The invention and first use of stratigraphic cross-sections by John Strachey, F.R.S., (1671–1743)

Abstract

Stratigraphic cross-sections, or horizontally extended representations of strata in profile, were introduced into scientific literature in the year 1719 by John Strachey, of Sutton Court, near Stowey Somersetshire, England. Before that time, English-language stratigraphical geology had been practised chiefly by drillers searching for coal, whose published records of vertical sequences of strata and of lateral correlations among subsurface borehole sections, go back to 1639.Strachey's sections were new in several ways: they were drawings rather than lists of strata, they represented true dips, and most importantly they demonstrated stratigraphic correlation in the subsurface and across landscape gaps, where for structural or topographic reasons the intervening strata were obscured or missing.To achieve such delineations in the form of drawings or “draughts”, Strachey assumed as selfevident that the strata were regular in their order of superposition and that they had lateral continuity through concealed areas. His published observations and measurements were widely copied, and William Smith, generally regarded as one of the fathers of geology, seems to have found significant inspiration among Strachey's writings.