METAMOB 



The Metamorpliic Hocks generally lie over or against the igneous rocks, and exhibit raos 

 a schistose and stratified character, combined frequently with a highly crystalline structu 

 They are supposed to bear marks of an aqueous origin, subsequently influenced by the act 

 of heat. Another theory supposes them to be broken fragments of igneous rocks, re-arranj 

 into layers or beds by the action of water. 



The Metamorphic Rocks are destitute of organic remains. Veins of copper and lead 

 have been found in these rocks, as also those of iron, silver, gold, tin, &c. 



The Metamorphic Rocks are widely distributed, and form a great part of the earth's cm 

 they are found in Scandinavia, Northern Russia, Ireland, the Highlands of Scotland, the Al 

 in Brazil, India, Africa, and North America. The scenery of the districts composed oi th 

 rocks is frequently wild and picturesque, and the surface often sterile and unproductive, par 

 arising^from themature, but generally from the elevation they attain. 



Gneiss consists of quartz, felspar, mica, and sometimes hornblende, arranged in distil 

 layers; with the latter mineral it may be termed syenitic gneiss. 



Mica Slate is a foliated aggregate of mica and quartz, and sometimes contains crystals 

 garnet and hornblende. 



In Hornblende Slate, hornblende forms the greater part of the composition. It consi 

 of a mixture of hornblende and felspar or quartz, and is called Metamorphic-greenstone or gre 

 stone slate. The metamorphic limestone of the primary period, is often white and crystalli 

 and furnishes some fine marbles, and contains occasionally veins of chlorite, steatite, and soi 

 disseminated minerals, as augite, &c. 



Chlorite Slate consists chiefly of chlorite, sometimes with quartz, felspar, hornblende or mi 



Metamorphic Sandstone, or Quartz Rock is granular, and occasionally occurs as vei 

 in the other rocks. 



Clay Slate is a slaty rock of extremely fine ingredients, containing the elements of t 

 other rocks in a very comminated state, subsequently altered. 



Talcose Slate is a soft, unctuous, and fissile rock, containing 

 talc as an ingredient, generally associated, with quartz. 



Actyiiolite Slate or Schist is slaty rock, formed chiefly of 

 actynolite, with some felspar, quartz or mica. 



Serpentine, although classed with the igneous rocks, may also 

 be considered as belonging to this series. 



The Metamorphic Rocks in the above list may be divided into two SL. 



LONDON: PUBLISHED B 



