NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 23 



a man's hand. In places these thin layers are marked by parallel varicose lines 

 which seem to be wave-marks. In other places the division planes are themselves 

 thrown mto very shallow, hardly perceptible folds, a few inches wide. These are 

 evidently incipient ripple-marks, for in some places they are found in association 

 with well-developed npples. Ripple-marks are not very common features in the 

 bedding of these sands, and were noted at only a few places in this field. 

 Cross-bedding. 



"The most frequent and conspicuous bedding characteristic of the Wichita 

 sandstones is cross-bedding or so-called false bedding. There are few outcrops of 

 sandstone where this form of stratification may not be found. The thinness of the 

 beds m this field prevents it from being developed on a grand scale. The thickest 

 single cross-bedded strata noted here are not more than 3 feet in thickness, and the 

 common thickness of single layers of this kind is less than a foot. On the other 

 hand, the development of small, fine work in cross-bedding seems to have reached a 

 culmination in these sands. Layers no more than a half-inch thick are often seen 

 to be quite regularly cross-bedded. It is evident that this cross-bedding is the 

 result of currents in the direction of the slant of the false bedding. These slants 

 are, in each case, the indices of local currents which produce them. In each out- 

 crop there may often be found several directions of these slants, but usually one 

 or two directions prevail. For the purpose of securing some information on the 

 general direction of the transporting currents which brought this sand, some obser- 

 vations were made on the direction of the slants in the false bedding of the thickest 

 strata. Each slant noted was referred to one of eight directions of the compass, 

 the four cardinal points and the four intermediate points. In all, 125 observations 

 were taken, 30 in Clay County and 95 in Wichita County.* 

 Significance of Cross-bedding. 



"The greater frequency of the westwardly directed depositing currents is clearly 

 shown by these observations. It would, nevertheless, be hasty to conclude that 

 the resultant direction is a true index of the direction from the land to the sea at 

 the time of the making of those beds. The general direction of transportation in 

 sand bars and sand beaches is not always from the land seaward. It may as well 

 be parallel with the coast-Hne. But it can not be largely from the sea landward. 

 All that we may safely infer from these observations is that the land at that time 

 was not to the west with the sea to the east. If the ancient shore-line extended in 

 a north and south direction, there must have been an open sea to the west. But 

 if the course of the shore-line was from the east to the west, the land may, so far 

 as these observations are concerned, have been somewhere in a northeast or an 

 east direction. The northward trend of the resultants renders it unlikely that the 

 shore-Hne extended in an east-west course, as this would require a landward trans- 

 portation of the sand. The land, hence, probably lay to the east, southeast, or 

 northeast, all evidence considered, with an open sea to the west, northwest, or to 

 the southwest. ^ 



Small Contemporaneous Faulting. 



"Some thin and fine-grained layers of sandstone which are interbedded in the 

 red shales in the breaks of Bluff Creek, southwest of Electra, exhibit a peculiar 



" The average direction of the inclination was 2° north of west. — E. C. C. 



*■ Udden's conclusions do not necessarily follow from his observations. It is very probable that the 

 sandstones with their observed dips were deposited in pools on the surface of the subaerial portion of the 

 delta plain and not upon a sea-shore. Other evidence clearly shows that there was a sea to the east and land 

 to the west and north. — E. C. C. 



