THE NEW MADRID EARTHQUAKE 



5 1 



Fault scarps. — The fault scarps are a striking feature of the 

 country, especially in the Big Bay district. Two nearly parallel 

 lines of cracks having an east-and-west trend are found near the 

 mouth of Fortune Creek, where it empties into the St. Francis. 

 Others in the same vicinity have a northeast-and-southwest trend, 

 with a present depth of about 4 feet. One of these cracks, illus- 

 trated in the photograph (Fig. 3), has growing from it a tree which 

 is probably seventy-five years old. 



Fig. 3. — Fault scarp, ten miles north of Parkin, Ark., in the Big Bay district. 



Ejection of sand. — Another feature of this region, and one which 

 will be referred to later, is the large amount of white sand that con- 

 stitutes the surface of the New Madrid district. Passing down the 

 Mississippi River from St. Louis, the amount of sand on the banks 

 is not relatively large. On entering the sunken district, we find a 

 small amount of coarse sand, which is evidently derived from the 

 breaking down of the Ordovician and Cambrian sandstones of the 

 country above, and proceeding southward we find a steady increase 

 in the amount of fine white sand which, everywhere forms the sur- 

 face of the flats, reaching a maximum thickness in what is called 

 the "sand slew" country, at the southern end of the area under dis- 



