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Sedimentation history of the Northern Guaymas rift in the Gulf of California

Author(s): S. Sarkar GEOMAR, Helmholtz Centre for Ocean Research, Kiel, Wischhofstrasse 1-3, 24148 Kiel, Germany
C. Berndt GEOMAR, Helmholtz Centre for Ocean Research, Kiel, Wischhofstrasse 1-3, 24148 Kiel, Germany
C. Hensen GEOMAR, Helmholtz Centre for Ocean Research, Kiel, Wischhofstrasse 1-3, 24148 Kiel
C. Mortera-Gutierrez Instituto de Geofísica Universidad Nacional Autónoma de México, Ciudad Universitaria Delegación Coyoacán, 04510 México D.F., México
S. Muff GEOMAR, Helmholtz Centre for Ocean Research, Kiel, Wischhofstrasse 1-3, 24148 Kiel, Germany
J. Karstens GEOMAR, Helmholtz Centre for Ocean Research, Kiel, Wischhofstrasse 1-3, 24148 Kiel, Germany
R. Behrendt GEOMAR, Helmholtz Centre for Ocean Research, Kiel, Wischhofstrasse 1-3, 24148 Kiel, Germany
C. Böttner GEOMAR, Helmholtz Centre for Ocean Research, Kiel, Wischhofstrasse 1-3, 24148 Kiel, Germany
W. Chi Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan, R.O.C.
D. Kläschen GEOMAR, Helmholtz Centre for Ocean Research, Kiel, Wischhofstrasse 1-3, 24148 Kiel, Germany
M. Moser GEOMAR, Helmholtz Centre for Ocean Research, Kiel, Wischhofstrasse 1-3, 24148 Kiel, Germany

The Guaymas Basin, Gulf of California is a young, narrow, thickly sedimented (- 5 km of sediments intercalated with rift-related sills and dykes) transtensional basin with two separate spreading centers connected by transform faults. An integrated analysis of high-resolution multibeam bathymetry data and several high-resolution two-dimensional reflection seismic profiles reveal the variations in rift morphology, sea floor topography, sedimentation history and hydrothermal activity in both the northern and southern rift segments. There are two main mass transport deposits in the basin- (1) an extensive mass transport deposit covering much of the eastern side of the Guaymas Basin and the northern central rift graben that was emplaced during a late Quaternary (ca 90-60 kyr BP) and was probably caused by relative sea level fall, rapid sedimentation and slumping at the outer fringe of the prograding Yaqui Delta, and (2) a separate postglacial (Holocene) mass transport deposit that was emplaced within the narrow central graben in the northern rift segment, which was probably caused by transform fault movements at the junction between the central rift graben and the adjoining northern transform margin. The mass transport deposits were downfaulted inside the central graben and overlain by recent turbidites. Hydrothermal activity is widespread in both rift segments. The mass transport deposits overlie most of the hydrothermal systems and potentially hinder fluid expulsion in the southern part of the Guaymas Basin as much fewer cold seeps are observed here than in the northern part of the basin. Although the source of the mass transport deposits is outside the bathymetry coverage it seems they are sourced from Jess than 1 km water depth on the Yaqui Delta. The large size, shallow source region and the fact that the Gulf of California is a confined basin suggest that a major submarine landslide could have caused a tsunami. lnstitute ofEarth Sciences, Academia Sinica, Taipei, Taiwan, R.O.


Title:
Sedimentation history of the Northern Guaymas rift in the Gulf of California
Type:
Oral
Origin:
Academia
Day:
3
Lead author last name:
Sarkar
Lead author first name:
S.
Affiliation(s):
GEOMAR, Helmholtz Centre for Ocean Research, Kiel, Wischhofstrasse 1-3, 24148 Kiel
Country:
Germany
Abstract status:
withdrawn
UID:
48