NATURAL SCIENCES OF PHILADELPHIA. 129 



The position and vertical range of such fossils as are known to be common 

 to the North West and New Jersey, in the foregoing general section of the 

 Nebraska rocks, clearly establishes, as stated in our paper communicated to 

 the Academy in November last, that formations No. 4 and 5 of the North 

 West, are on a parallel with the beds b. c. d. and e. of the New Jersey serief. 



After a careful reviewiof the subject, we are now satisfied that the parallel- 

 ism of these beds may \ be more closely drawn, or in other words, that the 

 second green sand bed of the New Jersey section rejjresents No. 5 of Nebraska, 

 and that No. 4 of the latter region is on a parallel with the beds c. d. and e. of 

 New Jersey. 



At the same time the identity of No. 1 of the North West, with the beds com- 

 posing f. of the New Jersey section, is scarcely less apparent. It is true tbig 

 latter opinion rests mainly upon stratigraphical and lithological evidence, yet 

 these points of analogy are so strong as to possess great weight. In order 

 that this may be better understood and appreciated, we quote below from 

 notes taken by one of us''*' in 1855, a description of an exposure of No. 1 

 seen on Big Sioux River, which will show, by comparison with the New Jersey 

 section, the striking resemblance between the beds holding a position at the 

 base of the Cretaceous formations at these distantly separated localities. 



" Six miles above the month of Big Sioux River we have an exposure of 

 impure lignite about 12 inches in thickness, underlaid by alternate layers of 

 sandstone, loose clay, yellow and ash colored arenaceous clays, and fine whitish 

 clay. The strata containing clay have quite distinct impressions of leave?. 

 which appear to have belonged to dicotyledonous trees. We have also, near 

 the base of the exposure, some fine impressions of leaves in dark tough gray, 

 siliceous, concretionary rock. Much pyrites and fragments of fossil wood occur 

 in these beds." 



The points of analogy between these lower deposits (No. 1) of the norih-weet, 

 and formation f at the base of theNew Jersey section, as well as with an extensive 

 series of deposits holding the same position in Alabama, (formation E of the 

 Alabama section,) and throughout a great area of country in Arkansas, Tesae, 

 and New Mexico, will be more fully illustrated by the following section taken in 

 north-eastern Kansas, where this series appears to be more extensively de- 

 veloped than at any localities known to us in Nebraska. 



For this section, as well as much other interesting and important information 

 respecting the geology of the country surveyed by him, we are indeb'ed to the 

 kindness of Major F. Hawn, formerly of the geological survey of Missouri, but 

 now connected with the lineal survey of portions of Kansas Territory. We give 

 it exactly as communicated to us by him, excepting that we have thrown it into 

 a tabular form, and added columns showing the parallelism of the beds with 

 those of New Jersey and Nebraska. To those acquainted with Major Hawn, it 

 is unnecessary for us to say he is a careful conscientious observer, whose state- 

 ments are worthy of the fullest confidence. 



The beds represented in this section were not all seen at any one locality, but 

 their thickness, composition and order of succession were determined from ex- 

 aminations made at numerous exposures in the country east of the sixth prin- 

 cipal meridian, between the northern boundary of Kansas and the Republican 

 fork of Kansas River. 



* Dr. Hayden. 



1857.] 



