356 LA TOUCHE : GEOLOGY OF NORTHERN .SHAN STATES. 



been found in the limestone bands interbedded with the Namyau 

 sandstones. 



The geological history of the Shan States, so far as deposition 

 Perm uient c 'cn under marine conditions is concerned, ends 



with the accumulation of these red beds. In 

 common with the whole of China as yet explored, no rocks of 

 Cretaceous age have been met with, 1 and the subsequent history 

 is one of elevation above the sea level and degradation. The 

 nearest examples of deposition at this period are to be found 

 in the Arakan Yoma and along the southern flanks of the Assam 

 Range, where the work of filling up the Burman and Himalayan 

 ' foredeeps ' was actively in progress ; and where beds of this age 

 are followed by the Nummulitic limestones and higher Tertiary 

 strata of Assam, the Irrawaddy valley, and the Chin-Lushai ranges. 

 But no trace of any of them has been found to the east of the 

 scrap of the Shan plateau. 



At what precise period the elevatory forces manifested their 

 P riod of emer<* nee greatest degree of activity, that is to say, 



when the extreme folding and crushing of the 

 rocks took place, is somewhat uncertain. It seems to have been 

 either anterior to that of the Himalaya, or to have proceeded for a 

 time more rapidly, for strata of nummulitic age are known to occur 

 on some of the higher peaks of the latter range, 2 and Suess remarks 3 

 that the Burmese arc of folding preceded that of the Himalaya. But 

 for the most part these great thrust movements, the one acting from 

 the north and the other from the east, must have proceeded simul- 

 taneously, and there is a considerable analogy between the final 



results attained in each case, though they are 

 ^^»arison between 0 f ver y different orders of magnitude. On 

 mese arcs of folding. the Burmese side we have the Shan plateau 



corresponding, but at a much lower elevation, 

 with the Tibetan plateau, both of them the elevated floor of 

 an ancient ocean, now undergoing abrasion and reduction to 

 a peneplain. The outer edge of each plateau is bounded by what 

 is virtually a scarp ; and though it may seem almost absurd to 

 compare the mighty chains of the Himalaya with the insignificant 

 fringe of Archaean and Palaeozoic rocks that borders the Shan 



1 Bailey Willis, Research in China, Vol. II, Chap. VI, p. 95. 



2 T. D. La Touche, Re-discovcry of Nummulites in Zanskar ; Records, Gecl. Surv. 

 Ind., Vol. XXI, Pt. 4, p. 100. 



3 Das Antlitz der Erde, Vol. Ill, Pt. 2, p. 579. 



