RESULTS, 173 



"must indeed assume that the geological phenomenon is the same in 

 johar and Tibet as in the instances quoted, but that the scale on which 

 it worked was a very much larger one. This latter assumption is fully 

 justified by the fact that the volume of the fragmental materials as a 

 whole and the size of many of the detached blocks exceeds anything 

 known from the instances alluded to above. 



I am not aware of any occurrence in other parts of the globe 

 which could be directly compared to the one here in question, but the 

 extreme violence sometimes displayed during volcanic outbursts may 

 be illustrated by a few instances. 



As to recent volcanoes the outbursts of G. Pepandajan in Java in 

 1772 may be quoted. According to J. Junghuhn x an area of more 

 than 20 square miles was covered to an average thickness of 50 feet 

 by lava blocks and finer detritus, erupted during a single outburst. 

 Measured from the middle of the crater to the most distant boundaries 

 of the ejected material, this area had a length of more than eight miles. 

 The volume of the erupted masses is said to have been 29,343 million 



cubic feet. 



The volcano of Cotopaxi has been known to throw out, to the dis- 

 tance of eight or nine miles, a mass of rock about one hundred cubic 

 yards in volume. 2 



Attention may further be drawn to a remarkable occurrence in the 

 tertiary basalts of the Isle of Mull, described by Sir Archibald Geikie. 3 

 Near the summit of Sgurr Dearg, bedded basalts enclose " a lenticular 

 band of exceedingly coarse breccia, consisting mainly of angular 

 pieces of quartzite with.fragments of amygdaloidal basalt. In the midst 

 of the breccia lies a huge mass or cake of erupted mica schist, at least 

 100 yards long by 30 yards wide, as measured across the strike up the 



slope of the hill A little higher up, other smaller, but still large blocks 



of similar schist are involved in the basalt. As the huge cake of mica 



> ".lava," 1854, p. 103. 



2 Lyell, Principles of Geol., Ed. 10, vol. II, 1863, p. 223. 



s " On the history of volcanic action during the tertiary period in the British 

 Isles " Transactions Roy. Soc, Edinburgh, vol. XXV, 1890, p. 82. 



( 47 ) 



