Abstract
When a geologist sets up a geologic model, various types of disparate information may be available, such as exposures, boreholes, and (or) geophysical data. In recent years, the amount of geophysical data available has been increasing, a trend that is only expected to continue. It is nontrivial (and often, in practice, impossible) for the geologist to take all the details of the geophysical data into account when setting up a geologic model. We have developed an approach that allows for the objective quantification of information from geophysical data and borehole observations in a way that is easy to integrate in the geologic modeling process. This will allow the geologist to make a geologic interpretation that is consistent with the geophysical information at hand. We have determined that automated interpretation of geologic layer boundaries using information from boreholes and geophysical data alone can provide a good geologic layer model, even before manual interpretation has begun. The workflow is implemented on a set of boreholes and airborne electromagnetic (AEM) data from Morrill, Nebraska. From the borehole logs, information about the depth to the base of aquifer (BOA) is extracted and used together with the AEM data to map a surface that represents this geologic contact. Finally, a comparison between our automated approach and a previous manual mapping of the BOA in the region validates the quality of the proposed method and suggests that this workflow will allow a much faster and objective geologic modeling process that is consistent with the available data.
References
- , 2012, Airborne electromagnetic mapping of the base of aquifer in areas of western Nebraska: U.S. Geological Survey Scientific Investigations Report 2011-5219.
- , 2013, Large scale mapping of groundwater resources in India with results from test sites in different geological terrain:
13th SAGA Biennial Conference & Exhibition October 2013, Conference Contribution . - , 2006, Determination of canal leakage potential using continuous resistivity profiling techniques, interstate and tri-state canals, Western Nebraska and Eastern Wyoming, 2004: U.S. Geological Survey Scientific Investigations Report 2006-5032.
- , 2006, Pattern recognition and machine learning: Springer.
- , 2006, Cooperative hydrologic study cohyst, hydrostratigraphic units and aquifer characterization report, http://cohyst.dnr.ne.gov/document/dc012hydro_aquifer_022406.pdf, accessed 2 June 2009.
- , 2010/12, Geological and energy implications of the Paterson Province airborne electromagnetic (AEM) survey, Western Australia: Record-Geoscience Australia.
- , 2016, Uncovering the groundwater resource potential of Murchison Region in Western Australia through targeted application of airborne electromagnetics:
25th International Geophysical Conference and Exhibition , ASEG-PESA-AIG,459–464 . - , 2003, Simultaneous 1D Inversion of loop-loop electromagnetic data for magnetic susceptibility and electrical conductivity: Geophysics, 68,
1857–1869 , doi:10.1190/1.1635038 .GPYSA7 0016-8033 - , 2017, Smart Interpretation — Automatic geological interpretations based on supervised statistical models: Computational Geosciences, doi:
10.1007/s10596-017-9621-8 . - , 2015, Processing and data merging report of Tellus airborne geophysical datasets, 2012–2015: Technical Report, Geological Survey of Ireland.
- , 2010, Den nationale grundvandskortlægning i Danmark — faglige resultater fra 2010: Technical Report, Geological survey of Denmark and Greenland.
- , 2011, A trans-dimensional Bayesian Markov chain Monte Carlo algorithm for model assessment using frequency-domain electromagnetic data: Geophysical Journal International, 187,
252–272 , doi:10.1111/j.1365-246X.2011.05165.x .GJINEA 0956-540X - , 1999, Estimating depth of investigation in DC resistivity and IP surveys: Geophysics, 64,
403–416 , doi:10.1190/1.1444545 .GPYSA7 0016-8033 - , 2014, The integrated ground water mapping concept of Denmark transferred to Thailand: Presented at the
8th Annual Meeting DWRIP . - , 2009, Helicopter electromagnetic and magnetic geophysical survey data for portions of the North Platte River and Lodgepole Creek, Nebraska, June 2008: U.S. Geological Survey Open-File Report
2009–1110 . - , 2010, Helicopter electromagnetic and magnetic geophysical survey data, portions of the North Platte and South Platte natural resources districts, Western Nebraska, May 2009: U.S. Geological Survey Open-File Report 2010-1259.
- , 2000, Morrill County test-hole logs: Nebraska Water Survey Test — Hole Report No. 62, Conservation and Survey Division, Institute of Agriculture and Natural Resources, University of Nebraska–Lincoln,
106 . - , 2002, Hydrologic characteristics of selected alluvial aquifers in the North Platte natural resources district, Western Nebraska: U.S. Geological Survey Water-Resources Investigations Report 2001-4241.
- , 1985,
Cenozoic paleography of the western Nebraska , in R. M. FloresS. S. Kaplin, eds., Cenozoic Paleogeography of West Central United States: Rocky Mountain Section, SPEM,209–229 . - , 2001, Interaction of surface water and ground water in the Dutch Flats area, western Nebraska, 1995–1999: U.S. Geological Survey Water-Resources Investigations Report 01-4070.
