Abstract: Factors Controlling Suspended Sediment in Streams Draining Currently Glaciated Basins

D. A. Link

The effects of 15 factors hypothesized to regulate the supply of suspended sediment to streams draining currently glaciated basins were determined. The concentration, season's tonnage, grain-size distribution, and composition of the suspended load of 7 glacial streams 153 mi (245 km) southeast of Fairbanks, Alaska, were related to the hypothesized controlling factors by multiple-correlation and regression analysis to obtain the relative significance of each factor's effect in the test area.

The suspended loads of the 7 streams were sampled systematically from July to mid-September 1968 and from May to late September 1969. The basic sampling scheme involved sampling each stream at 2 to 4-hour intervals for 24 hours, several times during the 6-month melting season. The melting season accounts for approximately 90 percent of each stream's annual discharge. The sampling scheme thus detected diurnal and seasonal changes in the suspended-sediment load. Water samples were taken in extremely turbulent reaches of each stream and passed through 0.45-µ filters which removed about 99 percent of the material in the water. The samples were returned to the laboratory, dried, weighed to obtain concentration, subjected to settling-tube and pipette analysis (grain-size distribution), and analyzed by X-ray-diffraction methods (composition). These sample parameters then were related to the 15 factors hypothesized to control the contribution of sediments to glacial streams.

AAPG Search and Discovery Article #90972©1976 AAPG-SEPM Annual Convention and Exhibition, New Orleans, LA