'A Pile' — Not Layers — of Leaves
A Look Back
Perhaps
a review — and awareness — of the past may make us better geologists
in the future.
"Sedimentation
Framework of the Modern Mississippi Delta," by Fisk, McFarlan and
Kolb, Journal of Sedimentary Petrology, June 1954.
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Perhaps
a review — and awareness — of the past may make us better geologists
in the future.
"Sedimentation
Framework of the Modern Mississippi Delta," by Fisk, McFarlan and
Kolb, Journal of Sedimentary Petrology, June 1954.
The prior
concept of a systematic arrangement of top set, foreset and bottom
set beds is shown to be invalid for large scale features such as
the Mississippi Delta.
" … Sediments
of the river mouth region are arranged in leaf-like form, with the
deposits of the natural levees and associated channels forming the
veins and veinlets, and those of the marshes representing the inter-vein
portions of the leaf. Subsidence and shifting of the river channels,
combined with long-continued deposition, have created a 'pile of
leaves' structure beneath the extensive deltaic plain of the Mississippi."
This was
an important and early paper that demonstrated the complex and variable
sediment patterns in a "bird foot" delta — a delta where sediment
inflow is overpowering wave action on a shallow shelf.
Rufus LeBlanc,
Sidney Powers medalist, spent 40 more years at Shell's Bellaire
Research, powerfully expanding and amplifying this pioneering work
by Fisk, et al.