GEOLOGY wooded tract known as The Blean, extending along the seacoast from Whitstable to a little beyond Heme Bay and inland nearly up to the valley of the Stour, but is frequently covered with patches of Pleistocene gravel, brickearth and loam. Though rich in fossils, these are unequally distributed, being very numerous in some localities and rare or absent in others. They are essentially marine, but include many remains drifted from the land ; and it is probable that the river of which we had glimpses in the earlier Eocene deposits still continued to pour its burden of land-waste into the sea in this quarter, though its actual estuary now lay at some distance from our district. Hence besides very numerous species of marine fish, molluscs, crustaceans, annelids, echinoderms, corals, etc., the fossils include, in less abundance, the relics of extinct mammals, birds, turtles and crocodiles,^ along with many plant-remains, chiefly the seeds and fruits which are preserved in a pyritized state. The most prolific locality for these fossils, especially for the plants and vertebrate animals, is the coast of Sheppey, as above mentioned. The climate of the period, as indicated by these fossils, must have been considerably warmer than at present ; and indeed throughout Early Tertiary times the conditions appear to have been such as now only prevail much farther south in our hemi- sphere. Lower Bagshot Beds. — Of the events which succeeded the deposition of the London Clay our evidence is meagre and all in shreds and patches. Deposits preserved in Surrey and the country farther to the westward indicate that there followed a gradual change, owing to the re-elevation of the sea floor, so that shallow-water and estuarine conditions once more prevailed in this part of England, whereby sands and pebble beds were spread out over the London Clay. But in Kent, where they may once have existed, these newer Eocene beds have been denuded away, except in the Isle of Sheppey where in a few places the uppermost portion of the London Clay passes upward into sand and loam with clayey partings, supposed to represent the lowest part of the Lower Bagshot Beds of Surrey. The largest of these outliers occurs between Minster and Eastchurch ; it is barely a square mile in extent. THE MIOCENE ELEVATION Then follows a long blank in the stratigraphical succession, the remainder of the Eocene and the whole of the Oligocene and Miocene periods having no representatives in our county. Indeed, in no part of England is there any deposit of Miocene age, and the Oligocene is represented only in the ' Hampshire basin,' where there are alterna- tions of marine, estuarine and freshwater strata of this age. We know however that during this long interval great changes in the distribution of land and sea took place throughout Europe, owing to powerful move- 1 For particulars respecting the vertebrate fauna of the London Clay, see subsequent article ' Palaeontology,' p. 3 1 . 19
