359 



Remarks on the Geology of Tavoy.* From a Correspondent. 



An unbroken range of mountains runs parallel with the 

 coast through the whole length of the province, dividing the 

 waters of the Tenasserim from those that fall into the sea and 

 Tavoy river. Its height, east of Tavoy, has been estimated 

 at four thousand feet, but the highest peak which gives rise 

 to the southern branch of the Tenasserim, in about latitude 

 13° 30', rises at least a 1000 feet higher, and is called by the 

 Karens " the Great Mountain." Its naked precipices, as seen 

 at the distance of many miles, seem to promise a fine field of 

 observation for the geologist, but its summit is so precipitous, 

 that the Karens say, the top has never been reached. There 

 is good reason to believe, that this range is principally com- 

 posed of argillaceous slate, or at least slate in some of its 

 forms ; for although in no one place where I have crossed it 

 are the strata exposed on both sides, yet in ascending the 

 western side in about latitude 13° 35', and in descending the 

 eastern side, some thirty or forty miles further north, clay 

 slate of the same variety presents itself on the whole face 

 of the mountain. Adjoining this principal range is some- 

 times seen an interrupted ridge, which occasionally rises high- 

 er than the principal mountains themselves. East of Tavoy, 

 this ridge is composed of gneiss, with a broad dyke of green- 

 stone on its western side. A more irregular chain, consist- 

 ing of a succession of low ranges of from five to fifteen 

 hundred feet high, leaving a wide hilly valley between, runs 

 nearly parallel with the first, broken by numerous gorges, 

 through which the small rivers that rise in the highest range 

 discharge themselves over rapids or falls ; and is the usual 

 boundary of tide waters. This chain, in the latitude of 

 Tavoy, appears to be formed of primitive slate, but after 

 passing the basin of Young-byouk river, thirty or forty miles 

 to the south, the slate strata are left in the interior, and that 



* Plate X. 



