23rd September 1834

Valparaiso
I staid here the whole ensuing day, & although very unwell managed to collect many marine remains from beds of the tertiary formation of which these plains consist.

The presence there of beds of early Tertiary rocks 800 feet thick containing fossil shells that could only have lived in shallow water provided useful proof for Darwin's theory that at such places there must have been a slow subsidence of the sea-bottom in a previous era.

No comments: