COLORED LAVA FLOWS ON THE EARTH: A WARNING TO IO VOLCANOLOGISTS

David A. Rothery, Andrew J. L. Harris, and Martin J. Wooster

Department of Earth Sciences, Open University, Milton Keynes, England

Tanya L. Babbs

Department of Geology, Leicester University, Leicester, England



Abstract.  Pale coatings of amorphous silica, sulfur, and sulfur-bearing

compounds can form on terrestrial basalt flows while they are still active and

subsequently on timescales ranging from days to years after the eruption. We

cite examples below from Kilauea (Hawaii), Etna (Sicily) and Cerro Negro

(Nicaragua) and caution against undue reliance on spectral reflectance to

determine the bulk properties of lava flows on Io, where sulfur and/or sulfur

compounds are likely to dominate comparable (but probably more widespread)

coatings.