In 1947, H. Garland Hershey succeeded Trowbridge, with whom he had served as assistant state geologist beginning in 1939. This was also the watershed year in which the director of the Geological Survey and the chair of the Department of Geology were separated into two full-time positions. Today the Geological Survey and the Department of Geology continue to enjoy a beneficial association, sharing a good library and lab facilities, with the survey providing opportunities for student employment, staff guidance on Iowa-based thesis projects, and occasionally filling the role of adjunct professor.
In his 22 years of service, Hershey greatly expanded the survey’s groundwater research and service functions. The post-war expansion of Iowa’s economy included industry as well as agriculture. Hershey observed, “One of the first needs of new industry locating in Iowa is a good water supply, usually obtained from wells they drill with the aid of information from our records,”(Jensen, 1955). Those records now include more than 30,000 wells, including sample sets of drill cuttings, drillers’ logs, and rock cores. The collection and interpretation of these records is the heart of the survey database. They reflect a continuing cooperative association with the state’s water-well drillers and are invaluable in the preparation of groundwater availability forecasts and in addressing water resource issues. This improved database also made possible the siting of underground natural gas and liquid-petroleum-gas storage facilities in Iowa.
Samuel J. Tuthill’s career as state geologist and director began in 1969 and is notable for the creative application of the survey’s traditional research and service functions to the resource, environmental, and energy issues that faced Iowa in the early 1970s. A scientific investigation of Cold Water Cave was conducted to determine its potential as a scientific and public resource. New regulations governing site selection of sanitary landfills were adopted based on geologic criteria designed to protect water resources. The Remote Sensing Laboratory was established within the Survey to apply information from aerial and satellite imagery to a broad range of interagency users. The first land-use map of the state was produced and new methods of flood-hazard assessment were inaugurated using this information base. The expansion and diversification of public services and interagency cooperation included his teaming with other agency administrators and the Governor’s Office to coordinate Iowa’s response to the 1973 Arab oil embargo. A coal-resources evaluation program and a drilling program to examine the hydrology of carbonate aquifers in the eastern Iowa groundwater district were also established. He focused public attention on the role of carbonate rocks and the impact of agriculture on groundwater problems. In a 1972 speech delivered to a seminar for community leaders he stated, “It is not the use of chemicals that serve agriculture, it is the chemicals that escape productive agricultural systems that damage water resources.” This emphasis on the importance of understanding geologic systems in addressing the state’s environmental concerns continues today as a concept fundamental to our existence.
Stanley C. Grant took over the reins of the Iowa Geological Survey in 1975. As the staff had grown from about 14 in 1965 to 41 in 1978, he initiated an internal reorganization into several management divisions reflecting the Survey’s various programs and functions. An annual Newsletter joined the list of Survey publications in 1976 and in 1979 became known as Iowa Geology, a magazine of illustrated articles designed to communicate important and interesting information about the state’s geology to the public. The Survey’s advisory role to other state and federal agencies continued to expand in the areas of remote sensing applications, energy resources, data systems management, and “environmental geology,” a term that came in vogue to describe this more intense and visible, practical application of geology to contemporary resources issues. Highlights of programs that continued or were initiated during this period included development of a state water plan, study of strippable coal reserves, availability of groundwater for irrigation, applied soils engineering and surficial geology studies, monitoring of earthquake activity, appraisal of groundwater occurrence and quality by aquifer and region, uses of Mississippi River dredge materials, geologic analysis of the Cherokee Archaeological Site, Missouri River landownership litigations, toxic waste problems, Plum River Fault zone mapping, Pleistocene stratigraphy, and improvements in data storage and retrieval systems.
Donald L. Koch became Director and State Geologist in 1980, noting the Survey’s improved capabilities in problem-solving and service functions as a result of refinements in data collection and interpretation over the years. Growing interest in the Midcontinent Rift Zone, a good example of refinements in geophysical techniques, resulted in the 1987 completion of the deepest well yet drilled in Iowa, the M.G. Eischeid No. 1 in Carroll County, an AMOCO Production Company oil and gas test to 17,851 feet. Also, 1987 was a milestone in terms of the completion of state-wide topographic map coverage by the USGS 7.5-minute quadrangle series. An abundant concentration of Mississippian amphibian fossils, perhaps the oldest known tetrapods in North America, was discovered in Keokuk County in 1985. Major studies also continue in water resources evaluation, especially the documentation of water-quality degradation in shallow carbonate and alluvial aquifers. Research efforts are oriented toward development of land treatment and management strategies that can be implemented to reduce groundwater contamination. Other studies include agricultural drainage wells, leakage from underground storage tanks, abandoned coal-mine lands and subsidence problems, geomorphological influences on the preservation of archaeological resources, Des Moines Lobe surficial geology, a municipal water-supply inventory, Plum River Fault Zone mineralization, and enhanced computer processing capabilities.