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Drainage Interpretation
Discussion / Conclusions
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Discussion
Inland Delta
There has been comparisons of the Blood Creek and Deception Creek's drainage to
that of a "Mississippi Bird's Foot" Deltaic Complex. However it is a simple
geomorphic principle that deals with the change in velocity of the stream. The
creek upon entering the flat basin deposits its detrital load as a delta. As the
stream continues into the basin, the creek extends its length and branches into
several channels called distributaries that are flanked by natural levees. Over
time, one or more distributaries caries more discharge than adjoining ones, and
the delta growth is shifted to other distributaries so that the enter deltaic
area expands into the basin.
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The delta complex of Blood Creek as it enters Cheyenne Bottoms. There are
several abandoned channels that show previous paths of Blood Creek. The current
channel shows evidence of natural levees.
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Delta of the Omo River as it dumps into Lake Turkana, Kenya. A new lobe of
the delta is forming at the current river's entry into the lake. NASA Photograph
NM22-746-081
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The Niger River Delta is the largest inland delta in the world. This delta
exhibits similar characteristics to the bird-foot delta of the Mississippi
River. NASA Photograph NM23-730-271.
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A simple reconstruction of the Mississippi Delta showing the probable course of
the Mississippi River. 1 - an older delta lobe, 2 - the previous delta lobe, 3 -
the current delta; a - Mississippi River, b - older channel leading to delta
'1', c - source of cut-off to delta '2', d - natural levees forming along
channel to current delta. Base map obtained from NOAA, processed by S. W. Salley
©, 11/04. |
Geology
The question about how Cheyenne Bottoms formed still will allude geologists for
many years. Perhaps until 3d-seismic data is obtained to verify or rule out
structural movement or salt dissolution all theories should be considered for
the formation of the basin. One theory that is overlooked in most literature is
the stream capture of the Upper Smoky Hills River. This theory should be
considered in the genesis of the bottoms in part.
Conclusion
Based on the field observations and aerial analysis of Cheyenne Bottoms, the
following conclusions can be assumed: (1) Surface drainage does have similar
characteristics to inland delta patterns. (2) Aerial photography can aid
reconstructions of abandoned channels through differential vegetation. (3)
Management practices have changed the Bottoms drainage patterns. (4)
Pre-management drainage of the Bottoms exhibited a general surface sheet flow to
the south-east. (5) The origin of the basin is complex geologically and no
single theory can answer to its genesis.
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