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PRELIMINARY REPORT. i, 
the so-called soapstone of Fiji. I was informed that other islands in 
this group, near Tonumeia, in the centre of the Nomuka plateau, were 
volcanic. Mango, as we could see it from our anchorage, appeared to 
be voleanic. So that this part of the Tongas is, like the Lau Group 
in Fiji, made up of islands in part volcanic and in part composed of 
elevated coralliferous limestone. The eastern edge of the Nomuka 
plateau (which we did not visit) is edged with small low islands. We 
merely steamed by the western islands of the Haapai Group, but close 
enough to see that Tongua, Kotu, and Fotuhaa, which vary in height 
from 120 to 200 feet, are composed of elevated limestone. The eastern 
flank of the Haapai plateau is edged with long, low islands, with exten- 
sive coral reefs along the reef flats of these islands. 
The Haapai plateau is triangular, with isolated islands rising on the 
northwestern side from the deep water separating it from the Vavau 
plateau. It is separated from the Nomuka plateau by a narrow channel 
with over 300 fathoms of water. 
The northernmost plateau of the broad ridge of the Tonga Islands is 
the Vavau plateau. This is elliptical, with a long tongue extending on 
the eastern face of the ridge toward the northern point of the Haapai 
plateau, ending in isolated banks (the Disney reef and Falcon bank), 
lying to the northward of the broad channel, with over 400 fathoms 
separating it from the Haapai Group. The Vavau Group is by far the 
most picturesque of the Tonga Islands. It consists of the principal 
island of Vavau, extending across the northern part of the Vavau 
plateau. Several parts of the island of Vavau, as at the southwestern 
extremity, at the entrance to the harbor of Neiafu, and at Neiafu, are 
finely terraced; four terraces are indicated there, and other flat-topped 
smaller islands show traces of two or three terraces. The northern edge 
of Vavau Island rises to a height of more than 500 feet, and slopes in 
a general way southward and inland.. The southern shore is deeply 
indented by bays and sounds, and flanked by innumerable islands and 
islets, some of considerable height (150 to 250 feet) which gradually 
become smaller and smaller as they rise toward the southward and east- 
ward, these islands having been formed from the denudation and erosion 
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