A HISTORY OF SURREY 



shower of calcareous organic particles descended upon the sea floor ; and 

 the duration of this shower was so long that the great Chalk forma- 

 tion was built up by it. Then we found a wide gap in the records; 

 and when we crossed this gap to the Eocene strata, we learnt once 

 more of a shallow sea, inhabited by animals all different from those of 

 the older time, and this sea had already made great inroads upon the 

 consolidated sediment of the preceding period ; the climate was warm, 

 perhaps sub-tropical, and not far off there was a land clothed with 

 rich vegetation ; and as the sea grew shallower the estuary of a large 

 river invaded our tract, but was soon driven back by a renewed sinking 

 of the land. Then, as the Eocene Period drew to its close, we observed 

 how re-elevation set in, with the renewal of shallow-water conditions ; 

 and with this stage the building up of our county was concluded. 



Regarding subsequent events our evidence has been scanty, but we 

 have been able to gather that the strata were disturbed and uplifted 

 into dry land ; and that owing to inequalities of the uplift this land sloped 

 to the north, so that the rivers which flowed from it took a northerly 

 course, which they have since maintained. And we have traced the 

 work of these rivers and their tributaries through a period of gradually 

 increasing cold, until conditions of arctic severity ruled in the land ; and 

 finally through a period of gradual amelioration, which has continued up 

 to time recent ; and meanwhile great piles of strata have melted away, 

 and the remnants have been carved into hill and dale under the persistent 

 sapping of the agencies of erosion. 



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