Abstract
In midwestern United States the most important widespread environmental event during the Holocene about 8000 y.a. was the establishment of an effective precipitation pattern that in part defines the Prairie Peninsula. The pattern occupies a region that is dominated by dry westerly air for 6–9 mo during normal years and for 9–12 mo during drought years. Regional soil geography correlates readily with zones of precipitation effectiveness with Brunizem (Udolls) conforming to the moist, subhumid zone, Chernozem (Boralls, Udolls) relating to the dry, subhumid zone, and Chestnut and Brown soils (Ustolls) fitting the semiarid zone. During the past few thousand years, a climatic reversal has caused encroachment of forest on prairie resulting in the formation of transitional or intergrade soils. In local areas the Holocene is expressed on the land surface by the soil geomorphic unit which is the repetitive occurrence of a sequence of soils on the erosional surface of a hillslope and on the correlative depositional body at the foot and toe of the slope. This unit embraces time, lithology, landscape, and soils and provides a means for mapping the Holocene on the countryside.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.