2IO M. H. LOVEMAN 



Coggin Brown in discussing the Kao-liang system states that 

 "lower down the eastern slope of the divide (Irrawady-Salween), 

 silver-grey phyllites are interbedded with dark slates and bands of 

 limestone. In the latter occurrence there is a marked difference 

 from the Chaung Magyi system of the Northern Shan States, which 

 otherwise they greatly resemble, for the former system does not 

 contain lime in any form." On the assumption that the Pangyun 

 beds are a transition series between the Chaung Magyi and the 

 younger fossihferous beds it is possible that the beds observed by 

 Coggin Brown belong to this series and thus represent the passage 

 from the Kao-liang system to the Pu-Piao series. 



The younger Ordovician and the Silurian beds closely resemble 

 those described by La Touche for the area to the south. They 

 consist of sandstones, shales, marls, and occasional limestone 

 beds. A detailed study of these beds in this section, with careful 

 paleontological work, would undoubtedly allow of their being 

 separated into their smaller subdivisions, as has been done by La 

 Touche for the rest of the area. 



The Pu-Piao series and the Silurian system in Yunnan of 

 Coggin Brown are assumed as being analogous with the group of 

 beds mapped here as lying between the Chaung Magyi and the 

 younger limestones, with the slight difference that the bottom 

 member (Pangyun beds) may belong both to the Kao-liang and the 

 Pu-Piao. 



DEVONIAN-CARBONIFEROUS-PERMIAN (pLATEAU LIMESTONe) 



It has not been attempted to differentiate this formation, which 

 covers a period from the Devonian to the Permian, into an upper 

 and lower, as has been done by La Touche in the southern area. 

 It is a direct continuation of the Plateau limestone mapped by him, 

 and similar to it in all respects. In all the eastern section of the 

 area it completely covers the older rocks except at two points, one 

 in the northeast corner, where an eroded anticlinal mass has exposed 

 the older sediments down to the Chaung Magyi, and the second 

 in the gorge of the Salween, which river has cut its way down 

 through the limestone and Silurian and Ordovician sediments into 

 the Cambrian. At neither of these points are igneous or meta- 

 m Orphic rocks exposed. 



