Photolinears, Fractures, and Fallacies: What Can We Assume About the Structures of ASR Host Strata?

Monday, December 4, 2017: 2:30 p.m.
Michael Alfieri, P.G., P.Hg., CGWP , Water Resource Associates, LLC, Tampa, FL
Sam Upchurch, Ph.D., P.G. , SDII Global Corporation, Tampa, FL

There is a general misconception by some in the geologic, and non-geologic communities, that terms “photolineaments” (or “photolinear”) and fractures are synonymous. This fallacy can be very detrimental to scientific/geologic interpretations. For example, a potable well placed at the intersection of two photolineaments may not be productive and would be a costly error if is not ground-truthed, because aerial interpretation of soil tones, for example, can be easily confused with intersecting deer trails. A photolineament assessment is a screening tool which requires verification prior to any further geologic interpretations or opinions. While in other areas of the country there is a higher correlation between photolinears and fractures/fracture systems, due to the cover materials, thicknesses, and karst in Florida, this degree of correlation does not exist. In the State of Florida, there have been four major regional photolinear assessments. To date, the authors are unaware of any literature references documenting the verification of these aerial interpreted features. This has led to the misuse of these assessments in geologic interpretations. The case study discussed herein describes the verification of a photolinear assessment completed in Hillsborough County, Florida and demonstrates how the misuse of photolinear assessments can impact geologic interpretation.

Keywords: “ground-truthed”, “ground-truthing”, photolineament, photolinear, fractures, fissures, joints, faults, fracture trace, geology, stratigraphy, karst, sinkholes, conduits, ground penetrating radar (GPR), seismic refraction, seismic reflection, standard penetration test (SPT) borings, cone penetrometer test (CPT) soundings, and Hillsborough County, Florida

Michael Alfieri, P.G., P.Hg., CGWP, Water Resource Associates, LLC, Tampa, FL
A professionally licensed geologist in thirteen states and a nationally certified/registered hydrogeologist, Mr. Alfieri currently manages the operation of hydrogeologic services for Water Resource Associates, LLC (WRA). As a Principal Hydrogeologist at WRA, he provides: geologic, hydrogeologic, and karst science interpretation and evaluations; consumptive/water use permitting assistance; alternative water supply solutions; groundwater flow modeling; and expert witness services. Mr. Alfieri has extensive experience and knowledge in the area of hydrogeology and evaluating hydrogeologic systems. He conducted and/or managed the design of many hydrogeologic investigations and the collection of field data for water resource evaluations across the United States, as well as performed third party reviews of hydrogeologic evaluations. Mr. Alfieri is the Chair of the Florida Board of Professional Geologists and the Chairman of ASTM Sub-Committee D18.21.03: Well Design, Maintenance & Construction.



Sam Upchurch, Ph.D., P.G., SDII Global Corporation, Tampa, FL
Dr. Sam B. Upchurch, P.G. has spent 50 years teaching and conducting research in karst geomorphology and geochemistry, for which he is internationally known. He is also an expert in the application of statistics to geological problems, design of sampling plans, and engineering geology. He is the author of over 200 articles and chapters in books, and has edited several published collections of papers. He is a Senior Fellow of the Geological Society of America (GSA) and has received numerous awards for his research and service to the geological community. He is a former Professor and Chairman of the Geology Department at the University of South Florida (USF) and, more recently, has served as a partner and principal in two international consulting firms (Environmental Resources Management and SDII Global Corporation [SDII]). Prior to joining the faculty at USF he taught at Michigan State University and served as a Research Physical Scientist for the U.S. Army Corps of Engineers (Captain, Retired) Great Lakes Research Center in Detroit, MI. He was appointed to serve on Florida’s first Board of Professional Geologists and is licensed to practice in Florida and Tennessee.


NGWA Groundwater Summit is being held in conjunction with Groundwater Week.

Find out more about NGWA and our events.

National Ground Water Association
601 Dempsey Road
Westerville, Ohio 43081
USA
Phone 614 898.7791
(toll-free within the United States 800 551.7379)
Fax 614 898.7786
Email ngwa@ngwa.org

Websites:

http://www.ngwa.org/ —home site of NGWA

http://www.wellowner.org — information for well owners