Common Ground Between Applied Geology and Engineering
Horacio Ferriz, Physics and Geology, California State University-Stanislaus
Engineering, the most creative profession in the world! In Latin and its derived languages, the word engineering (e.g., ingeniería in Spanish) is derived from the word ingenuity (e.g., ingenio in Spanish). The scope of Engineering is the solution of problems through ingenuity, often with the help of technology and scientific knowledge. Since problem solving is as old as humanity itself, engineering is as fundamental a human activity as art or language. It is surprising that many universities do not have engineering programs as part of their "liberal arts" curricula!
Geology is the scientific study of the Earth, including the solid Earth, the hydrosphere, and the atmosphere. Some of this study is "academic", as practiced in research institutions, but a lot of it is applied in the sense that it is used for the solution of problems relevant to society. In this regard, then, applied geology and engineering have a common goal. Enter, then the practice of geological engineering, which could be divided in:- Engineering geology, whose practitioners provide civil engineers with the information on soil strength, rock mechanics, or seismic behavior that is needed to design lasting civil works. Engineering geologists are also involved in the location of suitable banks of construction materials, mapping of active fault strands, and estimation of compaction potential, slope stability, and liquefaction susceptibility.
- Ore deposits geology (aka economic geology), whose practitioners explore and locate the mineral deposits that will be extracted by the mining engineer, and will be refined by the metallurgical engineer.
- Petroleum geology, whose practitioners explore and locate petroleum and natural gas that will be extracted by the petroleum engineer.
- Hydrogeology, whose practitioners characterize the variability and availability of surface water that will be managed by the hydraulic engineer, locate and characterize groundwater resources, and help design dewatering approaches needed by civil and mining engineers.
- Environmental geology, whose practitioners locate and quantify contamination in soil and groundwater, and in concert with environmental engineers design strategies for cleanup. It is quite common for environmental geologists to be well versed in hydrogeology and applied geochemistry.
- Applied geophysics, whose practitioners survey the Earth by physical methods with the intent to measure properties needed for civil engineering design or to contribute in the location of construction materials, mineral deposits, petroleum reservoirs, aquifers, or contaminated groundwater.
- Applied geochemistry, whose practitioners contribute in the location of mineral deposits and petroleum reservoirs, or in the destruction of soil and groundwater contaminants.
Perhaps the most effective ways I have found to trigger interest in applied geology/geological engineering has been through laboratory or field exercises that give the students a flavor for what may be expected of them in professional life. By the course in which the exercises are presented:
Applied Geology (a course that covers engineering geology and ore deposits geology)
- Topographic survey of a slope, and calculation of its factor of safety under static and dynamic conditions. I need to add a construction design to this exercise, so the students can see what changes could be induced if say a water tank were placed on the slope. It would also be nice to add sample collection and measurement of strength parameters in the laboratory.
- Geologic mapping of a coastal location, and assessment of erosion potential. We did this project once and it was very successful, but I have not had the chance to go back and repeat it. Also, the follow up was weak, and I ended having to write the final report myself.
- Geologic reconnaissance of the Yerington porphyry copper deposit in Nevada. This project triggered a lot of interest in ore deposits geology among my students, but we needed more time for them to look at core and do some mapping. Mapping is difficult in these heavily hydrothermal altered rocks, so I need to find a prospect with less alteration. The students would like to have a couple of labs in core logging, so I need to get some core donated.
Hydrogeology
- Hydrogeologic survey of a small valley. A County Park in a narrow canyon found contamination in their water supply, and asked for recommendations. The students mapped the alluvium-to-bedrock boundary, surveyed the elevations of all water bodies and wells with a standard topographic level, and collected basic geochemical data (pH, electric conductivity) to determine paths of groundwater flow.
- Groundwater table mapping and sample contamination at an abandoned gasoline station. The students used a standard topographic level and a groundwater depth sounder to determine the geometry of the water table based on ten groundwater monitoring wells. They also learned how to collect groundwater samples for contamination studies. This site is actually only marginally contaminated, but I need to develop an imaginary scenario, where a gasoline plume from the site intermingles with a PCE regional plume.
Geophysical Exploration (a course that also covers the foundations of petroleum geology)
- Resistivity survey to select a drilling location. The local landfill wanted to install a well to provide them with water for dust control, and asked us to perform a resistivity survey and provide recommendations. The students had a lot of fun with the survey, and one of them interpreted the data for each station, but we ran out of time for the general interpretation and I ended writing the report myself.
- Gravity survey across a good size valley. We collected gravity data along a traverse 4 km long in an alluvial valley (fun) as well as an elevation profile (not fun). The goal was to determine the thickness of the alluvium, but we ended spending most of our time with the elevation survey, and at the end could not prove to ourselves that it was accurate enough for doing the terrain correction for proper gravity interpretation. Next time we will use a lidar survey of the valley and concentrate in the acquisition of gravity data and the subsequent modeling.
- Petroleum exploration lab. This exercise is in its infancy, and I would like to develop it into a petroleum exploration game (in the 80's such a game was developed, but I don't remember by whom). What I need is to get the structural maps of a district, preferably one that has a couple of different types of traps, as well as seismic reflection sections, geophysical borehole logs, and petroleum data. The idea is that students would buy a piece of data once a week (e.g., one well per section), interpret the limited data, and then bid with each other for a new well. Over a whole semester enough buyouts and mergers would take place that the final picture is developed. Maybe I will try this as the project for this workshop.
Two final thoughts: First, the limited mathematical ability of geology students is a real hindrance to tackling any "real life" problems. I designed a "Math for Geologists" class, but over the last four years I have been able to teach it only ones, because of low enrollments. Second, developing a problem-solving mentality is probably easier in a studio environment, such as used in the teaching of architecture. Unfortunately that is a model not commonly used in other disciplines, so being able to implement such a model, at least in my university, is unlikely.
An alternative would be to use case studies as lab assignments. To be realistic one would need access to investigation results and design drawings. Maybe this is an area where engineering companies could be asked to partner with applied geology programs.