Robert (Bob) Diffendal

Robert (Bob) Diffendal

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Title Emeritus Research Geologist
Address 605 Hardin Hall
3310 Holdrege Street
Lincoln NE
Phone 402-472-7546 & 402-472-5618
FAX 402-472-2946
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Bob Diffendal is a geologist and professor emeritus in the School of Natural Resources.

While he formally retired in September of 2003, he remains quite active in the School and University, particularly in writing and public speaking about Earth science.

He sees many benefits to a career in geology: "This discipline gets you outside, looking at a major component of natural resources," he said. "If you stop and consider, almost everything in this building is constructed out of stuff that people dug out of the ground and transformed. In terms of our civilization, it's extremely important that people are trained to go out and find resources that all of us can use in our daily lives."

He added that it's also essential for practicing geologists to have a general understanding of other natural sciences, as well as a background in humanities and social science. They need to be able to write, to speak to groups of people and to understand what goes on in government agencies.

How it all began

Bob's interest in geology started early in life. When he was 10 years old, growing up in Hagerstown, MD, Bob and his friends used to pass the Porter Chemical Company, a maker of children's science sets, on their way to school. After school, they scavenged in the dump behind the factory for items discarded by the plant manager. One day Bob found a pile of mineral specimens and took them home. He bought a book on mineral identification and from then on he knew he wanted to be a geologist.

After high school, Bob attended Franklin and Marshall College in Lancaster, PA. It was around then that a stroke of what Bob calls "luck" a life-changing casual encounter occurred. As a senior in college, walking through a field to show the chair of his department the site that he had mapped for his thesis project, the chair asked Bob about his plans after graduation. Bob said he planned to get a certificate and become a high school teacher. The professor said, "No, you don't want to do that. You want to go to graduate school." Bob wonders how his life would have turned out if that conversation hadn't happened.

Bob had read an article on paleontology by Al Fagerstrom at Nebraska, so he applied here. He received his M.S. degree at the University of Nebraska-Lincoln in 1964 and started work on his Ph.D. In 1966, he had a chance to teach geology at a college in Illinois, and took the job while continuing to work on his doctorate. Whilte there, he met his wife Anne and they married in 1967.

The college in Illinois closed in 1970, and Bob took a job at Doane College in Crete, NE, completing his Ph.D. in December 1971. Bob was awarded tenure at Doane in 1974 and was science division chair and associate academic dean there in the late 1970s.

In 1975, Bob asked Ray Burchett if there was any summer work at the Conservation Survey Division (CSD), which is now part of the School of Natural Resources. Ray said he needed someone to prepare geologic maps. Bob assumed the mapping would be in southeast Nebraska where he had studied the stratigraphy and paleontology for his M.S. thesis work, but he didn't ask. After he accepted the job, Ray asked him to begin mapping in the Ogallala area, which was "not a spot I would have picked on my own," Bob said. "It's a whole different geology than the areas in southeast Nebraska that I was familiar with. I started out trained in invertebrate paleontology - animals without backbones. I went out and made maps of major parts of Nebraska that had nothing to do with little critters."

Bob kept working summers for CSD from 1975 to 1979, took a "soft money" job here from 1980 to 1981 while on leave from Doane, and then moved into a permanent CSD faculty position, earning tenure in 1986. Since coming to UNL, Bob has authored or co-authored more than 300 publications and other works.

During his active career, Bob's major research emphases were on geologic mapping of various parts of Nebraska, as well as other geological research resulting in publication of maps, articles and public educational materials. He has continued these emphases since retirement. He also continues to give talks on the geology of Nebraska and elsewhere, and to lead field trips to sites in Nebraska for people of all ages.

His specific research interests have to do with the geology of western and north-central Nebraska; Upper Paleozoic, Mesozoic and Cenozoic geology, mostly in Nebraska, and invertebrate fossils.

He has also done research on the geology of parts of China. He has had a long-standing interest in the culture, people and landscape of China and has made ten trips there over the last 35 years to teach, tour, and do research. One of the products of Bob's interest in China was the Diffendal Foundation, endowing a scholarship fund for geosciences students at Sun Yat-Sen University in Guangzhou, China.

In addition to his scholarly work, Bob willingly assumed many key administrative roles over the years. He served as:

  • SNR coordinator on Hardin Hall, including coordinating input into and keeping people informed of progress on the School's new building
  • Executive secretary of the North-Central Section of the Geological Society of America (GSA)
  • Associate editor and editorial board member of the Journal of Geosciences of China
  • a member of the GSA Annual Program Committee
  • Chair and organizer of the 1995 combined North-Central/South-Central Regional Meeting of GSA
  • President of the UNL Faculty Senate in 1988-89
  • Interim associate director of the Conservation Survey Division, 1990-91
  • First assistant director of the School of Natural Resources

Current work

In 2008, he completed a significant publishing - as first author with five other researchers - of a geologic map and accompanying text for a major part of north-central Nebraska. The "Geologic Map of the O'Neill 1° x 2° Quadrangle, Nebraska, with Configuration Maps of Surfaces of Formations" was published at a scale of 1:250,000 by the UNL School of Natural Resources' Conservation and Survey Division as GMC-34. His co-authors on this project were Michael Voorhies (Emeritus UNL), Jane Voorhies, H.E. LaGarry (Oglala Lakota College), C.L. Timperley (University of Texas at Austin), and M.E. Perkins (University of Utah). Additional information with the maps and text includes descriptions of all major geologic formations exposed in the map area and locations of landslides, possible earthquake faults, some quarries and pits, and volcanic ash sites. The geologic development of the area is described in some detail. Most works on the area published through 2008 on geology, soils, paleontology, groundwater and other natural resources, and geologic hazards are cited in the text and noted in the references section of the pamphlet.

Information on GMC-34 is available through the School of Natural Resources at: (402) 472-3471 or by email at

Other current professional service activities include:

  • Curator of the Invertebrate Paleontology collections of the University of Nebraska State Museum
  • A member of the UNL Chancellor's Speaker's Bureau

Selected Publications

Diffendal, Robert. 2014. Geologic Observations along the Steamboat Trace Trail, Markers 16-20, in the vicinity of Peru, Nemaha County, Nebraska (including on the Indian Cave Sandstone): University of Nebraska Digital Commons   On-Line
Perkins, M.E., Diffendal, R.F., Jr., Voorhies, M.R., Nash, B.P., and Bailey, B.E.; Ashfall Tephra in the Ogallala Group of the Great Plains: Characteristics and Significance: Geological Society of America Abstracts With Programs, v. 46 (4): p. 51.
Foreword: In Jorus, J. et al, The Groundwater Atlas of Nebraska (3rd Revised Edition), Conservation and Survey Division, University of Nebraska, Resource Atlas 4b, p. vii.
Wooden, S.R., Joeckel, R.M., Korus, J.T.,and Diffendal, R.F., Jr.; Lithofacies and Stratigraphic Architecture of the Ash Hollow Formation, Ogallala Group in the General Type Area: Geological Society of America Abstracts With Programs, v. 43 (5), p. 601.
Joeckel, R.M., R.F. Diffendal, Jr., 2004. Geomorphic and Environmental Change Around a Large, Aging Reservoir: Lake C.W. McConaughy, Western Nebraska, USA. Environmental and Engineering Geology, 10: 69-90.
Pabian, R.K. and R.F. Diffendal, Jr. 2003. Late Pennsylvanian and Earliest Permian Cyclic Sedimentation and Paleoecology in Southeastern Nebraska. Missouri Geological Survey Special Publication. 11:35-52.
Diffendal, R.F., Jr.. 1999. Earth in Four Dimensions - Development of the Ideas of Geologic Time and History. Nebraska History. 80:95-104.
Huang, P-H, R.F. Diffendal, Jr. and M. Yang. 2002. Structural and Geomorphic Evolution of Hangshan (Yellow Mountain), Anhui Province, China. TER-QUA Symposium Series. 3:109-124.
Huang, P-H. and R.F. Diffendal, Jr.. 1998. Mountain Evolution and Environmental Changes of Huangshan, China. Scientia Geographic Sinica. 18:401-408.


  • 2014 – John C. Frye Memorial Award awarded by Association of American State Geologists 

SNR Mission Area(s)

  • Environmental Science

Affiliations (index)

Notable Websites

Other Areas of Interest

Emeritus; Nebraska Geologic Mapping, Stratigraphy, Sedimentology, Geomorphology, Paleogeography and Paleontology; Geology of western/north-central Nebr.; Upper Paleozoic, Mesozoic and Cenozoic geology; invertebrate fossils; field guides; geology of parts of China

SNR Areas of Expertise

Keyword Expert Level

10 - Top Expert
1 - Mild Interest





Great Plains




Rocks and Stones




Natural Resources






Physical Geography


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Currently this page only displays grants that were awarded on 1/1/2009 to the present. If a grant was awarded prior to 1/1/2009 and is still active, it will not be displayed on this page.

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SNR Speakers Bureau

What I can speak about:

Slide Talks

Lewis and Clark and the Geology of the Great Plains/Nebraska and Adjacent States; Geologic Development of the Ogallala/High Plains Regional Aquifer Across The Great Plains; Floods, Fires, Earthquakes, Landslides and Other Natural Hazards in Nebraska and Elsewhere; Fossils from Nebraska's Ancient Seas

Hands-on Activities

Mineral and Rock Identification; Fossil Identification; Topographic and Geologic Map Reading; What is Sand?; Techniques for Collecting and Identifying Microscopic Fossils from Sediments and Sedimentary Rocks

When I am most available to speak:


What target audiences I am most comfortable speaking to:

  • College
  • OLLI - lifelong learning for adults 50 years and older)
  • General Public
  • Families