For an area so small, England is peculiarly rich in geological interest. This is due in some degree to the energy of the early British geologists, whose work profoundly influenced all subsequent thought in the science, as may be seen by the general acceptation of so many of the English stratigraphical terms; but the natural conditions were such as to call forth and to stimulate this energy in an unusual way. Almost every one of the principal geological formations may be studied in England with comparative ease. If we lay aside for the moment all the minor irregularities, we find, upon examination of a geological map of England, two structural features of outstanding importance. (1) The first is the great anticline of the Pennine Hills which dominates the northern half of England from the Scottish border to Derby. Its central core of Lower Carboniferous rock is broadly displayed towards the north, while southward it contracts; on either side lie the younger rocks, the coal-fields, the Permian strata and the Triassic formations, the last-named, while sweeping round the southern extremity of the Carboniferous axis of the uplift from its eastern and western flanks, spread out in a large sheet over the midland counties. (2) The second striking feature is the regular succession of Jurassic and Cretaceous rocks which crop out in almost unbroken lines from the coast of Dorsetshire, whither they appear to converge, to the Cleveland Hills and the Yorkshire coast. Lying upon the Cretaceous rocks in the S.E. of England are the two Tertiary basins of London and Hampshire, separated by the dissected anticline of the Weald. [Illustration: Map of ENGLAND. Legend: _Recent & Pleistocene_ _Old Red Sandstone & Devonian_ _Tertiary_ _Silurian_ _Cretaceous_ _Ordovician_ _Jurassic_ _Cambrian_ _Trias_ _Metamorphic Group_ _Permian_ _Volcanic Rocks_ _Coal Measures, Carboniferous_ _Basic Intrusive Rocks_ _Millstone Grit Series & Culm_ _Granite & Acid Intrusive Rocks_ _Lower Carboniferous_]