Mohave County miner., 1915-03-27

WIS ndQ plnneQ our ldlIH Io Ine pres ence of water in volcanic rock, they did not convince us. The old-time views seemed so thoroughly grounded that we awaited confirmation of Mir. Brun's results.
 In 1912, Dr. A. P. Day and his as- sociate Dr. E. S. Shepherd, of the Carnegie Geophysical Laboratory, in Washington, spent some months at the lake of fire in the crater Kilauea of the Hawaiian Islands. MT. Brun had also visited this volcano and had based some of his most sweeping statements upon the results of his experiments there. By lucky coincidence, during the stay of Messrs. Day and Shepherd dome of solidified lava developed on the solid flat short distance from the great pool of molten rock. It was possible to approach this dome within which the molten lava was boiling and emitting gases. A short iron tube was pushed through crevice and was con- nected with a series of hard-glass tubes, terminating in 20 condensing glass reservoirs, each holding about half liter. At the far end was pump by which the gases were at once pumped through these series of pipes and condensers so as to furnish samples for analysis. The pumping was con- tinued for some time in order to drive out the air already in the tubes, but scarcely had the pump been set in operation before water began to con- dense in the tubes and the reservoir. In the end, as much as 100 c. c. were condensed in a tube having a total volume of 800 c. c.
 When the Geological Society of America met in New Haven during the Christmas holidays of 1912, Dr. Day addressed the geologists present. He told of his trip to the Hawaiian Islands, and reviewed very carefully, and at length, the experiments and conclusions of MT. Brun. The audience could not tell, during all his preliminary remarks, what results he had to announce. When, however, he had worked us up to a suitable climax, and produced from behind the desk one of his tubes with 100 c. c. of volcanic water in it, visible to us all, know that, for one, great load was lifted from my mind. Since these experiments we have had no doubt about the existence of copious amounts of magmatc waters, and we can not but believe that the deep-seaI- ed magmas are often richly provided with them. They are doubtless more abundant in the magmas high in silica but they do not fail in the basic ones. If such a mass of molten rock we'll provided with gases and fairly deep below the surface is forced into the midst of other rocks; and if it slowly cools and crystallizes to anhydrous silicates, the contained water must be evicted. We have thought that the gases and associated water pass up- ward and outward, perhaps through an already cooled and cracked shell of the igneous rock, and that then they play an important part in the circulation of the ground-waters.
 From another significant quarter the evidence has been accommodating. All mining engineers of extended ex- perience in the field know how often ore deposits are found at the contact of igneous rocks with rocks of sedi- mentary nature, and especially with limestones. In the Southwest and Mexico contact deposits are innumer- able. The old-time view regarding their formation was that the contact zones were produced from impure beds in the limestone, by the influence of igneous rock. If, for instance, in ad- dition to the carbonates of lime and magnesia, a bed contained silica, alumina, and some iron oxide, the silica, under the influence of heat, would combine with alumina and with lime or magnesia and such iron as was present, to produce lime silicates and lime -alumina silicates. We came to use definite name for this group of