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SUMMARY. 
Although the geological work of the ‘ Discovery ’ Expedition was confined to a 
limited area, the collections of rocks and photographs which have been obtained 
provide materials for forming some definite conclusions as to the geological history 
of the region. The other expeditions, which lately entered the South Polar Regions, 
worked in localities much more than 1000 miles distant from the ‘ Discovery ’ area 
and from each other, and information obtained in one area may not hold for all. 
Chapter 1 deals with most of the islands which occur at intervals along the 
straight north -and-south coast of South Victoria Land, and also with various islands 
lying between New Zealand and Cape Adare and within the Antarctic Circle. They • 
arc bounded by inaccessible cliffs, and the surrounding sea is comparatively shallow. 
Apparently they all consist of recent volcanic rocks. 
Chapter II deals with the islands in the vicinity of Mount Erebus and our 
Winter Quarters. This group I have spoken of as the Ross Archipelago, and of 
the greatest of the group as Ross Island. This island has been built up by the 
volcanoes Erebus and Terror, of which the former is still active ; only steam, never 
any lava or solid matter, was seen to be emitted from the vent at its summit, 
12,000 feet above the sea. 
In Chapter III the relations of the conical volcanoes on the mainland are 
considered. The conical volcanoes lie at the foot of a great wall-like range of 
mountains, which in latitude 78° S. (the Royal Society Range) has a simple tabular 
structure. This range is at least 800 miles long, trends due north -and-south, and 
occasionally rises to peaks 13,000 feet high. On the east it ends abruptly in the 
open Ross Sea, and on the west, for a distance of 200 miles at least, it forms a 
great plateau some 7000 feet above sea-level. 
In Chapters IV, V, VI and VII, the rocks which build up this great range 
are considered in the order in which they occur in the field. 
The gneisses have been found at sea-level and at the base of a series of rocks 
quite f 2,000 feet thick, and may safely be regarded as forming the ancient platform 
on which the central part of South Victoria Land is built. 
The granites belong to two periods, one older and one younger than a certain 
sheet of dolerite. The older granite lies upon the gneissic rocks at the foot of the 
Cathedral Rocks, and dykes from the former ramify into the latter. A peculiarity 
of this mass of granite is that it has a nearly horizontal upper surface which can 
be traced for many miles along the sides of the Ferrar Glacier. 
The Beacon Sandstone Formation is a deposit about 2000 feet thick and 
remarkably uniform in texture. It proved to be quite barren of organic remains 
