528 



Classification of Rocks. 



[Nov. 



Superior 

 Strati- 

 fied, or 

 Fossili- 



FEROUS. 



De la Beche. Improved n^-h*™.* Omalius <t Brongniart, 



(Detritus of various 1 Wernerian. t-onvoeaie. Halloyi 1830 . im . 

 eludes P now UC fn a/- I Alluvion, 

 tion ; Coral islands ; 

 Travertino, &c. J 



2. Erratic 

 Block 

 Group. 



3. Super- 

 creta- 

 ceous 

 Group. 



4. Creta- 

 ceous 

 Group. 



5. Oolitic 

 Group. 



6. Red 

 Sand- 

 stone 

 Group. 



Transported boul- } 

 ders and blocks; gra- 

 vels on hills and 

 plains, apparently 

 produced by greater 

 forces than those 

 now in action. 



Various deposits 

 above the chalk, 

 such as, in England, 

 the Crag, Isle of 

 Wight beds, London 

 and Plastic clays. In 

 France, the freshwa- 

 ter and marine rocks 

 of Paris, &c 



' 1. Chalk. 2. Up- ' 

 per green-sand. 3. 

 Gault. 4. Lower 

 green-sand. 



To which may be 

 added, for conveni- 

 ence, 



1. Weald clay. 2. 

 Hastings sands. 3. 

 .Purbeck beds. 



The rocks usually 

 known as the Oolite 

 formation, includ- 

 ing the Lias. 



1. Variegated or 

 Red marl. 2. Mus- 

 chelkalk. 3. Red 

 sandstone. 4. Zech- 

 stein ; and 5. Red 

 . conglomerate. 



Diluvium: 



Ancient 



Alluvion. 



-Tertiary. 



Superi- 

 - or Or- 

 der. 



Alluvial and "k -a 



Lysian >.2 



rocks. 



Clysmian 

 rocks. 



Tertia- 

 ry rocks. 



(1. Coal measures. 

 2. Carboniferous 

 limestone. 

 3. Old red sand- 

 stone. 



Secondary 



Super- Ammo- 

 medial 5- nean 

 Order. rocks. 



Izemian 

 rocks. 



Grau- 

 wacke 

 Group. 



Grauwacke, thick- 

 bedded and schistose, 

 sometimes red ; 

 Grauwacke lime- 

 stones ; Grauwacke 

 . clay slates, &c. 



(Various slates, fre- 

 quently mixed with 

 stratified compounds 

 resembling those of 

 the unstratified 

 rocks 



Transi- 

 tion. • • • 



I Medial. 



Subme- 

 dial Or- 

 der. 



Inferior 

 Strati- 

 fied, or. 

 Non- 

 Fossili- 



FEROUS. 



Various schistose ") 

 rocks.andmanycrys- j 

 talline stratified 

 "j compounds, such as 

 - (Gneiss, Protogine, 



Hemi- 

 lysian 

 rocks. 



No deter- 

 minate 

 order of 



sition. 



Primitive, 

 or Pri- {• 

 mary I 



Inferior 

 Order. 



Hemi- 



- lysian 



rocks. 



f Volcanic, 

 Trappe- 

 an, Ser- - 

 pentinous, 

 and Grani- 

 tic rocks. 



Ancient and mo- 

 dern Lava, Trachyte, 

 Basalt, Green-stone, 

 Corneans, Augite & 

 Hornblende Porphy- 

 ries, Serpentine, Di- 

 allage rock, Sienite, 

 Quartziferous Por- 

 phyry, Granite, &c. 



") Arranged ' 

 among the 

 stratified 

 rocks, ac- 

 cording to 

 the order 

 in which 

 they are 

 supposed 

 to occur. 



The 

 same as 

 the im- 

 proved 

 Werne- 

 rian. 



Pyroi- 

 dal & A- 

 galysian 

 rocks. 



Agaly- 

 sian 

 rocks. 



Modern vol- 

 canic rocks, 

 class 'd as 

 pyrogene- 

 ous rocks j 

 igneous 

 rocks of an 

 older date, 

 as Typho- 

 nian. 



