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Degree

Doctor of Philosophy, Ohio State University, Soil Science, 2003.

Abstract

This dissertation consists of five journal articles. The first two attempt to answer two critical questions relating to the basic understanding of fracture flow: how quickly do fractures form, how long do they persist? Fractures form very quickly in fill materials from Ohios glacial tills and lakebeds. This discovery raises concern regarding the use of Ohios fine-grained glacial and lacustrine materials in the built environment. The second documents that fractures, once formed, remain indefinitely, unless the materials are eroded away. This discovery is supported by the presence of Green Rust in buried lacustrine materials found in bedrock valleys in Clermont County, Ohio. The Green Rust iron composition is so unstable that when exposed to oxygen, it turns to goethite, yet it has been preserved in its unstable state since the last polar reversal. Water moves in fractures and along bedding planes. Ohio Department of Natural Resources (ODNR), Div. of Water modified their Ground Water Pollution Potential, (DRASTIC) mapping program in 1995. The third paper presents a short history of US EPAs DRASTIC methodology, observations, and philosophical decisions that led ODNR to modify their application of the DRASTIC process. The fourth paper provides an independent evaluation of 21 sites in Ohio where fractures have been identified from boring samples, backhoe pits and stream cuts. The review of these sites confirms 23 of the soils from Tornes and others (2000) and identifies four more. These 27 soils represent almost 8 million acres in Ohio, over 14 million acres in the Midwest. The paper confirms ODNRs modification of DRASTIC mapping, and cautions land-use practices on these soil settings. The fifth paper focuses on an Ohio Fracture Flow Working Group activity, a Field Day held at OSUs Farm Science Review facility, and presents a short history of the use of outdoor sites for educational purposes. Four more field days have been held around Ohio; more are planned.

Keywords

fracture flow; glacial tills and lakebeds; fracture formation; formation time; green rust; DRASTIC; DRASTIC history; DRASTIC modification; fractured till confirmation; fractured soil confirmation; outdoor education; professional education; field day

Advisor

George F. Hall

Pages

xxii, 400 p.: ill (some col.)

Document number: osu1072118096
Permalink: http://rave.ohiolink.edu/etdc/view?acc_num=osu1072118096

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