ON THE RUBIES OF BURMA AND ASSOCIATED MINERALS. 
167 
ft. in. 
1. Red homogeneous loam.50 0 
2. Coarse quartz gravel and rubble in which are blocks of partially decom¬ 
posed gneiss and water-worn bluish-black clay slate.10 0 
60 0 
The section seen in a hmyaudwin face, close to Nyoungouk village, 
follows:— 
ft. in. 
1. Red loam.20 0 
2. Yellowish sand and clay, with pebbles.10 0 
3. White quartz gravel, mixed with a small amount of light grey and yellow 
sand, the whole being more or less iron stained. Amongst this are some 
blocks of pegmatite containing black crystals of tourmaline and small 
elongated water-worn blocks of hard dark-coloured clay slate in which 
are thin bands of quartz.10 0 
40 0 
This gravel (No. 3) contains the rubellite and some garnet. 
is as 
3. Sandstone. 
About one quarter of a mile from Thebayetkin the crystalline limestone is covered, 
between that and the Irrawaddy river, by a deposit of grey, friable sandstone, pro¬ 
bably of Tertiary age. The junction of these rocks is obscure. The sandstone beds 
are seen on the back of the Thebayetkin ridge, and in its face on the river bank, 
where a cliff exposes grey, friable sandstone, containing some small quartz pebbles, 
while water-worn blocks of a somewhat similar sandstone form layers in it. These 
beds dip south at an angle of 50°. 
4. Mica Schist. 
About one mile north of Lazee, a village situated on the north bank of the 
Mobaychoung, this rock is met with succeeding the gneissic rocks, which are there 
chiefly represented by pegmatites. The first exposure is of a light greenish colour 
containing a large percentage of silvery mica. This rock is again seen in the bed of 
the Mobaychoung, not far eastward of Lazee, inclining to the south-east at an angle 
of 38°. On the hills at Nayo loose blocks of mica schist are met with. From Nayo 
there is a fine view of the surrounding hill country, which is all deeply covered with 
red loam, presenting a sterile appearance. 
It would appear that the pegmatite passes into mica schist, which probably forms 
a large tract of country to the southward. 
Higher up the Mobaychoung, beyond Nyoungouk, there must be a further change 
in the nature of the rocks, probably from mica schist to clay slate, for waterworn 
