SOUTHERN COAST OF PURBECK. 363 



Lulwortb, two little villages near Worbarrow 

 Bay, are the best halting-places for a survey of 

 the south-western shores ; and if the observer be 

 tempted to extend his tour to the Isle of Port- 

 land, Weymouth, of course, will be the place 

 of sojourn. 



As the general dip of the strata is to the north, 

 the lower beds are displayed along the southern 

 coast; and we will now point out the most in- 

 structive localities, in proceeding from the south- 

 eastern corner of the Isle of Purbeck, to the west. 



Contorted Purbeck strata. — The strata in the 

 middle and on the south side of Durlstone Bay, 

 are very remarkable for their broken and con- 

 torted condition, which was evidently produced 

 when the beds were in a plastic state. Septaria, 

 veins of calcareous spar, and crystals of gypsum, 

 occur in some of the clays ; there are also masses 

 of breccia, or conglomerate, composed of fragments 

 of the undulated layers, cemented together into a 

 firm rock.* 



To the west of Durlstone Head, the Portland 

 oolite appears ; and at Tillyichim ilign. 28) there 

 are quarries for the extraction of the fine white 

 limestone, here called Purbeck stone. These strata 



* Mr. Webster has figured a mass of this kind in pi. xxxi. Sir II. Engk- 

 field's Isle of Wight. 



