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|Title:||Assessment of geophysical methods for subsurface geologic mapping, Cluster 13, Edgewood Area, Aberdeen Proving Ground, Maryland|
|Authors:||Geological Survey (U.S.)|
Installation Restoration Program (U.S.)
Aberdeen Proving Ground (Md.). Directorate of Safety, Health, and Environment.
Butler, Dwain K.
Sharp, Michael K.
Sjostrom, Keith J.
Simms, Janet E.
Llopis, José L.
Fitterman, David V.
|Keywords:||Borehole geophysical logs|
Aberdeen Proving Ground
|Publisher:||Geotechnical Laboratory (U.S.)|
Engineer Research and Development Center (U.S.)
|Series/Report no.:||Technical report (U.S. Army Engineer Waterways Experiment Station) ; GL-96-17.|
Abstract: Seismic refraction, electrical resistivity, and transient electromagnetic surveys were conducted at a portion of Cluster 13, Edgewood Area of Aberdeen Proving Ground, Maryland. Seismic refraction cross sections map the "topsoil" layer and the water table (satuated zone). The water table elevations from the seismic surveys correlate closely with water table elevations in nearby monitoring wells. Electrical resistivity cross sections reveal a very complicated distribution of sandy and clayey facies in the upper 10--15m of the subsurface. A continuous surficial (topsoil) layer correlates with the surficial layer of the seismic section and nearby boring logs. Below the surficial layer, the complicated facies distribution has resistivities ranging from 25 ohm-m (likely clay) to several thousand ohm-m (dry sands and/or grovels). The complexity and details of the electrical resistivity cross section correlate well with boring and geophysical logs from nearby wells. The transient electromagnetic surveys map the Pleistocene-Cretaceous boundary, the saprolite, and the top of the Precambrian crystalline rocks. Conducting the transient electromagnetic surveys on a grid pattern allows the construction of a three-dimensional representation of subsurface geology (as represented by variations of electrical resistivity). Depths to the Cluster 13 and other areas of the Edgewood Area. Thickness and depth of the saprolitic layer and depth to top of the Precambrian rocks are consistent with generalized geologic cross sections for the Edgewood Area and depths projected from reported depths at the Aberdeen Proving Ground NW boundary using regional dips.
|Rights:||Approved for public release; distribution is unlimited.|
|Appears in Collections:||Documents|