About This Item
Share This Item
Abstract
Journal of Sedimentary Research, Section
A: Sedimentary Petrology and Processes
Vol. 66 (1996)No.
5. (September), Pages 916-927
Sediment Mass-Flow Processes on a Depositional Lobe, Outer Mississippi
Fan
William C. Schwab (1), Homa J. Lee (2), David C. Twichell
(1), Jacques Locat (3), C. Hans Nelson (2), William G. McArthur (2), Neil
H. Kenyon (4)
ABSTRACT
SeaMARC 1A sidescan-sonar imagery and cores from the distal reaches
of a depositional lobe on the Mississippi Fan show that channelized mass
flow was the dominant mechanism for transport of silt and sand during the
formation of this part of the fan. Sediments in these flows were rapidly
deposited once outside of their confining channels. The depositional lobe
is formed of a series of long, narrow sublobes composed of thin-bedded
turbidites (normally graded siliciclastic sand and silt, 20 cm thick on
average), debris-flow deposits (soft clay clasts up to 5 cm in diameter
in a siliciclastic silt matrix, 48 cm thick on average), and background-sedimentation
hemipelagic muds. The mass flows most likely originated from slope failure
at the head of the Mississippi Canyon or on the outer ontinental shelf
and flowed approximately 500 km to the distal reaches of the fan, with
debris flow being the dominant flow type. An analysis that uses the geometry
of the confining channels and strength properties of the debris-flow material
shows that these thin debris flows could have traveled hundreds of kilometers
on extremely small sea-floor slopes at low velocities if the flowing medium
behaved as Bingham fluids and were steady-state phenomena.
Pay-Per-View Purchase Options
The article is available through a document delivery service. Explain these Purchase Options.
| Watermarked PDF Document: $14 |
Watermarked Document – A Watermarked Document is branded with the name of the original licensed customer to discourage unauthorized users from sharing the document outside the user's organization. The PDF is no longer restricted to one machine, but can be circulated to others in the same company or department. A Watermarked Document also can be printed for hard copy distribution internally but is not authorized for outside distribution nor posting on the internet. Users will not be able to cut-and-paste text or images from one document to another.
|
| Open PDF Document: $24 |
Open Document – An Open Document is a fully functional PDF that can be circulated (a digital copy or hard-copy printed documents) outside the purchasing organization. Purchase of an Open Document does NOT constitute license for republication in any form, nor does it allow web posting without prior written permission from AAPG/Datapages ([email protected]).
|
GIS Map Publishing Program
