XIX.] THE COAL-SEAMS OF LABUAN. 701 



thickness of 3"3, 0'9, 0"4 and 1*0 metre. They dip at an angle 

 of 30° towards the horizon, and are separated from each other by 

 strata of clay and hard sandstone, which together have a thickness 

 of about fifty metres. Above the uppermost coal-seam there are 

 besides very thick strata of black clay-slate, white hard sandstone 

 with bands of clay, loose sandstone, sandstone mixed "with coal, 

 and finally considerable laj^ers of clay-slate and sandstone, which 

 contain fossil marine Crustacea, resembling those of the present 

 time. The strata which lie between or in the immediate 

 neighbourhood of the coal seams do not contain any other fossils 

 than those vegetable remains, which are to be described farther 

 on. Thirty kilometres south of the mine a nearly vertical coal- 

 seam comes to the surface near the harbour, probably belonging 

 to a much older period than that referred to above ; and out in 

 the sea, eighteen kilometres from the shore north of the harbour, 

 petroleum rises from the sea-bottom. The manager of the mine 

 supposed from this that the coal-seams came to the surface again 

 at this place. The coal-seams of Labuan are besides, notwith- 

 standing their jDosition in the middle of an enormous, circular, 

 volcanic chain, remarkably free from faults, which shows that 

 the region, during the immense time which has elapsed since 

 these strata have been deposited, has been protected from 

 earthquakes. Even now, according to Wallace, earthquakes 

 are scarcely known in this part of Borneo. 



From what has been stated above we may conclude that the 

 coal, sand, and clay strata were deposited in a valley-dej^ression 

 occupied by luxuriant marshy grounds, cut off from the sea, in 

 the extensive land which formly occupied considerable spaces 

 of the sea between the Australian Islands and the continent 

 of Asia. A similar state of things must besides have prevailed 

 over a considerable portion of Borneo. On that island there are 

 coal-seams under apj)roximately similar circumstances to those 

 on Labuan. So far as I know, however, they have not hitherto 

 been closely examined with respect to vegetable palaeontology. 



At Labuan fossil plants are found, though very sparingly, 

 imbedded in balls of clay ironstone from strata above the two 

 lowermost coal-seams. The upper coal-seams are besides ex- 

 ceedingly rich in resin, which crosses the coal in large veins. 

 From the thickness and conversion into a hard sandstone of the 

 layers of sand Mng between and above the coal-seams we may 

 conclude that a very long time, probably hundreds of thousands 

 or millions of years have passed since these coal-seams were 

 formed. They also belong to a quite recent period, during which 

 the vegetation in these regions varied perhajDs only to a slight 

 extent from that of the present time. It is, however, too early 

 to express one's self on this subject, before the fossils which we 

 brought home have been examined by Dr. Nathorst. 



