xlvi PEOCEEDIIS^GS OP THE GEOLOGICAL SOCIETY. 



effected by a general map of the Austrian monarchy, which I am 

 preparing from our Government Geological Surveys. It will be in 

 twelve sheets, of which one (No. 5), containing the western Alpine 

 districts, appeared last year, whilst a second, the eastern Alpine 

 country, will be ready to send out in a few weeks. 



" I have done myself the pleasure of sending to you, and also to the 

 Geological Society, copies of the first sheet." 



Geology of the Western United States. — For many years past we 

 have had to welcome, from time to time, the appearance of the 

 oflScial Surveys and Reports which have been executed at the charge 

 of the several States of the American Union, by geologists of high 

 reputation and untiring perseverance. The two handsome volumes 

 recently published under the authority of the legislature of Illinois 

 present us with the results of the labours, commenced early in 1858, 

 of Mr. A. H. Worthen and his assistants. Prof. Whitney, Prof. Les- 

 quereux, and Mr. Henry Engelmann, in the examination and de- 

 scription of a tract 378 miles long by 210 at its extreme width, 

 included within the limits of the State of Illinois. It is to be hoped 

 that a third volume, the materials of which are already collected, 

 will ere long appear, an equally good specimen of paper and typo- 

 graphy, in spite of a certain party opposition which has delayed the 

 publication of matter perhaps even more useful to residents than to 

 the friends of science at a distance. "We had in some measure been 

 prepared by the earlier surveys of other of the Western States for 

 the comparatively monotonous and uneventful geological structure of 

 these extensive tracts ; but the very simplicity of the features confers 

 an importance of a social kind on the broad prairies, the gently 

 undulating coal-field, and the slightly elevated hills of the lead- 

 bearing limestones, all now being rapidly inundated by the advancing 

 tide of population. 



The course of the river-valleys is occupied by beds of the fine 

 freshwater quaternary deposit which the American geologists have 

 agxeed to term loess, measuring from 20 to 60 feet thick in the river- 

 banks and thinning out up the country, and testifying to the former 

 presence of a chain of lakes. Above this is found, through a large 

 portion of the district, a detritus formed of materials many of which, 

 as fragments of the red sandstone and native copper of Lake Supe- 

 rior, have evidently been swept southwards from their native beds, 

 whilst the underlying limestones, when the gravels rest immediately 

 on the rock, offer in their polished and grooved surfaces distinct 

 evidence of long- continued glacial action. A singular exception is 

 the slightly elevated plateau of some fifty miles in length, trending 

 east and west, on the south side of the Wisconsin river, where a 

 total absence of the foreign drift, so abundant elsewhere, and even 

 on the higher ground, marks the productive lead-bearing region which 

 extends from this State into Iowa and south-western Wisconsin. 



Tertiary strata of but small importance are shown to exist in the 

 southern part of the State, especially in Pulaski county, whilst the 

 whole of the Mesozoic or Secondary formations appear to be absent, 

 and the alleged Permian rocks, containing fossils very similar to 



