382 



THE WONDERS OF GEOLOGY. 



Lect. IV. 



Handfast Point. The lower divisions of the chalk dipping 

 at a considerable angle to the north, next appear ; and are 

 followed by the Wealden clays, sands, &c. which stretch 

 along Swanage Bay, to the elevated 

 ridge of Purbeck strata, on the south 

 of the little town of Swanage. At 

 2 -I Durlstone Head a fine section of the 

 ' a ° Purbeck beds is exposed ; and at the 

 | | extreme point, the Portland oolitic 

 « | limestone appears. Purbeck has long 

 | co been celebrated for its quarries, which 

 g « have been worked from time imme- 

 , g | morial, and particularly during the 

 p | middle ages ; the compact varieties of 



* J f the limestone, which take a good po- 

 S § . lish, having, under the name of Pur- 

 's | beck marble, been in great request for 

 § « 2 tne religious edifices of that period ; 



* | I and there is scarcely a cathedral or 

 £ 3 ^ ancient church in England that does 

 S| ^ not contain columns, sepulchral monu- 

 % 5 g ments, or pavements, of this material. 

 §* 8 This marble (Lign. 96) is a congeries 



1 ° of small river snail shells, intermixed 

 < with the crustaceous cases of minute 



2 o cyprides. 



g « 14. Coves in the south-west of 

 7 g the Isle of Purbeck. — Onthesouth- 



* | west coast of the Isle of Purbeck, the 

 £ S range of vertical chalk strata, the 



| | ~ eastern extremity of which forms the 



| g high cliffs at Handfast Point (Lign. 



81), reappears in several coves or 



inland recesses, which have been formed by the inroads of 



the sea ; no less than nine sections of the strata, from the 



