TY - JOUR
T1 - Millennial-scale sea-level control on avulsion events on the Amazon Fan
AU - Maslin, Mark
AU - Knutz, Paul C.
AU - Ramsay, Tony
N1 - Funding Information:
We would like to acknowledge the comments, suggestions and technical help of the following: R. Flood, D. Piper, E. Platzman, P. Grootes, N. Mikkelsen, P. Manley, S.E.J. Greig, M-J. Nadeau, M. Schleicher, B. Lomax and N. Rimington, A. Cramp, Ship crew and scientific party of ODP Leg 155. This study was funded by NERC NER/B/S/2001/00380, IP/660/0900 and GR9/3526. We would like to thank the reviews John Andrews and Beth Christensen for the helpful comments and insights. We dedicate this paper to the memory of Nick Shackleton, supervisor, mentor and friend.
PY - 2006/12
Y1 - 2006/12
N2 - The Late Quaternary Amazon deep-sea fan provides a modern analogue to ancient fan systems containing coarse-grained hydrocarbon reservoirs. Sand lenses deposited within the Amazon Fan, due to abrupt shifts in channel pathways called avulsion events, were drilled as part of ODP Leg 155. The hemipelagic sediment directly on top of the avulsion sands was dated using primarily AMS radio carbon dating. This dating shows that these large sand lobes (∼1 km3) are triggered by relatively small, millennial scale changes in marine transgression and regression (±5-10 m). Relative sea level also controls the architecture of the Channel-levee distributive systems within the Amazon Fan. For example prior to 22 k calendar years BP there is a tripartite channel system. After 22 ka there is only one active Channel-levee system. Transitions between the multi-channel and single channel configurations are related to variations in the volume of sediment supply resulting in aggradation or erosion of channel floor and levee growth in the canyon-channel transition area. The sensitivity of the Amazon deep-sea Fan sedimentation to relatively small changes in sea level supports one of the central assumptions of the theory of Sequence Stratigraphy. In addition this study demonstrates how traps for hydrocarbons may have been formed in ancient fan systems.
AB - The Late Quaternary Amazon deep-sea fan provides a modern analogue to ancient fan systems containing coarse-grained hydrocarbon reservoirs. Sand lenses deposited within the Amazon Fan, due to abrupt shifts in channel pathways called avulsion events, were drilled as part of ODP Leg 155. The hemipelagic sediment directly on top of the avulsion sands was dated using primarily AMS radio carbon dating. This dating shows that these large sand lobes (∼1 km3) are triggered by relatively small, millennial scale changes in marine transgression and regression (±5-10 m). Relative sea level also controls the architecture of the Channel-levee distributive systems within the Amazon Fan. For example prior to 22 k calendar years BP there is a tripartite channel system. After 22 ka there is only one active Channel-levee system. Transitions between the multi-channel and single channel configurations are related to variations in the volume of sediment supply resulting in aggradation or erosion of channel floor and levee growth in the canyon-channel transition area. The sensitivity of the Amazon deep-sea Fan sedimentation to relatively small changes in sea level supports one of the central assumptions of the theory of Sequence Stratigraphy. In addition this study demonstrates how traps for hydrocarbons may have been formed in ancient fan systems.
UR - http://www.scopus.com/inward/record.url?scp=33846847725&partnerID=8YFLogxK
U2 - 10.1016/j.quascirev.2006.10.012
DO - 10.1016/j.quascirev.2006.10.012
M3 - Article
AN - SCOPUS:33846847725
SN - 0277-3791
VL - 25
SP - 3338
EP - 3345
JO - Quaternary Science Reviews
JF - Quaternary Science Reviews
IS - 23-24
ER -