19th May 1835

Coquimbo
I walked a little way up the valley & saw those step-like plains of shingle described by Capt. B. Hall, the origin of which has been discussed by Mr Lyell. The same phenomenon is found in the valley of Guasco in a more evident manner; in places there [are] as many as seven perfectly level & unequally broad plains, ascending by steps on one or both sides the valley. There can be no doubt that during the rise of the land each line of cliff was for a period the beach of a large bay. At Coquimbo marine shells were embedded in strata near the surface; independent of this proof, the explanation of the successive breaking down of the barrier of a lake adduced by Capt. Hall is quite inapplicable. The appearance of these steps, especially in Guasco, is sufficiently remarkable to call the attention of any one who is not at all interested concerning the causes of the present forms of the land. The number of parallel & horizontal lines, of which many have exactly corresponding ones on the opposite side of the valley, is rendered more conspicuous by the irregular outline of the neighbouring mountains.