10Be and 14C in the Earth system

In a very short period of time, 10Be data have significantly improved our knowledge in various fields of Earth and planetary sciences. Examples are: (a) solar modulation of isotope production, revealed in 10Be ice-core profiles; (b)geomagnetic m odulation of isotope production, revealed in 10Be ice-core (from the past 10 ka) and ocean-sediment profiles (geomagnetic reversals); (c) climatic effects reflected in 10Be profiles in loess and polar ice cores (10Be behaviour in atmosphere); (d) comparison of 10Be and 14C variations (tree rings) from carbon-cycle models and inform ation on ocean circulation history from 14C m easurements on benthic and planktonic Foram inifera in ocean sediments. An overview on work in collaboration with the Zurich AMS facility (with Professor W. Wolfli) is given.