J. A. Birds — Oeology of the Channel Islands. 83 



The shores of Sark are generally more or less inaccessible ; and tlie 

 only way to explore the island properly would be from a boat. 



Of Jersey Prof. Ansted lias given the following section, wliich I 

 take the liberty of copying from his and Dr. Latham's work.^ 



Geological section across Jersey from East to "West. 



West 



Length of section 11 miles. 



a. Firm syenite, b. Rotten syenite, c. Quartzite. d. Indurated shale, e. Shale. 

 /. Hornstone schist, g. Old conglomerate, h. Newer conglomerate, i. Sand- 

 stone, k. Eaised beach. L Pebble beach, m. Blown sand. 



The syenite, indeed, forms the basis of all the other rocks. It does 

 not, however, as might be supposed from the section, protrude at 

 three distinct points, the intermediate spaces being covered with 

 shale, but rather appears as three separate masses, in the north-west, 

 south-west, and south-east of the island. The first and largest of 

 these may be followed continuously along the coast from L'Etac, 

 round by Grosnez and Plemont Points to Point Sorel, and the 

 quarries north of St. John's Church ; it is traceable inland by the 

 quarries of Mont Mado, and a little south of the Wesleyan Chapel 

 called Les Freres, to the head of St. Mary's Valley, near the fifth 

 milestone, and thence almost in a direct line to L'Etac. The second 

 mass occupies nearly the whole of the parish of St. Brelade, and 

 forms the coast-line from La Carriere opposite La Rocca Tower, in 

 St. Ouen's Bay, to the Corbieres rocks ; and thence to a point a 

 little below Noirmont Manor House. The boundary of this mass 

 inland is generally covered on the west by blown sand, but it 

 appears again between Tabor Chapel and St. Aubin's in the shape of 

 a granital of quartz and felspar, very subject to decomposition, in 

 which state it forms a fine china-clay. Quarries have been opened 

 here, and the clay is exported to England. From this point the 

 boundary may be traced S.E. to the shore again under Noirmont 

 Manor. The third and last mass of the syenite forms the S.E. 

 corner of the island, and may be followed along the coast from Fort 

 Eegent at St. Helier's to La Eocque Point. It is interrupted at two 

 points, viz. at La Collette under Fort Regent, and in the headland 

 of Samares, by veins of hornblendic granital. Between La Eocque 

 Point and Mont Orgueil Castle the rocks are covered by the sands 

 of Grouville Bay ; but the syenite, which here passes into a granital 

 (quartz and felspar), may be traced inland by Gorey Church, and 



' The Channel Islands, p. 270. Geological maps of the islands there are none 

 at least I have seen none, except the sketch-maps appended to Dr. MacCulloch's 

 "Account of Guernsey and the other Channel Islands" in the first volume of the 

 Geological Society's Transactions. The Ordnance maps of Guernsey and Jersey are 

 on a scale of six inches to the mile, and somewhat expensive ; but very good and 

 cheap pocket maps may be had of Guernsey, of Messrs. Staddon and Grigg, High 

 Sti-eet, St. Peter Port ; and of Jersey, at any of the stationers there. 



