My conclusion in regard to the origin of this coarse black ash is that it probably originated in at least three craters—Tantalus, the pond east of Kakea, and Punchbowl. The other shore craters, Diamond Head and the Kokos, have poured out freely a similar hut finer grained material, and Makalapa may have been the source of the consolidated ash plant beds near Halawa. A better knowledge of the conditions about Diamond Head leads to the belief that the ash on its eastern side came from Kupikipikio. There are beds of this ash cut by the road on the northeast and north sides of the Head, sloping toward the east. A part of the material has changed its color from black to reddish, due to weathering. It is generally much finer grained than the ash about Honolulu. It has not been observed about Diamond Head elsewhere than on the Kupikipikio side, where it would have naturally fallen if ejected from the latter opening, being carried by the prevailing winds so as to fall upon the slope of the former. So also had the material come from Diamond Head we should expect to find some remnants of it at least upon the leeward side.
The position of Kupikipikio may be better understood by noticing the dark promotory in the distance in Plate 9B taken from high up the Head, and showing the eastern rim of the crater as well.
Chemically this ash ought to correspond to the composition of basalt. The black color may be due to its ferrous content or to grains of magnetite. Scattered through it are white veins and irregular masses in upright stems not unlike the roots of trees. As white particles are also indiscriminately disseminated, their bunching together is probably a concretionary action. Dr. AYH cox of the U. S. Experiment Station, says there is much potassium in this ash, perhaps enough to be of value to growing crops. Some of the white bunches may be potassium silicates, allied to massive zeolites ; while most of them are undoubted calcium car bonates probably derived from the underlying coral reefs.