480 R. D. Verbeek — Geology of Sumatra. 



seams, but these are of considerable thickness. The section of this 

 series in the neighbourhood of the village of Soengei-Doerian, from 

 bottom to top, is.: — 



Thickness in Metres. 

 Sandstones and clays ... 50 (more or less) . 



First (lowest) coal-seam 



Sandstones and clays ... .... 



Second (middle) coal- seam ... 



Carbonaceous shale, with fossil remains 



Sandstones and clays 



Third (upper) coal-seam 



Sandstones and conglomerates 



6 



20 



2 



i 

 a 

 15 

 2 



250 (more or less). 



Total thickness of the series 350 (more or less). 



Total of coal 10 

 The coal from the Oembilien coal-field is the best in the Netherland 

 Colonies ; and indeed, although of Tertiary age, is among the very- 

 best coals known. The composition, .according to the analysis by 

 Dr. Vlaanderen, at Batavia, is : — 



C= 76-80 



H= 5-80 



0+(N) = 12-76 



S= 0-45 



H,0= 3-49 



Ash= 0-70 



100-00 



The theoretical evaporating power, according to this composition, 

 A=7500. 



It is a black, shining, lustrous, and compact coal. As the Soengei- 

 Doerian seams are very regular, they are under very favourable 

 circumstances for working. 



The clays are found immediately beneath the coal-seams. The 

 second (middle) coal-seam is covered by a carbonaceous shale, half a 

 metre thick, which is remarkable for its fossil remains, — spines and 

 teeth of Fishes. The sandstones contain no fossils ; the coal and the 

 clays only a very small number of fossil Plants. 



5 c. In the marl-sandstone series, although of considerable thick- 

 ness, there are only found some small Operculince and little Fish-teeth, 

 in the neighbourhood of the village of Moara-Bodi, and some frag- 

 ments of Shells, belonging to Ostrea, Pecten, etc., which prove that the 

 marl-sandstone is a salt-water deposit. 



5 d. The upper part of the Tertiary deposits, which are known in 

 the Sumatran Highlands, is a limestone offering a great variety of fos- 

 sils, — Corals, Echinids, Gasteropods, and Conchifers, mostly as casts, 

 and a great many specimens of an Orbitoides. 



These four groups of strata generally succeed one another conform- 

 ably, but in some localities there is a fault between 5b and 5c. The 

 lower series, 5a and 5b, rest unconformably on the Limestone with 

 Fusidinoe. 



The preliminary determination of some fossils from these beds, for 

 which I am very much indebted to Prof. T. Eupert Jones, York- 

 town, Surrey ; Prof. H. B. Geinitz, Dresden ; and Prof. O. Heer, 





