Effect of influx of Eolian materials on soil formation

摘要

The quantity of quartz and its size distribution was determined in soils formed from quartz free basaltic tephra on Greens Peak, Apache County, Arizona. The soils showed a decrease in quartz content from the east side to the west side of the peak. The percentage of averaged weighed quartz content in the upper soil horizons ranged from (36.1%-13.9%) on the east side and (19.9%-12.3%) on the west side. The content of quartz was higher in the surface soil horizons than in the lower horizons. Large amounts of quartz occurred in the sand and silt fraction, whereas no quartz was detected in the clay fractions. Quartz is concentrated mostly in the coarse silt (22-53 μm) fraction (50%). Quartz particle size distribution in these soils is dominantly in the range of 17-53 μm particle count based, and (17-63 μm) mass based. The abundance of silt and very fine sand quartz, and the paucity of aerosolic quartz 1-10 μm in these fractions is indicative of dust transported short distances from the local sources. It is suggested that the quartz was added as loess sized material of mainly local origin brought into the profiles by eolian transport.