John StracheyBorn 10 May 1671; died 11 Jun 1743 at age 72.English geologist who was the first to suggest the theory of stratified rock formations. He wrote Observations on the Different Strata of Earths and Minerals (1727) and stated that there was a relation between surface features and the rock structure, an idea that was not commonly accepted until a century later. He studied the stratigraphy of coal mines, and published two geological papers on the subject in the Philosophical Transactions. In them he sketched cross-sections of strata, using fossils to identify one stratum. His 1725 paper contained the first clear indication of an angular unconformity, the importance of which was not realised until much later. He mapped Somerset, showing among other things the sites of coal and metalliferous mines. |
