On a Section exposed by the excavation at the New Steam Basin, in Portsmouth Dock-Yard

Abstract

The principal fact which this section exhibits is one with which every geologist is familiar. Almost every writer who has examined any extent of our sea-coasts has alluded to submarine forests, and pointed to them as a proof of the subsidence of the land within a comparatively recent period, and I should hardlyhave thought it worth while to present this section to the Geological Society, if it did not exhibit the facts in a much clearer manner than usually occurs. I may however observe, that I have myself seen the remains of forests, not only along the coasts of England in localities which havebeen described, but also in many places along the coast of Ireland which I believe have not been previously noticed, as in the counties of Wicklow, Wexford and Waterford, and at BalaCOtten, Kinsale and stletown-bearhaven, in the county of Cork.These observations indicate that the subsidence in these islands was general as regards the southern portion of their areas*. The substratum of the section described is the upper portion of the London clay (1) ; which is here very fossiliferous and dips to the north, or towards the chalk ridge at Hilsea. This however is merely an undulation of the strata, as all the lower beds are brought up in succession before we arrive at the chalk, and the red plastic clay from Stamshaw, about a mile to the north, is used for making the dams water-tight, a purpose for which, from its weight and tenacity, it is