Narrative of the surveying voyages of His Majesty's Ships Adventure and Beagle, Vol. 3 [of 3] · Charles Darwin
NORTHERN CHILE AND PERU.
On the mainland in front of San Lorenzo, near Bellavista, there is an extensive and level plain, at the height of about a hundred feet. The section on the coast shows that the lower part consists of alternating layers of sand and impure clay, together with some gravel; and the surface, to the depth of from three to six feet, of a reddish loam, containing a few scattered sea-shells, and numerous small fragments of coarse red earthenware. At first I was inclined to believe that this superficial bed must have been deposited beneath the sea; but I afterwards found in one spot, that it covered an artificial floor of round stones. The conclusion which then seemed most probable was, that at a period when the land stood at a less height, there was a plain very similar to the one now surrounding Callao, which being protected by a shingle beach, is raised but very little above the level of the sea. On this plain, with its clay beds, I imagine the Indians manufactured their earthen vessels; and that, during some violent earthquake, the sea broke over the beach and converted the plain into a temporary lake, as happened in 1713[14] around Callao. The water would then deposit mud, containing fragments of pottery from the kilns, and shells from the sea. This bed with fossil earthenware occurring at about the same altitude with the terrace on San Lorenzo, confirms the supposed amount of elevation within the human period.
Ideas discussed in this chapter
Text from Project Gutenberg, public domain in the United States.