Rob L. Evans, L.K. Law, B. St. Louis and S. Cheesman, Buried paleo-channels on the New Jersey continental margin:
channel porosity structures from electromagnetic surveying, Marine Geol., vol 170, 2000
We report on a marine electromagnetic (EM) survey across two portions of the New Jersey continental margin that have been
previously shown to contain buried paleo-channels. The EM method used provides bulk porosity estimates to depths of around
20 m below the sea?oor and is thus able to place porosity constraints on the nature of the channel in?ll and the contrast in
physical properties across the channel boundaries. Our data show that a key condition for the channels to have an electrical
signature is that they incise an underlying regional unconformity, R, thought to represent a subaerially eroded surface, exposed
during the late Wisconsinan glaciation. Channels that cut R are seen through increases in apparent porosity. Another seismically
imaged channel sequence, which lies within the outer-shelf sediment wedge sequence above R, does not have an electrical
signature, indicating that the sediments above and below the channel boundaries have similar physical properties.
FILE » margeol_2000_7970.pdf
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