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f Giant Mass Transport Complex from the Distal Magdalena Fan, Offshore Colombia : Seismic Characterization
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 11th Simposio Bolivariano - Exploracion Petrolera en las Cuencas Subandinas, Jul 2012, cp-330-00093
Abstract
A giant (>3000 km3) mass transport complex (MTC) is imaged from the distal Magdalena Fan, offshore Colombia. The MTC is imaged on a loose grid of 2D seismic data, located in ultra-deep water 150-200 km north of the city of Barranquilla. The deposit varies in thickness from ~40-200 m, thinning onto pre-existing seafloor topography. The area of the slide is >25,000 km2. Calculations indicate a volume larger than 3000 cubic kilometers of sediment was involved in this single catastrophic event. The MTC is likely Pleistocene in age as constrained by the DSDP site 153 well penetration. The top of the deposit is defined by a relatively rugose seismic reflector and lies only 150 m below the present day seafloor. Internally, a variety of seismic facies are present, ranging from incoherent/chaotic within the core of the deposit, to continuous reflections broken by small scale, regular reverse faults at the margins. Little to no erosion appears to have occurred at the base of the deposit, as evidenced by continuous and conformable reflections in the interface between the underlying sediments and the base of the MTC.