298 HISTORY OF GEOLOGY AND PALEONTOLOGY. 



The founder of the newer theories of upheaval was without 

 doubt James Hutton, the Scottish geologist. According to 

 Hutton, the earth's internal heat caused the rocks to expand 

 and to find relief by bulging upward; thus portions of the 

 earth's surface rose above sea-level and formed continents and 

 mountains; volcanoes provided a means of exit for the hot 

 vapours and molten masses of rocks, and prevented the 

 excessive expansion and upheaval of the earth's crust. 

 Although Hutton's theory of expansion and elevation was at 

 first little considered, a number of observers like Fichtel and 

 Pallas arrived at similar conclusions from independent re- 

 searches, while De la Beche, Babbage, Lyell, and Poulett-Scrope 

 accepted the theory and extended it in various directions. 



Leopold von Buch was an enthusiastic supporter of the 

 Huttonian theory. In the year 1812, J. L. Heim had 

 assigned to basalt an important role in the elevation of 

 mountain-chains. Von Buch ten years later, after his studies 

 in South Tyrol, became convinced that the dolomite was an 

 altered limestone, the transformation having been effected by 

 the action of volcanic magnesian vapours during the protrusion 

 of augite porphyry. From the stratigraphical relations of the 

 sedimentary rocks and their association with the augite 

 porphyry, Buch developed his well-known theory that the 

 whole Alpine system followed the direction of an enormous 

 fault, through which augite porphyry had locally escaped at 

 the surface, and had elevated, tilted, and folded the 

 neighbouring rocks. The results obtained in South Tyrol 

 were then applied to Thuringia and the Harz, and finally the 

 hypothesis was expressed that all mountain-chains had been 

 upheaved by augite porphyry. 



The disciples of Buch found in the theory of eruptivity 

 and consequent disturbance of strata a complete explanation 

 of all possible complications of crust-deformation, and for a 

 time the upheaval of mountains was ranked as a volcanic 

 phenomenon. Poulett-Scrope in 1825, in his work On Vol- 

 canoes^ supported Hutton's Plutonic doctrine, and entered into 

 an elaborate investigation of the ascent of intrusive granite and 

 porphyritic masses in relation to the tectonical effects produced 

 upon the different kinds of rock-strata which might happen to 

 be in the neighbourhood. 



A Swiss geologist of note who shared Buch's views on 

 mountain-upheaval was Bernhardt Studer; he explained the 



