Skip to Main Content
Skip Nav Destination
GEOREF RECORD

Role of ductile shearing in the concentration of radon in the Brookneal Zone, Virginia

Alexander E. Gates and Linda C. S. Gundersen
Role of ductile shearing in the concentration of radon in the Brookneal Zone, Virginia
Geology (Boulder) (May 1989) 17 (5): 391-394

Abstract

A positive correlation exists among surface gamma radiation, uranium concentration, and the angles between C and S bands in mylonite and radon in the soils overlying the Brookneal zone of the southwest Virginia Piedmont. Part of the Brookneal zone lies within the compositionally homogeneous Melrose granite, which is undeformed to the west of the zone. The angle between C and S bands in mylonitic Melrose granite varies from 43 degrees in the westernmost protomylonite to near 0 degrees in the easternmost ultramylonite. Radon in the overlying soils increases from 450 picocuries/litre (pCi/L) in undeformed granite to as much as 4100 pCi/L in ultramylonite. In undeformed granite, uranium is hosted in titanite and zircon. During mylonitization, uranium was redistributed into the foliation and is associated with hematite and fine-grained monazite. Uranium, however, is in constant proportion to thorium, indicating little introduction of new uranium into the mylonite zone. An increase in the uranium concentration from 1 to 2 ppm in undeformed granite to 7 to 8 ppm in ultramylonite may be the result of volume loss during shearing.


ISSN: 0091-7613
EISSN: 1943-2682
Coden: GLGYBA
Serial Title: Geology (Boulder)
Serial Volume: 17
Serial Issue: 5
Title: Role of ductile shearing in the concentration of radon in the Brookneal Zone, Virginia
Affiliation: Rutgers Univ., Dep. Geol., Newark, NJ, United States
Pages: 391-394
Published: 198905
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 32
Accession Number: 1989-035102
Categories: Structural geologyGeneral geochemistryEnvironmental geology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. sketch maps
N37°01'60" - N37°25'00", W79°27'00" - W78°49'60"
N36°43'00" - N37°15'00", W78°55'00" - W78°27'00"
N36°32'60" - N37°04'00", W79°13'00" - W78°37'60"
Secondary Affiliation: U. S. Geol. Surv., USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute.
Update Code: 1989
Program Name: USGSOPNon-USGS publications with USGS authors
Close Modal

or Create an Account

Close Modal
Close Modal