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Trenching as an exploratory method

Allen W. Hatheway and F. Beach Leighton
Trenching as an exploratory method
Reviews in Engineering Geology (1979) 4: 169-195


The critical nature of siting nuclear power plants has led to increased emphasis on exploratory trenching. Trenching is the most definitive of all subsurface exploratory methods; it permits inspection of a continuous geologic section by both geologists and regulatory authorities and makes possible the preparation of a graphic log that delineates both obvious and subtle geologic features. About one of every two nuclear plant licensing efforts utilizes exploratory trenching. Many geologic hazards, such as "capable" faults, can be detected from trench exposures; they may otherwise remain undetected. Trenches must be judiciously located, survey-controlled, excavated safely and adequately shored, logged in detail, and properly diagnosed. Useful techniques of trench logging include thorough cleaning of the trench walls, teamwork between geologist and recorder, logging against a carefully surveyed baseline and vertical reference grid, and panoramic photography. Soils, including paleosols, and glacial and glaciofluvial deposits present some of the most difficult media to log. Trench logs must be thoroughly interpreted and correlated so that they document the geologic conditions governing suitability of the site. Age-determination techniques utilized in exploratory trenching include petrographie analyses, quartz inclusion studies, clay mineralogie analyses, and radiometric methods.

ISSN: 0080-2018
EISSN: 2169-799X
Coden: GAEGA4
Serial Title: Reviews in Engineering Geology
Serial Volume: 4
Title: Trenching as an exploratory method
Affiliation: Haley Aldrich Inc., Cambridge, MA, United States
Pages: 169-195
Published: 1979
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 48
Accession Number: 1981-013408
Categories: Engineering geology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: tables, sect., plates, geol. sketch maps
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 1981
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