PREFACE. 



THE various hints that have been offered, by different writers, 

 on the Geological phenomena, or certain physical changes, 

 that appear to have taken place in other countries, have long 

 since engaged the attention of the author, and led him to ex- 

 amine some of the geological features of our own country, 

 with a view to their origin, and the probable causes, by which 

 they have been produced. 



Among those, the alluvial districts upon the margins of most 

 of the rivers, in the United States, and the great alluvial re- 

 gion, bordering on the Atlantic ocean, appeared the most inte- 

 resting, and most worthy of a critical examination. 



On these subjects, and others, having an intimate relation 

 thereto, a considerable .portion of the present work was writ- 

 ten ; though not with the most distant idea, that it would ever 

 appear before the publick in its present form. 



fThis imperfect sketch, however, was, in 1817, submitted 

 to the perusal of several of his literary friends, among whom 

 was Professor Silliman. It was also read to Dr. S. L. 

 .Mitchell, of New- York. 



From the favourable terms in which it was spoken of, and 

 the friendly encouragement held out, for its publication, he 

 was induced to relinquish the intention of publishing it in 

 detached anonymous sketches ; to enlarge and extend the sub- 

 ject by a more circumstantial investigation of facts, and to 

 offer it to the publick in its present shape. 



