Channel pattern and sedimentation styles in an alluvial plain distributor fluvial system [of Castlereagh river, New South Wales, Australia]
1990
Alam, M.M. (Dhaka Univ. (Bangladesh). Dept. of Geology)
The Castlereagh river, with highly variable discharges, changes its channel pattern downstream. The upstream 100 km reach is lowsinuosity braided bed-load; middle 20 km is anastomosing bed-load to mixed-load interconnected channels; and downstream 40 km is highsinuosity mixed-to suspended-load distributive. Deposition by the present regime develops the following sedimentation styles: in braided environment facies profile comprises; trough cross-bedded sand tabular cross-bedded sand ripple-laminated sand inter-bedded sand and mud overbank mud. (2) Profile in anastomosed environment comprises; trough cross-bedded sand interbeds of trough and tabular cross-bedded sand laminated silt/clay, (3) In distributive environment profile comprises: trough and tabular cross-bedded sand ripple- laminated sand poorly laminated sand/mud. The system essentially represents an inland distributive fluvial pattern. It produces ribbon-like channel sand bodies which become thinner, finer- grained and numerous downstream through a large volume of overbank mud with minor intercalated organic concentration.
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