Nature 342, 906 - 908 (28 December 1989); doi:10.1038/342906a0

A helium isotope transect along the Indonesian archipelago

D. R. Hilton^* & H. Craig

Isotope Laboratory, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093, USA
^*Present address: Free University of Berlin, FB 24, FR Geochemie, Boltzmannstrasse 18–20 1000 Berlin 33, FRG

HELIUM isotope studies^1,2 have identified the Banda arc section of the Indonesian archipelago as the only circum-Pacific volcanic arc with ³He/⁴He ratios significantly lower than the common ratio in mid-ocean-ridge basalts (MORB). In eleven of twelve circum-Pacific arcs, MORB-like ³He/⁴He ratios show that helium in these volcanic terrains is dominantly primordial helium from the mantle wedge above the sinking slab, rather than radiogenic helium from subducting oceanic crust or sediments. Only in the Banda arc have significantly lower ratios been observed, corresponding to as much as 80% radiogenic helium from subducting continental material². We now report ³He/⁴He measurements along a 1,800-km section of the Sunda arc, a region of underthrust oceanic lithosphere, showing MORB-like ratios from western Java to a surprisingly sharp transition zone centred on Lomblen Island, where the low ratios of the Banda arc begin. Our results confirm the prediction² that Sunda arc volcanoes should have MORB-like ³He/⁴He ratios, with a well-defined transition to the much lower Banda arc ratios near Lewotolo volcano, and demonstrate a remarkable linkage of helium isotope variations with tectonic processes not readily discernible with trace elements or other isotopes.

References

1.	Craig, H., Lupton, J. E. & Horibe, Y. in Terrestrial Rare Gases (eds Alexander, E. C. & Ozima, M.) 3−16 (Japan Sci. Soc, Tokyo, 1978). | ChemPort |
2.	Poreda, R. J. & Craig, H. Nature 338, 473−478 (1989). | Article | ISI | ChemPort |
3.	Katili, J. A. Tectonophysics 26, 165−188 (1975). | Article | ChemPort |
4.	Hamilton, W. U.S. Geol. Surv. Prof. Pap. 1078, 1−345 (1979).
5.	Katili, J. A. & Hartono, H. M. S. in Geodynamics of the Western Pacific-Indonesian Region (eds Hilde, H. C. & Uyeda, S.) 387−399 (Am. Geophys. Un., Washington, DC, 1983).
6.	Jezek, P. A. & Hutchinson, C. S. Bull. volcan. 41, 586−608 (1978). | ChemPort |
7.	Whitford, D. J., Nicholls, I. A. & Taylor, S. R. Contr. Miner. Petrol. 70, 341−346 (1979). | Article | ISI | ChemPort |
8.	Foden, J. D. & Varne, R. Chem. Geol. 30, 201−206 (1980). | Article | ChemPort |
9.	Wheller, G. E., Varne, R., Foden, J. D. & Abbott, M. J. J. Volcan. geotherm. Res. 32, 137−160 (1987). | ChemPort |
10.	Whitford, D. J. Geochim. cosmochim. Acta 39, 1287−1302 (1975). | Article | ChemPort |
11.	Varne, R. & Foden, J. D. in The Origin of Arcs (ed. Wezel, F. C.) 159−189 (1986).
12.	Whitford, D. J., Compston, W., Nichols, I. A. & Abbott, M. J. Geology 5, 571−575 (1977). | Article | ChemPort |
13.	Whitford, D. J., Foden, J. & Varne, R. Carnegie Inst. Wash. Ybk. 77, 613−620 (1978).
14.	Whitford, D. J. & Jezek, P. A. Contr. Miner. Petrol. 68, 141−150 (1979). | Article | ChemPort |
15.	Whitford, D. J., White, W. M. & Jezek, P. A. Geochim. cosmochim. Acta 45, 989−995 (1981). | Article | ChemPort |
16.	Stolz, A. J., Varne, R., Wheller, G. E., Foden, J. D. & Abbott, M. J. Contr. Miner. Petrol. 98, 374−389 (1988). | Article | ChemPort |
17.	Whitford, D. J. & Jezek, P. A. Bull. Geol. Soc. Am. 93, 504−513 (1982). | ChemPort |
18.	Neumann van Padang, M. Catalogue of the Active Volcanoes of the World. I: Indonesia xiii (Int. Vole. Ass., Napoli, 1951).
19.	Varekamp, J. C. et al. Netherlands J. Sea Res. (in the press).
20.	Nishimura et al. Bandung Geol. Res. Dev. Cent, Spec. Publ. No. 2, 105−114 (1981).
21.	McBride, J. H. & Karig, D. E. Tectonophysics 140, 265−273 (1987). | Article |
22.	Eva, C., Cattaneo, M. & Merlanti, F. Tectonophysics 146, 241−259 (1988). | Article |
23.	Nishimura, S. & Suparka, S. J. Southeast Asian Earth Sci. 1, 45−57 (1986).
24.	Silver, E. A. et al. Geology 13, 687−691 (1985). | Article | ISI | ChemPort |
25.	Van Bergen et al. Netherlands J. Sea Res. (in the press).
26.	McCaffrey, R., Molnar, P., Roecker, S. W. & Joyodiwiryo, Y. S. J. geophys. Res. 90, 4511−4528 (1985).
27.	Kurz, M. D., Jenkins, W. J., Schilling, J.-G. & Hart, S. R. Earth planet. Sci. Lett. 58, 1−14 (1982). | Article | ISI | ChemPort |
28.	Simkin, T. et al. Volcanoes of the World (Hutchinson Ross, Stroudsburg, 1981).