Figure F34. Interpretative summary diagram for Site 1139 showing 19 igneous units that include trachytic to rhyolite volcanic and volcaniclastic rocks and basaltic to trachytic lava flows. In general, the primary vesicularity of the lava flows and marginal breccias is obscured by the effects of alteration. Sanidine xenocrysts are distributed throughout the more mafic flows. Although changes in potassium concentration from downhole natural gamma measurements correlate generally with the defined igneous units, the logging data show more complexity, indicating unrecovered changes in lithology.