Signal Post Hill and Agua de la Zorra: two geological sites studied by Charles Darwin on the Beagle voyage and their contributions to geoheritage

Abstract

Abstract Charles Darwin's research during the second voyage of HMS Beagle is examined within the context of Charles Lyell's ideas on crustal movement. Darwin's pre-voyage training is summarized and the impact on his own subsequent theorizing of his commitment early in the voyage to a Lyellian theoretical framework is analysed. Two sites studied by Darwin which he interpreted as strong support for Lyell's theory of vertical crustal mobility are examined: the first is Signal Post Hill in the Cape Verdes, visited in 1832; the second is Agua de la Zorra in Argentina, visited in 1835. Darwin's work at both sites was key to his first theory of globally-balanced elevation and subsidence as an explanation for the structure and distribution of coral reefs. The case is made that both sites are of international geoheritage importance and that their protection should be assured with enhanced access and interpretation.