582 BR. H. HICKS ON SOME RECENTLY-EXPOSED SECTIONS 



the depOoits also have heen far more completely made out in the 

 more recent exposures referred to in this paper. 



In the patch directly north of the Hendon plateau, upon which 

 no pits are indicated, so few exposures have been made that the 

 boundaries of the Glacial Drift can only be approximately given, 

 and the evidence of its character has been derived mainly from 

 shallow drains at various points, and from the railway-cutting and 

 some deep wells in Page Street, just beyond the limit of the Map 

 accompanying the present paper (PI. XXII.). What has been 

 exposed in the shallow drains was mainly a yellowish -brown clay 

 containing many flint-pebbles, but some gravel was met with in the 

 railway-cutting, and it must also be present where the wells have 

 been sunk. I'hat at the Tithe Farm is stated to be about 20 feet 

 deep. 



In the two other patches along the W. side of the Prent Valley 

 the deposits have been exposed in gravel-pits and deep w^^lls and 

 in excavations for the main sewer. At Holder's Hill the Boulder- 

 clay was found to attain to a considerable thickness, and it resembled 

 that found on the Hendon plateau. The area on the Pinchley side 

 of the Brent (indicated as covered Avith Glacial deposits) contains 

 in places the typical Chalky Boulder-clay, but at most points along 

 the sides of the Brent Yalley a thick coating of brown clay overlies 

 the sands and gravels. In the patches at Temple Fortune and 

 Golder's Green the clay is also mainly of a brown or yellowish-brown 

 colour, and no typical Chalky Clay has hitherto been discovered 

 there. Sands and gravels were exposed at several points in the 

 sewer excavations in these areas, and much sand and gravel was 

 obtained some years ago in a field on the south side of Bridge Lane, 

 between the Decoy Farm and Temple Fortune. The Golder's 

 Green patch might well be extended to the west side of Hamp- 

 stead Hill, for Glacial deposits have been exposed at several points 

 between the Brent Yalley and the slope of that hill. 



IV. Conclusions. 



There can now be no doubt that Glacial deposits similar to 

 those found at Finchley and Whetstone on the jST.E. were spread 

 out in a S.W. direction across the Brent Valley and over the 

 Hendon plateau, reaching downwards on the slopes to below the 

 Ordnance datum-line of 200 feet. There is good evidence also to 

 sliow that they passed across the valley separating Hendon from 

 Kingsbury, and that they now occur on most of the heights in the 

 latter parish. Thej are also found at Dollis Hill, and at some other 

 points in the parish of Willesden. It is certain, therefore, that the 

 physical features of this part of N.W. Middlesex were moulded at 

 a very early stage in the Glacial period, or clearly previous to the 

 deposition of the so-called Middle Sands and Gravels, and of the 

 Upper or Chalky Boulder- cla)\ At this time there could have been 

 no barrier of any importance to prevent these deposits from extend- 

 ing into the Thames Valley, and the evidence clearly points to the 

 conclusion that the implement-bearing deposits on the higher 

 borizons in the Thames Valley should be classed as of contempo- 



