Cosmogenic chlorine-36 reveals dates of the multiple prehistoric earthquakes that have produced a scarp on the Hebgen Lake fault. Apparent chlorine-36 ages are stratigraphically correct, follow a predicted theoretical pattern, and produce geologically reasonable model ages of 24, 20, 7.0, 2.6, 1.7, and 0.4 thousand years ago. This result demonstrates the feasibility of using cosmogenic chlorine...

Chlorine-36 is a long-lived and highly mobile radionuclide that has not historically received much attention. In recent years that has begun to change and there is particular current interest in the transport and fate of Cl-36 in the environment. In September of 2006 ANDRA hosted an International Forum on Chlorine-36 in the Biosphere where models indicating that Chlorine 36 will be a significan...

Introduction: The search for the former existence in the Early Solar System of the now extinct radionuclide Cl (T1⁄2 = 3x10 a) has proven to be difficult [e.g., 1]. This is at least partly due to the volatility of chlorine and the fact that in primitive meteorites Cl occurs in high abundance only in alteration phases such as sodalite (Na8Al6Si6O24Cl2). 36-Cl decays to both Ar by β decay (98.1 %...

Perchlorate (ClO4(-)) is ubiquitous in the environment. It is produced naturally by atmospheric photochemical reactions, and also is synthesized in large quantities for military, aerospace, and industrial applications. Nitrate-enriched salt deposits of the Atacama Desert (Chile) contain high concentrations of natural ClO4(-), and have been exported worldwide since the mid-1800s for use in agric...

Chlorine-36 is produced in rocks exposed to cosmic rays at the earth surface through thermal neutron activation of 35C1, spallation of 39K and 't°Ca, and slow negative muon capture by 4°Ca. We have measured the 36C1 content of 14C-dated glacial boulders from the White Mountains in eastern California and in a 14C-dated basalt flow from Utah. Effective, time-integrated production parameters were ...

Argon analysis on samples of sodalite from Dungannon, Ontario reveals an excess of 36Ar from neutron capture on 35C1 and excess 40Ar from the decay of 40K. These results indicate an average production rate of 5.6 X 102 atoms of 3®C1 per year per gram of chlorine over the age of the mineral. 3 .9X 108 yrs. The surface residence time of chlorine-rich rocks may be determined from the amounts of 36...