Serpentinite-breccia landslide deposits generated during crustal extension at the Iberia Margin

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doi: 10.2973/odp.proc.sr.149.226.1996
Author(s): Gibson, Ian L.; Milliken, Kitty L.; Morgan, Julia K.
Author Affiliation(s): Primary:
University of Waterloo, Department of Earth Sciences, Waterloo, ON, Canada
Other:
Rice University, United States
Ocean Drilling Program, United States
Université Pierre et Marie Curie, France
Dalhousie University, Canada
Universidad de Granada, Spain
Université de Nantes, France
Florida State University, United States
Universidade de Aveiro, Portugal
INTERGEOS, Netherlands
University of Waterloo, Canada
Lamont-Doherty Earth Observatory, United States
University of Tokyo, Japan
GEOMAR, Federal Republic of Germany
University of Leicester, United Kingdom
University of Texas at El Paso, United States
University of Michigan, United States
Universität Kiel, Federal Republic of Germany
Cornell University, United States
California State University, United States
Iowa State University, United States
University of Maryland System, United States
Open University, United Kingdom
University of California, United States
University of Texas at Austin, United States
University of Washington, United States
Volume Title: Proceedings of the Ocean Drilling Program; scientific results, Iberia abyssal plain; covering Leg 149 of the cruises of the Drilling Vessel JOIDES Resolution; Balboa Harbor, Panama, to Lisbon, Portugal; sites 897-901, 10 March-25 May 1993
Volume Author(s): Whitmarsh, Robert B.; Sawyer, Dale S.; Klaus, Adam; Beslier, Marie-Odile; Collins, Eric S.; Comas, María Carmen; Cornen, Guy; de Kaenel, Eric; Pinheiro, Luis de Menezes; Gervais, Elisabeth; Gibson, Ian L.; Harry, Dennis L.; Hobart, Michael A.; Kanamatsu, Toshiya; Krawcyzk, Charlotte M.; Liu, Li; Lofts, Jeremy C.; Marsaglia, Kathleen M.; Meyers, Philip A.; Milkert, Doris; Milliken, Kitty L.; Morgan, Julia K.; Ramirez, Pedro; Seifert, Karl E.; Shaw, Timothy J.; Wilson, Chris; Yin, Chuan; Zhao, Xixi
Source: Proceedings of the Ocean Drilling Program; scientific results, Iberia abyssal plain; covering Leg 149 of the cruises of the Drilling Vessel JOIDES Resolution; Balboa Harbor, Panama, to Lisbon, Portugal; sites 897-901, 10 March-25 May 1993, Robert B. Whitmarsh, Dale S. Sawyer, Adam Klaus, Marie-Odile Beslier, Eric S. Collins, María Carmen Comas, Guy Cornen, Eric de Kaenel, Luis de Menezes Pinheiro, Elisabeth Gervais, Ian L. Gibson, Dennis L. Harry, Michael A. Hobart, Toshiya Kanamatsu, Charlotte M. Krawcyzk, Li Liu, Jeremy C. Lofts, Kathleen M. Marsaglia, Philip A. Meyers, Doris Milkert, Kitty L. Milliken, Julia K. Morgan, Pedro Ramirez, Karl E. Seifert, Timothy J. Shaw, Chris Wilson, Chuan Yin and Xixi Zhao. Proceedings of the Ocean Drilling Program, Scientific Results, Vol.149, p.571-575. Publisher: Texas A&M University, Ocean Drilling Program, College Station, TX, United States. ISSN: 0884-5891
Note: In English. 40 refs.
Summary: Three serpentinite-breccia units, pre-Late Cretaceous to late Barremian in age, were recovered from Subunit IVA (369.9-484.2 m below seafloor in Hole 899B), one approximately 95 m thick, and two less than 20 m. The three are similar and are interpreted to be bedded tabular units. Each contains angular fragments, many displaying jigsaw/crackle textures, set in a matrix apparently generated by fragmentation of the clasts. Sorting is generally absent, but larger boulders tend to occur in the upper half of the thickest unit. Minor internal deformation zones or slip zones occur. All these features are common in subaerial giant landslide deposits, and the serpentinite breccias are interpreted as being equivalent submarine deposits, generated by slope failure on a nearby large serpentinite fault scarp. Giant landslides are a typical feature of regions undergoing rapid extensional deformation, and such deposits may be relatively common in strongly faulted submarine extensional environments. The basement topography at the time of formation of the serpentinite units probably differed significantly from the present topography buried beneath the Iberia Abyssal Plain. As a result, the location of the source serpentinite escarpment is unknown. However, the large size of some of the fragments included within the serpentinite indicates that it was probably within a few kilometers of Site 899. The aggregate width of the belt of mantle serpentinite exposed in the Late Cretaceous at the Iberia Margin was at least 20 km. Most of this belt is now buried beneath the sediments of the Iberia Abyssal Plain.
Year of Publication: 1996
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Atlantic Ocean; Barremian; Breccia; Continental margin; Cretaceous; Depositional environment; Europe; Extension tectonics; Fractures; Iberian Peninsula; Iberian abyssal plain; Landslides; Leg 149; Lower Cretaceous; Mass movements; Mesozoic; Metaigneous rocks; Metamorphic rocks; Metasomatic rocks; North Atlantic; Northeast Atlantic; ODP Site 899; Ocean Drilling Program; Paleo-oceanography; Serpentinite; Southern Europe; Syntectonic processes; Tectonics
Coordinates: N404622 N404622 W0121604 W0121604
Record ID: 2007088116
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