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 . 



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