4?o 



ON THE NEWEST FLGETZ-TR.AJ?' 



transition, independent coal, and newest floetz- 

 trap formation. As two of these formations had 

 been previously noticed by Professor Jameson, I 

 confined my observations more particularly to the 

 rocks of the trap formation, which I had an oppor- 

 tunity of ascertaining to be superincumbent upon 

 all the other rocks of the extensive district which 

 I examined, and to be situated in an overlying 

 and unconformable position, immediately upon 

 strata of the independent coal; from which it is 

 sufficiently manifest, that this class of rocks is the 

 newest, or of posterior formation to all the others, 

 a point upon which the two prevailing geological 

 theories do not disagree. 



Some important remarks were introduced, rela- 

 tive to the oryctognostical alliances of the diffe- 

 rent members of this series of rocks, the order in 

 which these invariably followed each other, and 

 the variety of interesting transitions to be obser- 

 ved in this portion of the trap formation. I took 

 occasion to mention, that in every instance where 

 there occurred an opportunity of examining the 

 series, and approaching near to the subjacent stra- 

 ta,- there was uniformly found, as the lowest or 

 oldest member, a coarse conglomerate rock, con- 

 sisting of fragments of different minerals of ante- 

 rior origin ; that this substance graduated into 

 amygdaloid, which, in its turn, either passed at 

 once into basalt, or, in some instances, first through 



