Gosse 9526774 This proposal requests support for an international, multi-disciplinary, and multi-purpose workshop on the production rates of cosmogenic nuclides in terrestrial rocks, to take place at Los Alamos National Laboratory, New Mexico, February 2-4, 1996. The goals of this workshop are: to gather those of us who are working to determine this production rates of terrestrial cosmogenic nuclides with those working in fields that are useful to this undertaking. This includes scientists whose principal interests and expertise include: geology and geochronology; accelerator and conventional mass spectrometry; nuclear and analytical chemistry paleomagnetism and geomagnetic dipole field intensity research; the influence of solar activity on cosmic rays; and calibration of the 14C timescale. to provide a forum in which to discuss A) measurements of production rates, B) models relating to cosmic-ray intensity and nuclear cross sections to production rates, C) the current state of knowledge concerning temporal and spatial variability of productio rates. to assemble recommendations that help steer and focus future efforts to calibrate cosmogenic nuclide surface exposure data methods. to compile an annotated bibliography of current relevant publications with evaluation. More than forty invited speakers will present papers. Discussions on specific topics and general discussions will occur throughout the three days. Lessons learned and recommendations for future research will be published along with the abstracts and an annotated bibliography of most relevant publications. The terrestrial cosmogenic nuclide time scale, like the conventional radiocarbon time scales, needs to be calibrated to the true (calendric) time scale. While the cosmogenic techniques are in their infancy and as the number of geological applications of cosmogenic nuclide exposure dating rapidly increases, this workshop is necessary and timely. The recent call (Clark and others, in review) to change by 17% the pre vious 10Be (and other nuclides) production rate estimate (Nishiizumi et al., 1989) for -13 kyr of exposure is just one example of the urgent need of this workshop. The proposed workshop will be share-supported between NSF and Los Alamos National Laboratory and the Institute of Geophysics and Planetary Physics. Funds from NSF are requested for participant support and publication costs. No NSF funds will be used for salaries or for support of foreignn participant travel or participants who are employees of LANL.
