ROCK FAULTS.
On page 295 we stated our inability to account for a certain class of rock faults, shown in figure 110, in which the rock occupies narrow walls across the plane of the coal, sometimes only a few feet in`thickness, dividing the coal in the form of a dike, and yet not injuring the size of the bed or the quality of the coal. We find the coal on each side of these peculiar faults perfectly pure, but abruptly ter minating against the face of the fault. These faults rarely extend above or below the coal. They simply divide the bed, and are always composed of the same material, whether slate or rock, which forms the "roof" or strata covering the coal-bed.
In tracing the evidence offered by existing facts, to prove that mineral coal is the result of petroleum, or a solidified hydro-carbon, we find the rock faults alluded to satisfactorily explained by the fact that the bitumen resulting from the evaporation of the lighter portions of petroleum on the surface of the water, frequently exhibit cracks or fissures across its surface for great distances, as shown by the pitch lakes of Trinidad and other places.
These cracks or fissures would naturally become filled with earthy matter, and form the rock faults just as we find them.
No other theory can satisfactorily account for the peculiar faults herein discussed, and the natural and clear explanation thus afforded offers another proof of the formation of our coal-beds from the condensed hydrocarbon. With the facts now before us, and the vast amount of evidence gathered in our patient and laborious investigation of this subject during the two years we have devoted to this work, we could now present our theory of the NATURAL PROCESSES, and the formation of mineral coal, much more clearly and satisfactorily than they have been presented in COAL, IRON and on., but we must now let it stand as written. We did not set down to prove a peculiar theory, but the theory grew into shape and being, by the facts which were developed by a close investigation, and by thirty years of former experience and extensive practical observation.