GEOLOGY. The Highlands in the north and west are the remnants of very ancient crystal line and sedimentary rock masses that were greatly disturbed in early geological epochs and have since been largely reduced in height and area by erosion. These regions of ancient rocks were subjected to much faulting and folding; and interspersed among them are areas which vol canic outflows, occurring in various ages and as late as Tertiary times, covered with igneous de posits, that were also greatly disturbed by dy namical energy. These elevated lands are not marked by sharp and jagged peaks, but the moun tains have been worn away into rounded outlines and among them are interspersed a number of broad, plain-like moors broken here and there by more elevated masses of harder and particular ly of eruptive rocks. The Highland regions may be compared in height with our Catskill Plateau and its surmounting elevations.
In sharp contrast with these ancient crystal line, sedimentary, and eruptive masses forming the Highlands are the younger rocks of the Lowlands, the widely distributed Old Red Sand stone of Devonian formation, the chalk and sand stones and the clays of the Carboniferous era.
Toward the south and east of old elevated rock masses are the Carboniferous strata con taining the coal deposits which have con tributed so much to the material greatupss of Great Britain. None of the younger and lower lands has been much affected by faulting and folding. These lower lands extend from the mouth of the Tee to the south of the island, widening with their south extension till they cover the larger part of England, Exeter being their western limit on the south coast. They are mostly flat, trough-shaped, or rolling sur faces of the Triassic, Jurassic, Cretaceous, and Tertiary formations. The greatest diversity of surface and the finest scenery is thus in the north and west, while the lowest and most uniform surface is in the south and east. The extreme south of England escaped glacial action, but else where many of the minor features of the land were produced by the ice sheet and glaciers of the Ice Age. In scarcely any other part of the world is there so wide a range of geological strata in so limited an area as in Great Britain; only the broader aspects of the subjects are here indicated.