skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Morphology and growth pattern of Amazon deep-sea fan: a computer-processed GLORIA side-scan mosaic

Conference · · Am. Assoc. Pet. Geol., Bull.; (United States)
OSTI ID:6571517

Deep-sea fans have become increasingly important targets for exploration because of their favorable facies associations. A better understanding of deep-sea fans is needed to successfully exploit these complex sediment bodies. Recent studies of the Amazon fan, using long-range side-scan sonar (GLORIA) and single-channel seismic data, provide an overall view of channel patterns of this fan and demonstrate the relationship between successive channel/levee systems. The digitally collected GLORIA data have been computer processed to produce a mosaic of the fan. Computer processing has corrected the records for slant range and ship navigation, and targets have been enhanced. Many features of the modern fan system are readily apparent on the sonar mosaic. The 1.5 to 0.5-km (5000 to 1600-ft) wide channels meander intensely across the fan with sinuosities up to 2.5. Because of these meanders, the channel gradients decrease regularly across the fan despite changes in regional slope. Other channel-related targets include cutoff meanders, overbank deposits (especially small debris flows), and channel branchings. Other debris flows cover large areas of the fan and override channel/levee systems. Air-gun records show that this fan is built of a series of channel/levee systems that overlay one another. Channels from at least 6 of these systems are visible at the surface now, but apparently only one channel at a time has been active. The length of time needed to build a single channel/levee system is not known, but it appears to be rapid.

Research Organization:
Lamont-Doherty Geological Observatory, Palisades, NY
OSTI ID:
6571517
Report Number(s):
CONF-8405216-
Journal Information:
Am. Assoc. Pet. Geol., Bull.; (United States), Vol. 68:4; Conference: AAPG annual convention, San Antonio, TX, USA, 20 May 1984
Country of Publication:
United States
Language:
English