3. Element recycling in volcanic arc systems (with Manfred vanBergen, Renee Poorter and Pieter Vroon, all from the Netherlands; Udo Fehn, University of Rochester, NY; Maddalena Pennisi, CNR, Pisa, Italy; Jim Luhr, Smithsonian Institution, DC). Radiogenic isotope systems of arc rocks in conjuction with sediment analyses provide insights into sediment recycling in volcanic arc systems. Our focus has been on the east Indonesian arcs and for me on carbon cycling. Recently, work on 129I and 36Cl abundances and d11B in volcanic fluids helps to decipher element recycling - both pathways and sources- in arc fluids. We are using d34S - S/Se in sulfates adsorbed on plinian ashes to trace the sulfur sources in arc volcanoes with high-sulfur magmas (Pinatubo, El Chichon).
Wesleyan students: Gari Mayberri '97

Publications:
Poorter, R.P.E., Varekamp, J.C., et al., 1991: Geochemistry and isotopic composition of volcanic gases from the Banda and Eastern Sunda arcs,  Indonesia, Geochim. Cosmochim. Acta 55, 3795-3807.

Varekamp J.C., Kreulen R., Poorter R.P.E. and VanBergen M.J. , 1992: Carbon sources of arc volcanism with applications for the carbon cycle. Terra Nova 4, Spec. Issue Global Change (ed. Wezel), 363-373.

Vroon, P.Z., Van Bergen, M.J.,  White W.M., and Varekamp, J.C., 1994: Sr-Nd-Pb isotope systematics of the Banda arc, Indonesia:Combined subduction and assimilation of continental material. J. Geophys. Res. 98, 22,349-22,366.

Hoogewerff, J.A., VanBergen, M.J., Vroon, P.Z., Hertogen, J., Wordel, R., Sneyers, A., Nasution, A., Varekamp, J.C., Moens, H.L.E., and Mouchel, D., 1997: U-series, Sr-Nd-Pb isotope and trace-element systematics across an active island arc-continent collision zone: Implications for element transfer at the slab-wedge interface. Geochimica Cosmochimica Acta, 61, p.1057-1072.

Fehn, U., Snijder, G. and Varekamp, J.C., 2000, Evidence for marine sediment recycling in subduction zones from 129I in crater lakes. J. Volcan. Geoth. Res., 115, 451-460.