent seismic cruise imaged uplifted pieces of basement of unknown lithology capped by deformed sediments of unknown age. To the east, drainage channels carved into the face of the Gorda Escarpment appear to begin at the same depth where layers of buried hydrate disappear from the seismic record. The seven dive days of this cruise will explore the deformed ocean crust of the Mendocino Ridge, the uplifted contact between the Pacific and Gorda plates and the enigmatic channels on the easternmost Gorda Escarpment.

 

Click on the links to the left and the picture below to find out more about this exciting cruise!

 


All images created by K.A. Salamy © MBARI, August 2000