REPORTS 



ON 



THE STATE OF SCIENCE. 



Report on the Geology of North America, Part I., hy Henry 

 i). ROGKRS, F.G.S. 



In obedience to the request of the British Association, ex- 

 pressed to me at the last Annual Meeting, I beg leave to oiFer 

 the following Report on the present state of our knowledge of 

 the geology of North America. 



The magnitude of the region, our remoteness from the foun- 

 tains of science in Europe, and likewise some peculiarities in 

 the geological structure of the country, have operated hitherto to 

 make our efforts in exploring its formations tardy and uncertain. 

 But the friendly interest expressed by the British geologists in 

 our labours is calculated to cheer and quicken our progress. 



It will be seen to be among not the least important of the 

 good results of this Association, that it can invigorate by its 

 ample spirit the youthful science of a distant but kindred con- 

 tinent. 



The plan and object of this Report make it necessary to offer 

 an introductory section on the general physical geography of 

 the country. In no section of the globe will a more obvious 

 and marked connexion be seen between the geographical features 

 of the surface and the geology. Such a description is indispen- 

 sable indeed, for certain geographical boundaries will be found 

 the best, in fact almost the only, guide we possess at present for 

 judging of the probable range and extent of certain formations 

 oveir many extensive districts not yet explored. 



Physical Geography . — Omitting the minor irregularities, and 

 confining our survey to the great masses which compose the 

 continent of North America, its structure will be seen to exhibit 

 great simplicity and regularity. From 1;he Atlantic to the Pa- 

 cific Ocean, and from the Arctic Sea to the Gulf of Mexico, 

 the whole area seems naturally divided into two great plains, 



1834. B 



