440 B0WE2S AXD AUROUSSEAU FUSION OF SEDIMENTARY ROCKS 



stage was a twisting of tlie rock contents of the core barrel on the rock 

 immediately below it and of adjacent layers of the core material on each 

 other. To such action rather than to the turning of steel on rock is to 

 be assigned the larger measure of production of heat required for the 

 fusion that resulted. 



We may get an approximate figure for the heat produced by friction, 

 since the pressure resting on the core and the rate of revolution are 

 known with fair accuracy. The pressure was about 20 tons, the rate of 

 revolution 25 per minute, the radius of gyration 1.5 inches, and the 

 coefficient of friction of rock matter on rock may be as great as 1 or even 

 greater.^ Taking a coefficient of friction of 1, it is found that about 

 3.14 X 10"^ foot-pounds of work would be expended in friction at or 

 near the end of the core barrel in the 40 minutes during which very slow 

 progress was made. This is equal to about 10'^ calories. Assmning a 

 specific heat of 0.22 calorie for the material heated and a latent heat 

 of 100 calories per gram, the amount of heat developed is sufficient to 

 raise to 1,100 degrees and partially fuse (50 per cent couA^ersion to 

 liquid) about 37 kilos of rock. Only about 6 kilos of rock actually 

 were so affected. Of course, all the heat generated would not be avail- 

 able for this effect. Some of it would be used in heating the surrounding 

 rock, but this amount would probably not be great on account of the 

 poor conductivity of rock, especially when porous. A large amount would 

 be conducted away by the massive pipe line, but even this good conductor, 

 with the tip heated to 1,100 degrees centigrade and a temperature of 

 100 degrees centigrade only 20 centimeters higher up the pipe, would 

 carry away but 200 calories per second. The friction is caj)able of pro- 

 ducing about 4,000 calories per second. It is not unreasonable to expect, 

 then, that, of the heat j^roduced, a sufficient quantity was available to 

 melt 6 kilos of rock. 



Core from "Meyer 6"' Well of the Union Oil Company 



This well is located at Santa Fe Springs, Los Angeles County, Cali- 

 fornia. Professor Willis sent us part of the fused end of another core 

 from the above-named locality, obtained at a depth of about 3,000 feet. 

 No sample of the unfused sediment is a^^ailable for comparison in this 

 case ; but, though much glass is formed, it is plain that the original was 

 an arkose-like material of considerably coarser grain than the Montezuma 

 sediment. The unfused grains are again quartz and plagioclase (about 



^ Peele's Mining Engineers' Handbook, p. 1901. 



