III.—Notes on a Collection of Rocks from the Tonga Islands

Abstract

The Tonga or Friendly Islands in the South Pacific Ocean seem to have received hitherto no attention from geologists, and I can find no published information as to their geological constitution beyond the simple record of the existence of volcanoes and coral-reefs. The material of these brief notes was mostly collected by Mr. J. J. Lister, M.A., during the cruise of H.M.S. Egeria in 1889; and, through the courtesy of Captain Wharton, R.N., F.R.S., Hydrographer to the Admiralty, I have had the opportunity of examining a few additional specimens collected by Captain C. F. Oldham, R.N., Commander of the Egeria, in 1890. In view of the general account of the islands which Mr. Lister is preparing, I notice here only such points as arise directly from an examination of the specimens.