The morphology, processes, and evolution of Monterey Fan: a revisit

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Abstract

Long-range (GLORIA) and mid-range (TOBI) sidescan imagery and seismic-reflection profiles have revealed the surface morphology and architecture of the complete Monterey Fan. The fan has not developed a classic wedge shape because it has been blocked for much of its history by Morro Fracture Zone. The barrier has caused the fan to develop an upper-fan and lower-fan sequence that are distinctly different from one another. The upper-fan sequence is characterized by Monterey and Ascension Channels and associated Monterey Channel-levee system. The lower-fan sequence is characterized by depositional lobes of the Ascension, Monterey, and Sur-Parkington-Lucia systems, with the Monterey depositional lobe being the youngest. Presently, the Monterey depositional lobe is being downcut because the system has reached a new, lower base level in the Murray Fracture Zone.


A five-step evolution of Monterey Fan is presented, starting with initial fan deposition in the Late Miocene, about 5.5 Ma. This first stage was one of filling bathymetric lows in the oceanic basement in what was to become the upper-fan segment. The second stage involved filling the bathymetric low on the north side of Morro Fracture Zone, and probably not much sediment was transported beyond the fracture zone. The third stage witnessed sediment being transported around both ends of Morro Fracture Zone and initial sedimentation on the lower-fan segment. During the fourth stage Ascension Channel was diverted into Monterey Channel, thereby cutting off sedimentation to the Ascension depositional lobe.

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Additional publication details

Publication type Book chapter
Publication Subtype Book Chapter
Title The morphology, processes, and evolution of Monterey Fan: a revisit
DOI 10.1017/CBO9780511529481.017
Year Published 2010
Language English
Publisher Cambridge University Press
Publisher location New York, NY
Description 28 p.
Larger Work Type Book
Larger Work Subtype Other Government Series
Larger Work Title Geology of the United States' seafloor: the view from GLORIA
First page 193
Last page 220
Country United States
State California
Other Geospatial Monterey Bay