150 W. H. SucUeston — Creechharrow in PiirbecJ<. 



scarcely necessary to point out tliat the Purbeck Hill (D D), 

 consisting of Chalk, is depressed by perspective, the highest part of 

 it slightly exceeding the height of Creechharrow. A word as to the 

 composition of the Creechharrow Beds seen in this figure may be 

 useful as a sort of recapitulation of what has already been stated. 

 If I give this in the form of a generalized vertical section, it is 

 merely for the sake of convenience, and not to be regarded as 

 absolutely true at any one point. 



1. The highest bed of the series is the deposit on the 

 Creechharrow Limestone. With this must be associated the beds 

 above the 'marl' detailed in the northern section. The thickness 

 of these latter beds is about 13 feet down to the 'main marl,' and 

 they consist of sands, clays, flints, and a thin bed of ' marl.' 



2. The next in downward succession is the hilltop, or Creech- 

 barrow Limestone, which is excessively hard at the summit (A), 

 but becomes softer when traced on the dip slope towards the 

 500 feet contour (the letter C is approximate) ; in this condition it 

 is known as * marl,' and may be about 12 feet thick in some places. 



3. The beds immediately helow the Creechharrow Limestone 

 are extremely variable, and constitute a stratigraphical crux of 

 considerable perplexity. They certainly differ materially within 

 short distances, and but little analogy can be traced between those 

 on the south side of the summit and those on the north side, which 

 are below the 500 feet contour. On the south side of the summit 

 these beds have been traced in detail with considerable accuracy for 

 about 20 feet vertical, and this must be regarded as the standard 

 section. 



On the whole, we may sum up by stating that the bed& 

 immediately below the summit Limestone, for a vertical extent of 

 perhaps 30 feet or more, are sandy, with some yellow clay,, 

 frequently manganiferous, and are characterized by numerous beds of 

 flints, the beds ranging from 6 inches to 3 feet 6 inches in thickness ; 

 loose flints also occur in the sands. 



In further illustration of this class of beds I would direct attention 

 to the eastern spur of Creechharrow (B of Fig. 1). This spur is 

 a conspicuous object from the north-east side, since it breaks the 

 regularity of the conical outline as seen from Furzebrook. 



Being desirous of finding some evidence as to the cause of this 

 slight local prominence, I had a special pit sunk on the very top of 

 it, with the following result : — 



Pit on the eastern spur of Creechbaeeoav. ^j.^ ^^ 



a. Saudy earth with flints 6 



b. FKnt-gravel 3 6 



c. Buff, ferruginous sand with manganese nodules 2 6 



Total section & 6 



The flint-gravel (h) of this section is the thickest deposit of the 

 peculiar ' gravel ' of Tertiary age as yet discovered on Ci'eech- 

 barrow ; water was lying in the bottom of the pit, apparently due to 

 a pan formed by surface action. The extent of the opening scarcely 



