Geological Observations on the Volcanic Islands, Visited During the Voyage of HMS Beagle: Together with Some Brief Notices on the Geology of Australia and the Cape of Good HopeCharles Darwin (1809-1882) published Observations on the Volcanic Islands in 1844. It is one of three major geological works resulting from the voyage of the Beagle, and contains detailed geological descriptions of locations visited by Darwin including the Cape Verde archipelago, Mauritius, Ascension Island, St Helena, the Galápagos, and parts of Australia, New Zealand and South Africa. Chapter 6 discusses the types of lava found on different oceanic islands. There is an appendix of short contributions by two other scholars: descriptions of fossil shells from Cape Verde, St Helena and Tasmania by G. B. Sowerby and of fossil corals from Tasmania by W. Lonsdale. The book is illustrated with woodcuts, maps and sketches of specimens. It provides valuable insights into one of the most important scientific voyages ever made, and the development of Darwin's ideas on geology. |
Contents
CONTENTS | 1 |
CHAPTER II | 23 |
CHAPTER III | 34 |
CHAPTER V | 97 |
CHAPTER VI | 117 |
CHAPTER VII | 130 |
APPENDIX | 153 |
From the Paleozoic formation of Van Diemens Land | 160 |
INDEX | 169 |
Common terms and phrases
abounding albite angular appears Archipelago Ascension augite basaltic basaltic lava basaltic strata beds branches calcareous calcareous matter carbonate of lime cells cellular clay-slate coast colour compact composed concretionary consist containing corals crater crystalline crystals of feldspar crystals of glassy deposit described dikes earthy elevation embedded erupted feet feldspar feldspathic Fenestella fissures Flagstaff Hill formation formed fracture fragments Geological glassy feldspar granite height Helena hollow horizontal hornblende inch inclination injected interior irregular island Jago laminated lava layers limestone mass miles mineral minute mountains nearly numerous observed obsidian olivine origin oxide of iron parallel particles phonolite pitchstone Porto Praya probably Quail Island quartz remarkable resemble ridge round sandstone scoriaceous scoriæ shells side silica similar slightly Sowerby species specimens sphærulites strata streams of lava structure substance summit surface Testá thickness thin trace trachyte tuff upper valley Van Diemen's Land varieties volcanic rocks whilst