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SUMMARY:The Existence and Significance of Deeply Buried Landscapes - Dr Ni
 cholas White\, Department of Earth Sciences\, University of Cambridge
DTSTART:20111110T113000Z
DTEND:20111110T123000Z
UID:TALK33607@talks.cam.ac.uk
CONTACT:Helen Mawdsley
DESCRIPTION:Sedimentary basins in the North Atlantic Ocean preserve a reco
 rd of intermittent uplift during Cenozoic times. These variations in eleva
 tion are thought to result from temperature changes within the underlying 
 Icelandic mantle plume. When parts of the European continental shelf were 
 episodically lifted above sea level\, new landscapes were carved by erosio
 n\, but these landscapes then subsided and were buried beneath marine sedi
 ments. Here\, we use three-dimensional seismic data to reconstruct one of 
 these ancient landscapes that formed off the northwest coast of Europe dur
 ing the Palaeocene–Eocene Thermal Maximum. We identify a drainage networ
 k within the landscape and\, by modelling the profiles of individual river
 s within this network\, we reconstruct the history of surface uplift. We s
 how that the landscape was lifted above sea level in a series of three dis
 crete steps of 200–400m each. After about 1 million years of subaerial e
 xposure\, this landscape was reburied. We use the magnitude and duration o
 f uplift to constrain the temperature and velocity of a mantle-plume anoma
 ly that drove landscape formation. We conclude that pulses of hot\, chemic
 ally depleted\, mantle material spread out radially beneath the lithospher
 ic plate at velocities of 35 cm/yr.\n\n
LOCATION:Open Plan Area\, BP Institute\, Madingley Rise CB3 0EZ
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