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Distribution of investigation logs during 1990.
Click on legend button to see the log plots
Detailed studies have been done in the high lighted area.
Click in the red box to see it.
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Shallow vertical sequences across the interfan area demonstrate the dominance of
muddy units over the sandy ones in the surficial sediments. Very few channel
(CH) sequences represented by predominantly sandy horizons are available.
Channel margin sequences (CM) are represented by frequent sand-mud alternations
(levees) or a dominantly sandy horizon in a otherwise muddy matrix (crevasse).
Most frequent are the overbank (OVB) sequences made up of 70-100% mud. A number
of transitional sequences manifest a change of one type of sequence to another
in a relatively short time interval e.g. “channel to overbank” (CH=>OVB) or
“channel to channel margin” (CH=>CM).
The major deposition in the plains is through settling of the suspended
sediments during overbank flooding, almost every year, in most of the rivers.
Further, all these rivers are migratory in nature and pick up large amounts of
fine sediments in suspension through reworking of older deposits and erosion of
muddy banks.
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