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.The Eastern islands are high rocky islands of much 
more recent origin than the Western group. They are 
composed of volcanic rocks — basalt and stratified basal- 
tic tuff (volcanic ash) which has been deposited after 
an eruption. The tuff layers lie in various attitudes, in 
some place due to their position of deposition on the 
sides of the volcanic cone, in others possibly due to 
pushing lip by the extrusion through them of basaltic 
lava. The layers of tuff vary in texture from fine sand 
to coarse agglomerate containing lumps of basaltic glass 
and pieces of fossil eoral up to the size of a football. 
The coral has been altered in the process, but amongst 
specimens I collected. Dr. D. Hill was able to identify 
two species, both of which are still growing to-day on 
the reefs in the vicinity. It seems probable, therefore, 
that the eruption which formed these islands took place 
after the Barrier Reef had begun to form , and they re- 
present Queensland’s most recent volcanoes, though there 
is no record of their activity in historical times. 
The Murray Islands are composed largely of tuff. 
On Mer, which is about a mile and three-quarters long 
and a mile wide, the land rises steeply from close to the 
shore. The highest point is the bill Gelain, 750 feet 
high, at the southern end of the island (Gelam was a 
legendary dugong) . The strata which form this rim of 
tuff everywhere dip outwards towards the shore and 
within the rim is the crater of an extinct volcano, now a 
valley of rich red basaltic soil. To the north-east the 
lava, flow has breached the rim and basalt rocks occur 
down to the shoreline. Danar has two hills with a fer- 
tile saddle between. Waier is almost entirely bare rock 
and is uninhabited. 
Darnley Island is about two and one quarter miles 
long and one and one-quarter miles wide and from ail 
sides it slopes up gradually to a central hill 610 feet 
high. The island is almost entirely composed of basalt, 
but on the northwest shore there is an outcrop of tuff 
and the basalt can be seen overlying it. The sea has 
cut the tuff cliffs back, forming a flat wave platform 
about 15 feet wide, very pleasant to walk along. 
The tuff does not produce very good soil, but the 
red soils from the basalt are exceedingly fertile. On 
both Mer and Darnley the upper slopes of the hills are 
bare of trees and covered with thick, tall kunai grass. 
Trees grow along the watercourses and closer to the 
shore. Apparently Mer at least was originally clothed 
with open forest, but a boat-building industry estab- 
