E. S. Willboum — Tlte Pahang Volcanic Series. 503 



a rough, and cindery appearance. The resemblance between the 

 slag heap of an ironwork and the natural lava is very striking. 

 Indeed, to stand on a lava-flow with the eyes shut by the side of 

 a steam blow-hole and with the smell of the molten metal in the 

 nostrils, it does not require a great exercise of the imagination to 

 transplant oneself from the volcanoes of the South Sea Islands to the 

 ironworks in the Black Country of Great Britain. Travelling over 

 the rugged, cindery flows was attended with difficulty and danger, 

 and the jagged edges made progress slow. 



A strange phenomenon was witnessed in one of the volcanoes. 

 After belching molten metal for two weeks, its activity gradually 

 subsided, and apparently, from out the same vent, torrents of ice- 

 cold water began to flow. The same phenomenon was witnessed by 

 an old French settler in a volcanic outburst twenty years previously. 

 From the other volcanoes abundant streams of moderately cold water 

 gushed out and occasioned no surprise, but ice-cold water and molten 

 metal from the same fountain seemed strange and incongruous. The 

 floods of ice-cold water followed the same course as the lava-flow, 

 covering the lava with a thick layer of silt and ash. A good path 

 was formed, rendering this lava track the easiest of all the streams to 

 traverse. Following its course it is possible to trace the lava from 

 the sea to its place of origin at the edge of the ash plain. 



The phenomena presented by the Ambrym eruptions would seem to 

 indicate that water played as important a part in fissure eruptions, 

 where intermittent explosions of steam were absent, as in the violent 

 eruptions from a crater cone where explosions of steam were present. 

 Eight lava streams were formed during the eruption ; some of them 

 had their source in overflows of lava from crater vents amid 

 paroxysmal explosions of steam, others welled out of the earth like 

 a fountain without the formation of crater cones and without explosions 

 of steam. But the presence of water was as marked in the one case 

 as in the other. In the fissure eruption which took place near the 

 village of Meltungan streams of lava literally gushed out of the 

 fissures without intermittent explosions of steam. These fissures 

 were characterized by an entire absence of volcanic cones and extruded 

 a continuous stream of molten lava which flowed for miles until it 

 reached the sea. The lavas from these flows were impregnated with 

 as much aqueous vapour as the lavas from crater eruptions. From 

 other islands, 15 to 20 miles away, these lava streams could be traced 

 by the columns of steam which rose from the cooling metal. 1 



IV. — The Pahang Volcanic Series. 



By E. S. Willbouen, B.A., Assistant Geologist, Federated Malay States. 



(WITH A MAP, PLATE XXX.) 



(Concluded from the October Number, p. 462.) 



Description of Tuffs and Breccias of the Pahang Volcanic Series. 



BY far the greater part of the volcanic rocks of Malaya consists of 

 fragmental deposits, which at first sight seem to be andesite- 

 tuffs and andesite-breccias, for most of them contain abundant 



1 Dr. Gregory's description of the Ambrym eruptions -will appear in the 

 December Number. 



