Cosmogenic C-14 in carbonate rocks

The rate of in situ production of cosmogenic (CO)-C-14 in limestone is 18 /- 3 atom/g-CaCO3/year corrected to high latitude and sea level, based on m easurements of (CO)-C-14 in limestone associated with the Bonneville-Provo shoreline complex in Utah. In situ cosmogenic (CO)-C-14 was separated cryog enically from CO2 using C-14 - 'dead' CO as a carrier for in situ cosmogeni c (CO)-C-14. This rate of production was used to estimate an age of 4360 +/ - 1220 cal. year B.P. for the last movement on the South Oquirrh Mountain F ault Zone in northern Utah, and an age of at least 10,600 +/- 900 years for the penultimate event of the Pleasant Valley fault in northern Nevada. (C) 1999 Elsevier Science B.V. All rights reserved.