MINERALOGY. 399 



FIRST CLASS. PRIMARY OR STRATIFIED ROCK FORM- 

 ATION. 



FIRST ORDER : Transition Rock Formation. Sedimentary. 



SECOND ORDER : Tertiaiy Rock Formation. 



THIRD ORDER : Secondary or Unstratified (Floetzgebirg Flat Rock) 



Rock Formation. 

 FOURTH ORDER : Diluvial and Alluvial Deposits. 



geologists have divided them into two great classes, namely the 

 Sedimentary or Stratified Formations and the Massif or Igneous 

 Formations. On account of the presumed method of their pro- 

 duction they are also designated under the names of Aqueous 

 or Neptunian Formations, and Igneous or Plutonic Formations. 

 The first, which was the theory of the celebrated Werner, affected 

 to prove that the present appearances of the globe may be traced, 

 with the exception of volcanic products, entirely to the agency 

 of water, to aqueous solution, disintegration, and deposition, and are 

 termed stratified formations and most of them sedimentary forma- 

 tions. These deposits formed a variety of crystalline aggregates, 

 such as granite, primitive, slate, and limestone, and constitute the 

 primary rocks, supposed to have had their origin at the earliest geol- 

 ogical epoch. The second class of rocks is supposed to have been 

 formed during the transition of the earth from its chaotic .to its habit- 

 able state, and are called transition rocks. The third class of rocks 

 is supposed to have been formed by the action of the natural ele- 

 ments on these, and by which they have been broken down and 

 mechanically diffused by water. The action of frost, water, and. 

 attrition are supposed chiefly to have produced this effect, after 

 which the materials were deposited in horizontal strata. These are 

 the Floetz or flat rocks of Werner, and the tertiary or secondary rocks 

 of later authors. They abound in vegetable and animal remains. 

 The Plutonic rock formation is attributed to the agency of fire, not 

 entirely rejecting that of water. According to this theory the mate- 

 rials which compose the present surface of the globe, have been 

 derived from the ruin of ancient rocks which have been disintegrated 

 and pulverized by the continued action of water, and transported by 

 the same means to the bottom of the sea. Here they have been con- 

 solidated partly by time and partly by the pressure of the water, but 

 chiefly by the effects of subterranean heat. By the expansive power 



