LOESS OF CROWLEY'S RIDGE, ARKANSAS 147 



THE LOESS OF CROWLEY'S RIDGE. A R KANSAS. 

 B. SHIMEK. 



Crowley's Ridge is a narrow, more or less interrupted ele- 

 vation which extends from southeastern Missouri to Helena, 

 Arkansas. 1 Its slopes, especially on the eastern side, are fre- 

 quently quite abrupt (see Plate V, figure 1), and it forms a 

 striking topographic feature of this part of the Mississippi val- 

 ley. 



It has received some notice from geologists. Owen refers to 

 it in both the First (1858) and Second (1860) Arkansas Re- 

 ports; and Call has given the most complete account of its ge- 

 ology, 2 including a chapter by Salisbury; and Chamberlin in- 

 cluded a discussion of it in his paper on the Interval between the 

 Glacial Epochs. 3 



The loess of the southern part of this ridge presents certain 

 interesting features, and it has received some previous attention, 

 especially from Call. Some years ago (1907) the writer visited 

 the southern part of Crowley \s Ridge and made some studies of 

 the loess, the results of which have not been published because it 

 was planned to extend the observations along the entire ridge. 

 As this has not yet been possible, the report on the southern por- 

 tion of the ridge is here presented. 



Two distinct sections of the ridge were studied. The first is a 

 detached portion about seventeen miles long, which extends from 

 Helena to Marianna, and is cut off from the main ridge to the 

 north by the valley of the L'Anguille river. The second is that 

 part of the ridge extending from the L'Anguille valley to Forrest 

 City and Madison. 



The finest exposures were found in Helena, along the eastern 

 slope of Crowley's Ridge, particularly that part lying west of 

 Poplar street, between Louisiana and "Walker streets. Three of 

 these exposures are figured on Plate V, figure 2; Plate VA, 

 figure 1, and Plate VB, figure 2. 



J It is mapped in the Arkansas Geological Reports, Vol. II, 1891. 



2 Geol. Survey of Arkansas, Vol. II, 1891. 



bulletin of the Geological Society of America, Vol. I, 1S90, pp. 469-80. 



