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WONDERS OF GEOLOGY. Vol. I. 



well and Christchurch, formed of freshwater and marine tertiary deposits ; and 

 entering Studland Bay, perceive the vertical chalk cliffs of Handfast point. Coast- 

 ing along the Isle of Purbeck, the different members of the cretaceous and wealden 

 formations are seen in various parts of this sinuous and indented line of coast ; in 

 some places forming the entire cliffs ; in others surmounting the Kimmeridge clay 

 and Portland oolite ; and we pass by the little Coves in the south-west of the Island, 

 in which the strata of the Chalk, Wealden, and Oolite, appear in a vertical 

 position.* 



Rounding the insulated mass of Oolite that forms the Isle of Portland, we reach 

 the Dorsetshire coast, which is here composed of beds of the Inferior oolite. These 

 deposits are succeeded near Lyme Regis by cliffs of Lias ; which the researches of 

 the late Miss Mary Anning, and Mr. Hawkins, have rendered so celebrated; the 

 remains of Ichthyosauri, Plesiosauri, and other reptiles, with numerous shells, 

 crinoidea, and plants, excelling in beauty and variety, those of any other English 

 locality. 



The Lias is succeeded on the west by Triassic strata; and these, after a short 

 interruption of greensand, reappear and continue by Sidmouth, Exmouth and 

 Teignmouth to near Babbicombe, where the Devonian, or Old Red deposits, first 

 emerge: beautiful coralline marbles are quarried near Babbicombe. 



The coasts of Devonshire and Cornwall, with but few interruptions, are made up 

 of the different members of the Devonian system ; Silurian strata occurring in a few 

 localities. Mica and Chlorite schists, form the promontory at Start Point; Serpen- 

 tine and Biallage rock; the Lizard ; and Granite, the Land's-End. From Plymouth 

 to Falmouth is the grand region of copper ores ; the country consisting of slaty rocks 

 (termed Killas), and limestones, traversed by porphyritic (provincially called 

 Elvan) dikes, with protrusions of granitic rocks. Intrusions of Trap are frequent all 

 over this part of England ; at St. Ives, the cliffs are composed of this igneous 

 product. 



The western shores of Cornwall present similar phenomena; and throughout this 

 sea-coast, elevated terraces of beach or shingle are numerous, proving the frequent 

 alteration in the relative level of sea and land, which have here taken place. 



Along the west coast of Devonshire, beds of the Carboniferous system appear; 

 the shales are often highly contorted, and occur in the state of indurated slate, pro- 

 vincially called culm: they contain shells, and many of the usual species of coal 

 plants. 



In north Devonshire, the Devonian system reappears ; and at Ilfracombe there are 

 beds of limestone and calcareous slates, full of shells and corals. If we pass up 

 the Bristol Channel, as far as Watchet, we find a line of Lias cliffs, abounding in 

 shells and reptilian remains. 



But it would extend this notice to too great a length, were I to point out every 

 interesting locality within view, in our voyage along the western coasts of Eng- 

 land: it must, therefore, suffice to mention only the most striking geological 

 phenomena. 



Crossing to the opposite Welsh coast, mountain limestone, capped by Lias, appears 

 at Nash Point, and near Dunraven ; and in Swansea and Carmarthen bays, we 

 perceive the great South-Wales coal-measures fully developed ; the promontory of 

 Worm's Head, which lies between the bays, being composed of Devonian strata 

 and Mountain limestone. Near Tenby, the cliffs are fonned of carboniferous 

 deposits, very much contorted: and beyond, at St. Coven's Head, beds of mountain 



* The details of the geology of the coasts of the Isle of Wight and Purbeck, are 

 given in my Geology of the Isle of Wight. 



