1869-1919

American geologist best known for his work on the strength of Earth's crust. He argued Earth's rigid outer crust rests on a semi-plastic layer, proposing the names lithosphere for the former and aesthenosphere for the latter. Barrell also developed a revolutionary interpretation of sedimentary strata. Prior to his work all sediments were believed to be produced by the oceans. Barrell showed that at least one fifth of all land surfaces are composed of other sediments.