220 SIXTEENTH REPORT ON THE CABINET OF NAT. HISTORY. 



Dr. Owen, at a later period, in making investigations from the 

 Mississippi valley to Lake Superior, has very clearly shown the 

 probability, if not the ascertained certainty, that the Red sand- 

 stone of the western part of Lake Superior is inferior to the 

 fossiliferous sandstones of the Upper Mississippi and St. Croix 

 valleys; and he suggests that the latter may lie uncouformably 

 upon the disturbed and uptilted formation below. 



From the disturbed and highly inclined position of the inter- 

 stratified conglomerates and sandstones on the northern and 

 eastern shores of Lake Superior, Sir William Logan has become 

 convinced that these deposits are older formations, and uncon- 

 formable to the sandstone of the south shore from Keweena point 

 to the eastward. 



The testimony, therefore, of all those who have investigated 

 the localities, concurs in recognizing two or more eras in the 

 deposition of the conglomerates and sandstones of the Lake Su- 

 perior region. And while the older beds of that area are apparent- 

 ly below the fossiliferous beds of the Upper Mississippi valley, 

 the newer sandstone of the St. Mary's river, which is apparently 

 of the age of the St. Peters sandstone, or the Chazy formation, 

 w^ill be found overlying the fossiliferous sandstone, either with or 

 without the intervention of the Lower Magnesian limestone. 



I have appended these few facts and arguments, with a view of 

 presenting, in connexion with this notice, some of the points of 

 interest yet remaining undetermined in regard to the older de- 

 posits of the West, and the difficulties in the way of determining 

 their satisfactory parallelism with those of the East, considering 

 simply the sequence of formations as originally presented in the 

 State of New-York. 



( NOTE REFERRED TO ON PAGE 213.) 



This formation, in Canada, lias a thickness of between six and seven hundred feet 

 {Geology of Canada, pp. 88 & 89) ; but even there it is not supposed to n-present the 

 entire })riraordial zone. Nor does the fauna, at present knoAvn, bear so exclusively a 

 primordial character as to lead us to suppose that we have reached the lowest beds. 

 The tj'pical forms of Paradoxides of Braintree, Massachusetts, and of ^Newfound- 

 land, indicate, on palaeontological grounds alone, a lower horizon than any we have 

 reached in New-York, Canada, or in the Mississippi valley. 



I have already noticerl, in the preceding pages, the relations of some of these Tri- 

 lobites with Paradoxides in certain parts of their structure. The condensation of ge- 

 neric characters observed in true Paradoxides (as well as in typical Conjcephalites 

 and Olends) seem to me diffused among the generic forms of the sandstone of the 

 Mississippi valley; on which account alone, I would infer that this fauna is of a later 

 epoch than the oldest primordial fauna, I have made similar observations regarding 

 those forms, sometimes termed Paradoxides. in the older slates of Vermont. 



