Observations on Opal Phytoliths in a Soil Biosequence in Southeastern Minnesota
1969
Verma, Shive D. | Rust, R. H.
The content of opal phytoliths was measured in selected horizons of six soils from Goodhue County, Minn. The highest amount of opal phytoliths occurred in a Typic Hapludoll (Kenyon series) suggesting a soil developed under dominant grass vegetation because most of the opal is derived from big bluestem (Andropogon gerardi L.) and little bluestem (A. scoparius L.). Opal phytoliths isolated from some horizons were similar in morphology to reference slides made of opal from burr oak (Quercus macrocarpa Michx.), ironwood (Ostrya virginiana (Mill.) K. Koch), and a shrub, hazel (Corylus americana Walt.). Opal phytoliths in two associated Aquollic Hapludalfs (Kasson and Taopi series) were derived primarily from big and little bluestem and with minor amounts from trees. This suggested at least a period of forest vegetation. A striking feature of Kasson, Kenyon, and Taopi soils is the higher content of opal phytoliths in till material II which begins in the B² horizon at depths of about 50 inches. Possibly at one time the top of material II might have been prairie covered landscape and the overlying silty material was deposited later.
显示更多 [+] 显示较少 [-]