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Soil Properties and Geomorphology. Mark Sweeney Earth Sciences – University of South Dakota. ESCI 411: Principles of Geomorphology. Prerequisites: ESCI 101 (Physical Geology) or instructor permission Audience: Earth Science majors, minors, Anthropology majors, Biology graduate students
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Soil Properties and Geomorphology Mark Sweeney Earth Sciences – University of South Dakota
ESCI 411: Principles of Geomorphology • Prerequisites: ESCI 101 (Physical Geology) or instructor permission • Audience: Earth Science majors, minors, Anthropology majors, Biology graduate students • NO LAB • Field trips required
Soil Properties and Geomorphology Source of data: • McFadden, LD, 1978, Soils of the Canada del Oro valley, southern Arizona. M.S. Thesis, U of Arizona, 116 p. • Exercise idea was borrowed from Geomorphology labs taught by: • Eric Straffin (UN-L, 1997) • M. Berry (SIU, 1994)
Goals • Understand relative dating of fluvial terraces • Understand basics of soil formation and properties of soils • horizons • additions • transformations • translocations
Goals • Generate graphs to illustrate changes, if any, in certain soil properties over time • Interpret real soil data • Follow up: On a field trip, apply skills to a soil in loess
Goals • Understand and apply Hans Jenny’s (1941) 5 factors of soil formation (clorpt) • Climate • Organisms • Relief • Parent material • Time Assumed relatively constant for our project Varies
Information Provided Diagram of 5 fluvial terraces Soil properties for each: Soil horizons and thicknesses Soil color Soil texture Soil carbonate % Hints on how to calculate weight mean % (clay, CaCO3) for soils
Exercise • Students calculate soil properties in Excel • Students graph results • Students answer questions: • Which properties vary with age? • Which properties are most discriminating? • Which properties are least discriminating? • Make general statements about how soils form through time in this environment
Results • Time is the factor which controls differences in soils among the fluvial terraces • Supports idea of soil chronosequence • Additional factors must explain changes that are not systematic over time
Results • Difficulty with using Excel and calculating despite hints resulted in errors filtering throughout exercise. • Don’t always see appropriate trends • Otherwise, students seem to grasp basic concepts and gain some appreciation for the 5 soil forming factors