134 PECKHAM — THE GENESIS OF BITUMENS. [April 1, 



the products of the distillation of highly organized animal tissue, as 

 an effect of the accumulation of sediments, and of metamorphic ac- 

 tion upon unaltered sediments, through granite and gneiss to lava 

 and pumice. 



20. If we turn from North America to Europe-Asia, the testi- 

 mony of the most eminent observers seems equally convincing. 

 Daubree was satisfied that the origin of the bitumen was found in 

 metamorphism. Other French chemical geologists were equally 

 well-grounded in this belief. As early as 1835, M. Rozet read a 

 paper before the Societe Geologique de France in which he dis- 

 cussed the occurrence of asphaltic limestone at Pyrimont. He says, 

 " The bituminous matter is found equally in the calcareous rock 

 and the molass that covers it. It is evident the action that intro- 

 duced it into the two rocks is posterior to the deposition of the 

 latter. The manner in which it is distributed in great masses, 

 which throw their ramifications in all directions, joined in such a 

 manner that the superior portions generally contain less bitumen 

 than the remainder of the mass, indicate that the bitumen has been 



sublimed from the depths of the globe It may be objected 



that such basaltic rocks do not appear in all the extent of the 

 Jura. To that I reply that they are found in the neighborhood, in 

 Burgundy and in the Vosges and further, that in the changes in the 

 surface of the soil, whether occasioned by fractures or by the disen- 

 gagement of vapors, the plutonic rocks do not necessarily appear at 

 the surface. Perhaps in the deep valleys of the Jura the basalts 



are of very slight depth In the Val de Travers, near Neuf- 



chatel, similar phenomena are observed."^ 



In 1846, Mr. S. W. Pratt associated the occurrence of bitumen 

 at Bastennes with the eruption of ophite in the Pyrenees.''^ In 1854, 

 M. Parran remarks concerning the occurrence of bitumen in the 

 environs of Alais, ''whatever be the origin of these substances, 

 whether they be due to interior emanations from fissures of disloca- 

 tion or to circumstances exterior and atmospheric, it is evident that 

 there was during the Tertiary period an asphaltic epoch in relation 

 to which it is convenient to recall the numerous eruptions of tra- 

 chytes and basalts which characterize that period, and have prob- 

 ably acted by distillation upon masses of combustibles hidden in 



'^Bull. Geol. Soc. de France (i), vii, 138. 

 "^Qiiar. Jour. Geol, Soc, ii, 80. 



