This work presents a detailed examination of the geological features of South America, based on observations made during the voyage of the Beagle. It covers the elevation of both the eastern and western coasts, the characteristics of the plains and valleys of Chile, and the formations of the Pampas. The text discusses older tertiary formations in Patagonia and Chile, as well as plutonic and metamorphic rocks, including their cleavage and foliation. The structure of the Cordillera is analyzed, and the author concludes with insights on the geological history and processes that have shaped the continent, providing a foundational understanding of physical geology and physiography.