Association of American Geologists and Naturalists. 177 
Dr. Dana presented a copy of what was probably the first 
work on the geology of America, entitled “ Beytrage zur miner- 
alogepfer Keintre und des Céstlicheu theils yon Nord America 
und sum Gebiirsge von D. Johamre David Schépf,” presented to 
the library of the Boston Society of Natural History. Mr. Tes- 
chemacher was requested to report on it. 
‘ =e Couthouy read a paper “on various icebergs as observed 
y hi 
_ Mr, a Hail read a paper “on wave lines and other mark- 
ings on the surface of rocky strata in New York and other places.” 
Association adjourned to 340 ‘clock, P. M. 
Friday, 34 0 ‘clock, P. M.—Prof. Silliman in the chair. The 
following gentlemen were announced by the standing committee 
as the local committee for next year. Dr. 7’ Romeyn Beck, Prof. 
E. Emmons, Albany, and Mr. W. C. Redfield, New York. 
 Aletter from Mr. James T'. Hodge, relative to the distribu- 
tion of State Raportey was. read by the secretary. 
A paper was read ‘‘on the Structure of the Appalachian chain, 
as exemplifying the laws which have regulated the clevation of 
great mountain chains generally ;” by Prof. Henry D. Rogers, 
and Prof. William B. Rogers. 
The authors divide their papers into two parts; Part I, being a 
description of the phenomena ;- Part II, a here of the flexure 
Tae sme ene m erste on 
the | vlaethllear 
“Ist 3 eketch of the physical features of the Apalcin chain, 
from New to Alabama. — 
_: eeaid, Predominance of southchster Ee with an. historia sketch 
of the previous explanations offered by other 
~ Brd: Of the character of the flexures of the strata, a pera 
their gradation in crossing the chain northwestward. Two or three 
' Mew terms are here proposed for designating conditions of structure. 
The -several prevailing forms of structure are then exemplified : (a,) 
normal flexures ; (b,):felded flexures and i inversions ; (c,) flexures bro- 
ken on passing into faults. 
«4th. Of the distribution of the axes itt’ gronpiee sgiciiideaite parallel- 
ime of pe axes in beach group ; ‘great longi of some axes ; vai! 
* Mr. partes s sendin have bien already given, p. 154-165, — 
Vol. xz, No. 1.—April-June, 1842. 23 
