As planned by the late Sir Ernest H. Shackleton the voyage of the _Quest_ to Southern Regions was intended to explore the coast from Enderby Land westwards to Coats Land, a length of approximately 2,500 miles. On the routes to and from this main objective it was his intention to call at many seldom-visited islands in the Atlantic, Southern, Indian and Pacific Oceans. A part of the second objective was attained, and the reader who desires to learn of the detailed geological results of the expedition is asked to consult the full scientific report which is now being prepared, and which, by the courtesy of the authorities of the British Museum of Natural History, is to be published as one of their Memoirs. It is the purpose of the writer in these notes to give an outline of the general geology of the islands which were visited. The names given to the rocks are only field terms, as no microscopic examination has been made up to the present. _Methods Employed_ It was found to be seldom possible to do accurate and close geological mapping, owing to the limited time that was available for work ashore. Maps of the areas had to be made, as those of the Admiralty are of too small a scale to do more than provide a skeleton upon which the larger scale sketches can be based. The sketches were generally the result of a rapid reconnaissance with plane table or compass and pace, or in some cases simply a freehand sketch from the summit of a ridge. Wherever possible hand specimens were collected and the general geological associations noted. The order in which the following islands are described is not that in which they were visited, but they are grouped as follows: { South Georgia (68) Islands of the Southern Ocean { Elephant Island (1) { Zavodovski, South Sandwich Gp. (0) { Gough Island (5) { Tristan da Cunha (2½) Islands of the South Atlantic Ocean { Nightingale (1) { Middle (1) { Stoltenhoff (0) { Inaccessible (1) { St. Paul’s Rocks (½) { Saõ Miguel Açores, St. Islands of the Mid-Atlantic { Vincent (Cape Verdes) (3) { Ascension (3) { St. Helena (1) (The numbers in brackets refer to the days spent ashore.) ISLANDS OF THE SOUTHERN OCEAN SOUTH GEORGIA.—_Lat. 54° S. Long. 37° W._ _Topography_