SUCCESSIVE DEPOSITS IN THE APPALACHIAN REGION 489 



to possess in the main the features of a subaerial deposit. Such an origin 

 is suggested by the red color, which indicates thorough oxidation of the 

 deposit, by the mud-cracks and rill-marks in the shaly beds, by the abun- 

 dance of clay galls in all of the sandstones, by the cross-bedding of the 

 deposits, which in the coarser beds is of torrential type and in others of 

 the eolian type, and by the irregularity of the sandstone members which 

 locally wedge out, and by frequent evidence of contemporaneous erosion 

 and deposition. Eipple-marks also occur, these, where I have observed 

 them, suggesting an eolian origin. Finally, the general absence of fos- 

 sils, except where the formation rests upon the underlying fossiliferous 

 strata, with which it forms a continuous depositional series, is certainly 

 significant. The fact . that fossils do occur in some of the lower beds 

 shows that there is nothing in this red rock material itself which pre- 

 vented the existence of marine organisms while it was being deposited 

 and nothing to prevent their subsequent preservation. The presence of 

 these fossils in the lower beds and their absence throughout the upper 

 beds indicates that the lower beds were locally dipping into the sea, but 

 that subsequent withdrawal of the sea from the area of deposition left 

 the higher beds to be deposited as subaerial sediments.* 



The extensive oxidation of these sand and dust deposits, as well as the 

 general absence of all traces of vegetation, suggest that arid climatic con- 

 ditions prevailed during the deposition of these beds. The presence of 

 saline springs in the Queenston of western New York tends to confirm 

 this interpretation. Whether winds or streams were the chief agents in 

 the deposition of these oxidized (now red) beds might be a subject for 

 difference of opinion, I am disposed to give the wind a large if not the 

 largest share of credit for the distribution of these deposits, but the con- 

 firmation or refutation of such a supposition requires extensive micro- 

 scopic study of these sandstones which has not yet been undertaken. At 

 the commencement of deposition of these red beds on the previous delta 

 of coarser white quartz sands and pebbles, this latter was to a certain 

 extent reworked, and as a result the contact may in souk 1 eases be abrupt ; 

 in others more or less transitional. The fact that the beds in western 

 New York have practically the same thickness as those in central Penn- 

 sylvania shows that the Juniata was not a new fan huilt on tin 1 Bald 

 Eagle fan, but that it represents in the main the continuance of that 

 deposition which had commenced in Lorraine time, forming the Bald 

 Eagle, only under somewhat differenl climatic conditions. The same 



* For a general discussion of the characters of river deposits, sec the author's "Prin 

 clples of Stratigraphy," 1913, chapter xiv. Original structures and lithogenesls of the 

 continental hydroclastics for the characters or eolian rocks, sec chapter \iii. 



