126 PECKHAM — THE GENESIS OF BITUMENS. [April!, 



lence. It is true that the local effects of such phenomena as the 

 earthquakes at Lisbon and Java and the Red River fault appear cata- 

 clysmic ; yet these effects are microscopic when compared with the 

 dimensions of the eartli, and may have been, nay, probably were 

 the culmination of a series of movements that had been in progress 

 for immense intervals of time. I therefore believe that in stating 

 the causes of those changes that have taken place at the surface of 

 the earth as we now know it, one of the most important considera- 

 tions is the unlimited periods of time through which the pressure 

 due to accumulation of sediments and the consequent development 

 of heat has acted upon those sediments, which in many instances 

 were filled with water charged with mineral matter in solution. From 

 the combined action of pressure, heat and steam, tlirough unlimited 

 periods of time, the constituent elements of sediments have been 

 brought into every possible state of combination, from obsidian and 

 pumice, which have been completely fused, through lavas, granites, 

 gneisses, etc., to sediments in which there has been no change at all. 

 As Dr. Hunt has fully shown, the action of thermal waters, which have 

 •been largely instrumental in producing these changes, has been often 

 extremely localized both laterally and vertically, and may be greatly 

 varied by the constituents of the sediments themselves. 



15. If, then, we accept the hypothesis that all of the rocks as we 

 now know them are sediments, whatever may be their present condi- 

 tion, we are forced to the conclusion that life first appeared upon the 

 planet at a date too remote to be determined even in geologic time, 

 and that the remains of organic forms have practically been a con- 

 stant constituent of sediments from that time to the present. As 

 might be expected, we find organic remains in every possible condi- 

 tion, from crystallized graphite to unaltered cellulose. Vegetable 

 and animal remains are found in every conceivable condition of 

 replacement and alteration. We find pseudomorphism in the strict- 

 est sense as well as metamorphic action developed in every possible 

 degree. Nor can we assert that any of the older strata are free from 

 such action, for metamorphism is, as the word signifies, a change of 

 form, and no limits can be assigned to such change in either time, 

 place or degree that are not arbitrary. There can be no question 

 that as sediments have accumulated slowly so these changes have 

 progressed slowly. 



Nevertheless, following upon long periods of quiet, there appear 

 to have been periods of cataclysmic violence, as when the vast lava 



