ANDREWS: LIMESTONES OF THE FIJI ISLANDS. 13 
General Geological Structure. 
Tue Larcer ISLANDs. 
Viti Levu.1 — In this, the largest island in the Fiji Group, my researches 
were confined to an examination of the Suva district, of a ten-mile strip 
stretching from Nandronga Singatokawards, and a short excursion ex- 
tending over some thirty miles up the large Singatoka River. Viti Levu 
and Vanua Levu stand out distinctly from all other members of the 
group, and bear the imprint of a hoary antiquity compared with the 
volcanic islands of Taviuni, Ngau, and Kandavu, as well as with 
the limestone islands constituting the Lau division of the Fiji area. Pro- 
ceeding along the banks of the Singatoka River, interesting outcrops of 
limestone of high dip were observed. Volcanic agglomerates of porphy- 
rite and masses of andesite rock, apparently identical with similar rocks 
in the younger islands, have burst through the more ancient sedimentary 
rocks. The volcanic rocks exhibit various stages of decomposition. The 
hills roll, cone after cone, behind each other to a height of 3000 feet, and 
the main road follows the curves of the lower hill shoulders, thus reveal- 
ing numerous dykes, and thin beds of strata, dipping at high angle, which 
are crossed again and again in a few hours’ walk, In places these strata 
contain a bright green cherty rock, interbedded with softer brownish 
layers. 
The Stratified Rocks. — Argillaceous rocks and soft crumbling beds 
occur with high dip. They are brown in color and at times effervesce 
with acid. 
The Dolomites. — These appear to underlie the strata just enumerated. 
They are principally centred in an immense block overlooking the river. 
They consist of two hills 1000 and 1500 feet respectively above the 
river, and reaching, in the case of the smaller one, into the water at the 
base. They are practically perpendicular, having a slope of 85° in places 
and 90° in others, and are uniformly hard and homogeneous in character 
from base to summit. They are tunnelled with caverns. To the eye or 
ordinary lens they are non-fossiliferous. Acid scarcely causes any effer- 
vescence. According to report this rock is found along a line roughly 
northwest and southeast, but I saw no trace of its development else- 
where. 
Of the evidently later limestones that more or less fringe the shore of 
the island near the mouth of the Singateka River, one notices, com- 
1 See A. Agassiz, Bull. Mus. Comp. Zodl., 1899, Vol. XXXIII. p. 110. 
