~ 
os 
— 
of the river Sekurau (lower course) we find the tertiary formation 
still in the normal Kutei development. 
PMreng Megs! 
SAN FMangBesar Cy 
Le 
In the neighbourbood of the anticlinal axis hard shales and sand- 
stones occur without coal. Then follow — locally separated from these 
by a fault — the normal rocks of the old miocene containing 
glance coal (anthracite) in which, as likewise in the nucleus strata 
of the anticlinal, some limestone banks are found. In the bottom 
half of the mioplioeene we meet with the well-known soft, grey 
clays, sands and inferior coal; on the top of these the above men- 
tioned thick coral limestones lie, and the youngest part of the 
tertiary formation consists chiefly of clay, sand and gravel, in which 
only traces of limestone and coal occur. 
Only a few kilometers to the East, in the Sungei Narut, we find 
an exceedingly thick complex of white and grey coral limestones, 
