CHAPTER XIV. 



THE OOLITIC GROUP. 



Oolite formation of English; Calcaire Jurassique of French; Jurakalk, and 

 Rogenstein of German Authors. 



MUSEUMS: Geological Society; British Museum; that of Dr. Buckland ; 

 the Bristol, York, Scarborough, Hull, Whitby, and Grantham Museums; 

 with numerous private Collections. 



AUTHORS : Buckland, Lonsdale, Smith, Phillips, De la Beche, Murchison, 

 Boblaye, De Caumont, Desnoyers, Goldfuss, Roemer, D'Orbigny, &c. 



CHARACTERISTICS : Marine, containing the usual Marine Exuviae, with 

 organic remains drifted from the Land, among which are the jaws of 

 Mammalia, of the Marsupial Order. 



DESCENDING a step in the scale of deposits, we reach the 

 oolitic group, which underlies the wealden, or, where this is 

 wanting, the chalk formation. Its name is derived from the 

 Greek words, utov, an egg, and Ai&>?, a stone, because it is 

 formed of small egg-like grains, like those composing the 

 roe of a fish, the nucleus of which, on microscopic investiga- 

 tion, is found to be some minute substance, usually a frag- 

 ment of a coral, a shell, or a grain of sand. 



GrEO GRAPHICAL DISTRIBUTION OF THE OOLITE. ThlS 



group commences at the Isle of Portland, and the adjacent 

 coast of Dorset ; and follows a winding course through the 

 counties of Dorset, Somerset, Gloucester, Oxford, Northamp- 

 ton, Lincoln, and York, where it terminates at the sea, near 

 Scarborough. On the Continent, it occurs in Normandy ; 

 and, diverging into various branches of hills, traverses France, 

 forms the mass of the Jura and part of the Alps, and is 

 farther developed in G-ermany and .Poland, as well as in 

 Portugal and Spain. 



The oolitic group is highly valuable in an economical point 



