24 PKOCEEDINGS OF THE GEOXOGICAL SOCIETY. [NoV. 9, 



country in those directions only where the inlets opened to the sea 

 (the gravel within the inlets remaining comparatively undisturbed), 

 the Hampshire high-brow gravels are everywhere so cut oiF in the di- 

 rection of the chalk country — as they would be, supposing them, as 

 I do, to be a remnant of the open sea-bottom of the period. All the 

 numerous sections given by Mr. Codrington present this feature ; 

 and though they omit the delineation of the older Tertiaries upon 

 which the gravels rest, an examination of the distribution of these 

 tertiaries as delineated in the Hampshire maps of the Geological 

 Survey will show, by comparison with the sections of Mr. Codrington, 

 that the gravels here have partaken, along with the tertiaries upon 

 which they rest, of that denudation which was consequent upon the 

 upcast of the chalk country. Mr. Codrington regards these gravels 

 as the deposit of an estuary of the sea, some twenty miles wide, that 

 was bounded by the chalk country to the north as land ; and so I 

 agree they were, but not at that early stage when the gravel cap- 

 ping the brows of elevation (to altitudes of 400 feet and upwards) 

 rose out of the sea. At that time the gravel of the Hampshire high 

 brows stretched, I conceive, across the chalk country into connexion 

 with those gravels of the Thames, East-Essex, and Canterbury sheets 

 which now occupy similar brows of denudation, the conditions of land 

 and water being those represented in Map No. II., save that there 

 may have been many islands of chalk over Hampshire that I have 

 not ventured to repi'esent. The marine denudation, consequent 

 upon the upcast of the chalk country, swept off this continuous 

 gravel sea-bottom from the parts subjected to the principal elevatory 

 movements, and cut back the older tertiary outcrops, with their 

 gravel covering, into the condition of brows just discussed, such 

 brows being lifted above the sea. To the south, towards the South- 

 ampton water, the but little disturbed sea-bottom continued to receive 

 and preserve gravel accumulations, which formed a more or less con- 

 tinuous sheet with the gravel which had become land on the brow- 

 tops ; while to the north, in the Thames valley, the waters, now con- 

 verted into the fluviatile condition, continued to deposit gravel and 

 brickearth, which inosculated with those portions of the earlier or 

 marine deposits that had remained undisturbed, but formed terraces 

 beneath the earlier-deposited gravel where this had been elevated*. 

 I here reproduce a reduction of section 10 of my paper in the 

 23rd volume of the Society's Journal f, placing beside it one taken 

 from Mr. Codrington's section 6, but extended so as to reach the chalk 

 country, and having the older Tertiaries inserted in it — in order that 

 the identical features which the gravel brows of either area present 



* These marked terraces, where they exist in the Thames area, are shown in 

 Map No. I., and the lower terrace deposit indicated by a different set of dots 

 and lines from the main-sheet gravel. Where no such marked terrace exists, 

 the older and newer portions of the Thames gravel are shown necessarily under 

 the same kind of dotting. 



t In the original section the denuded shelf separating, along the line of section, 

 the gravel on the brow from that at lower level (with which, however, it inoscu- 

 lates in other directions) was not shown ; but it is corrected in the present section. 



