CAINOZOIC OR TERTIARY. 



OZOIC OR SECONDARY. 



3IMENTARY EOCKS. 



ivonshire, with a greater development of limestones, (ornamental marbles, &c.) and con- 

 ning many species of corals, shells, and some trilobites. 



rhe Carboniferous group, so called from being the depository of the important substance, 

 il. A limestone shale usually interposes between the carboniferous limestone and the old 

 I san Istqne. Next above is a deposit of hard, coarse sandstone, called millstone grit; and 

 Dve this occurs an important series of sands and shales, called coal measures, and which 

 terstratified with them,) contain the valuable mineral, coal. They are widely distributed in 

 > British Isles, Belgium, Germany, France, Spain, America, Asia, &c. 



Ilie Permian group, or upper member of the primary series, includes sandstones, marl 

 te, gypseous beds, and magnesian limestones, some of the latter are durable building stones. 

 Germany, this group contains a thin band of copper slate, from which copper is obtained. 



MESOZOIC, OR SECONDARY SERIES. 



rhe secondary series comprise a set of alternating strata of sand, clay, and earthy lime- 

 >nes, generally less indurated than those of the primary series. In an economical point of 

 ;w, they are not less important; the rich deposits of rock-salt and beds of gypsum, as well 

 some good sandstones, belong to the triassic or lower portion of this series. From some of 

 3 lias clays alum is made, and jet is obtained; the finer oolitic limestones are extensively 

 >rked near Cheltenham, Bath, and in the Isle of Portland; the Purbeck and Wealden strata 

 jld some marbles which were largely used in many of the earlier churches and other edifices, 

 le cretaceous group is valuable for the lime, beds of flint, firestone, fuller's earth, &c.; while 

 ue portions of the lower chalk yield abundance of phosphatic nodules, useful in agriculture. 

 The Lower Secondary or Triassic group, includes the variegated sandstone, muschel- 

 1k, (wanting in England,) and the upper new red sandstone or variegated marl The latter 

 ntains gypsum (plaster of Paris) and large deposits of rock salt. 



The Middle Secondary comprises the liassic group; the oolitic or Jurassic group, which 

 sub-divided into three parts ; and the purbeck and wealden groups. 



The Upper Secondary or Cretaceous group, includes the lower green-sand, gault, upper 

 een-sand, and the chalk strata. 



CAINOZOIC, OR TERTIARY SERIES. 



The tertiary series are not so economically important. Cement stones are obtained' from 

 e London clay, which is also used for the manufacture of tiles ; bricks are chiefly made from 

 e clay and loam beds of the upper part of this series, and which generally occur along the 

 esent river courses, and frequently contain remains of extinct mammalia, associated with 

 ing fresh-water and land shells. Some portions of the crag deposits in Suffolk are exten- 

 rely worked for argillaceous nodules, highly impregnated with phosphatic matter, and which 

 ter undergoing a certain process, form a highly valuable manure. 



The Lower Tertiary or Eocene, includes the Thanet sand, Woolwich beds, and the 

 mdon clay, the beds of the Paris basin, and also of Belgium, the Bracklesham and Barton 

 rata of Sussex and Hampshire, and the fluvio-marine beds of the Isle of Wight. 

 The Middle Tertiary or Miocene, includes the upper molasse of Switzerland, the brown 

 >al deposits of Germany, &c., the faluns of Touraine, the beds near Bordeaux, &c. in France. 

 The Upper Tertiary Or Pliocene, comprises the coralline or red crag, sub-appenine beds, 

 ift, also the alluvial and diluvial deposits, the fresh- water beds, and the gravel deposits. 



REYNOLDS, 174, STRAND. 



