AIRBORNE RESISTIVITY AND MAGNETOMETER SURVEY IN NORTHERN MAINE FOR OBTAINING INFORMATION ON BEDROCK GEOLOGY

Geophysical studies were conducted during September and October of 1975 in Northern Maine to locate rock types suitable for construction purposes for the proposed Dickey-Lincoln School Dam Project. Simultaneous airborne magnetometer and VLF electrical resistivity surveys were performed over an area of approximately 920 sq km surrounding the confluence of the St. John and Allagash Rivers. The resulting data were used to construct contour maps of apparent resistivity and of total magnetic intensity above the earth's background magnetic field. During the same time period, ground and multi-elevation surveys were performed over a special test sector of known geology. The ground and airborne study in the test sector aided in interpretation of the data by revealing a strong correlation between igneous geology, resistivity, and magnetic intensity. Lack of a similar correlation between resistivity and magnetic data in the remainder of the survey area suggested an absence of additional areas of igneous rocks. The multi-elevation survey of the test area indicated that changes in flight altitude, necessitated by the topographic relief encountered, would not seriously affect the regional resistivity patterns. Although there was no strong evidence of igneous rocks outside the test sector, suitable rock types may exist within the Dss geologic unit (cyclically bedded gray slate and sandstone) in the central part of the main survey area, where most of the high resistivity contours occur. /Author/

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/TaskA2Unit003
• Corporate Authors:

  U.S. Army Cold Regions Research and Engineering Laboratory

  72 Lyme Road
  Hanover, NH  United States  03755-1290
• Authors:
  • Sellmann, P V
  • Arcone, S A
  • Delaney, A J
• Publication Date: 1976-10

Media Info

• Features: Figures; Tables;
• Pagination: 24 p.

Subject/Index Terms

• TRT Terms: Aerial surveying; Bedrock; Contour maps; Dams; Data analysis; Geophysics; Igneous rocks; Mathematical analysis; Resistivity method
• Subject Areas: Geotechnology; Highways;

Filing Info

• Accession Number: 00145185
• Record Type: Publication
• ISBN: Task A2, Unit 003
• Report/Paper Numbers: CRREL Report 76-37
• Files: TRIS
• Created Date: Mar 30 1977 12:00AM