Naumann on Primitive Formations, 261 



the inference that the succession of the primitive rocks in a down- 

 ward direction, corresponds to their age from oldest to youngest, 

 because it was, of course, through a solidification from the outside 

 inwardly, that the strata in question were formed, (Lehrbuch I, 

 489). The only way of explaining the origin of the newer cryp- 

 togenous rocks, left to the supporters of this hypothesisi, is to 

 suppose that their material has been protruded from the interior 

 through the earth's crust in an eruptive form. 



The most considerable difficulties which this hypothesis has to 

 contend with, arise from the relations of the structure of the prim- 

 itive formations, and from the mineralogical character of certain 

 of the rocks belonging to it. Whether these difficulties can be 

 explained away by the supposition of a hydro-pyrogenous devel- 

 opment of the outside'part of the primitive solidified crust, as in- 

 dicated by Angelot, Rozet, Fournet, Scheerer and others, we must 

 leave undecided in the meantime. Scheerer attempted, in a pe- 

 culiar manner, to overcome the difficulties which the structure 

 and architecture of the gneiss present. He regards them as an 

 original phenomenon, produced during the solidification itself, 

 by the action of electro-magnetic currents ; and comes to the 

 final conclusion, " that the primitive formations, with all the di- 

 versity of their rocks, are only to be regarded as the first hardened 

 crust of the solidifying earth." If the vertical position of the 

 primitive gneiss strata, as displayed in their parallel-zoned, 

 fan-shaped and gable-formed architecture, is really to be looked 

 upon as their original position, then the verdict which Kittel 

 thus expressed, must be pronounced correct : " so long as a hy- 

 pothesis is unable thoroughly to explain the almost vertical posi- 

 tion of the primitive strata, it cannot be regarded as even approx- 

 imately near the truth." (Skizze der geogn. Verhaltnisse von 

 Aschafi'enburg, p. 40). 



Scheerer concludes from the contortions and undulations of 

 the gneiss layers, that the primitive rocks must have originally 

 been in a soft, plastic state, and MaccuUoch, even earlier, ar- 

 rived at the same conclusion, from the surprising contortions of the 

 mica-schist, which he compared with similar windings in the 

 structure of certain basalts. There is probably nothing to be said 

 against the correctness of this deduction, which receives complete 

 confirmation from the so frequently occurring elongation of the 

 constituent of gneiss and other primitive rocks. But whether this 

 plastic condition has been occasioned by high temperature alone, 



