Rapidly-formed ferromanganese deposit from the eastern Pacific Hess Deep

W. C. Burnett; D.Z. Piper

doi:10.1038/265596a0

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Rapidly-formed ferromanganese deposit from the eastern Pacific Hess Deep

W. C. Burnett·D.Z. Piper

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Abstract

A thick ferromanganese deposit encrusting fresh basaltic glass has been dredged from the Hess Deep in the eastern Pacific. Contiguous layers within the Fe-Mn crust have been analysed for uranium-series isotopes and metal contents. The rate of accumulation of the deposit, based on the decline of uranium-unsupported 230Th, is calculated to be approximately 50 mm per 106 yr. Based on hydration-rind dating of the underlying glass and an 'exposure age' calculation, this rate is concluded to be too slow, and an accretion rate on the order of 1 mm per 103 yr is more consistent with our data. ?? 1977 Nature Publishing Group.

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W. C. Burnett, D.Z. Piper. 1977. Rapidly-formed ferromanganese deposit from the eastern Pacific Hess Deep. https://doi.org/10.1038/265596a0

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