r;8 NATURE OF STRATIFICATION. 



to be accomplished before even the stratified rocks of Europe can be 

 completely compared with those of England, and the want of evidence 

 is still more severely felt with respect to other quarters of the globe. 

 Nevertheless, the following important general results may be regarded 

 as certain. The principle of stratification is found to be universal ; 

 that is to say, in every country of sufficient extent, various rocks are 

 found to be superimposed on one another in a certain settled order of 

 succession, and these rocks are not found only in isolated patches, 

 but often hold their course across provinces and kingdoms. 



Throughout the whole area of Europe, from the Ural Mountains 

 to the Atlantic, and from Lapland to the Mediterranean, the stratified 

 masses, taken in their generalities, are arranged upon the same princi- 

 ples, follow one another in the same exact order of succession, and, in 

 fact, form parts of one vast system of rocks, once more perfectly 

 connected than at present. 



What is known of the geology of North Africa, Egypt, Syria, the 

 countries bordering on the Caspian, Siberia, and Hindustan, leads to 

 a confident belief that the same general system, modified by local cir- 

 cumstances, will be found also applicable to the greater portion of 

 the surface of the Old Continent. 



Analogy of Distant Deposits. Important agreements between 

 the strata of North America, India, Australia, &c., and those of 

 Europe, have been clearly determined, and the time will probably 

 arrive, when, though it cannot be proved that similar rocks were at 

 the same time deposited in every part of the bed of an ancient sea, at 

 least it will be possible to show, that the same system of natural pro- 

 cesses was everywhere in progress, contemporaneously or successively 

 producing analogous effects ; thus exhibiting in chronological order, 

 through the relative antiquity and accompanying circumstances of even 

 the most distant deposits, a history of all the varied operations by 

 which in regular gradation our globe has arrived at its present state. 



Distinction of Stratified and Unstratified Rocks. 



Relative Situation. Stratification is, therefore, the most general 

 condition or mode of arrangement of the rocks ; and in the wide plains 

 and gently undulated portions of the surface, it is often the only one 

 discoverable. A person of good discernment, who should pass his 

 whole life in investigating the south-eastern part of England, or the 

 northern part of France, might conclude, from every observation he 

 could there make, that the external materials of the earth were uni- 

 versally stratified, this arising from the fact that no unstratified masses, 

 igneous or otherwise, occur in these areas. 



On the other hand, the inhabitant of the mountains sees so many 

 examples of granitic and other rocks, totally devoid of any appearance 

 of stratification, and sometimes finds that structure in the slate rocks 

 so dubious and inconclusive, that he is wholly unable to comprehend 

 the magnificent chain of inductions derived from the study of stratified 

 rocks. Unstratified rocks generally abound along mountain chains and 



i 



