oill GREATEST EARTHQUAKES 79 



Some, like the first, were accompanied by disruptions of the surface 

 and by changes in elevation of the ground. The country which before 

 the shocks was level, with occasional small prairies, was sadly changed. 

 In places old bayou-lakes were drained so that corn could be planted in 

 their bottoms, while elsewhere lakes of considerable size were created. 

 The surface for hundreds of acres was covered by the sand thrown 

 up with the water from the fissures. Even to this day this can be 

 recognized in the forest, where it occurs as barren spots upon which 

 little will grow. 



A few more years and a century will have passed since the shocks 

 so vividly described took place. From a wilderness with a few scat- 

 tered settlements, the region has become, in the northern part at least. 

 a populous farming region with numerous prosperous towns. The 

 great city of Memphis has appeared near the limits of the earthquake 

 region at the south, while St. Louis with its hundreds of thousands 

 of people is but a little distance outside the area to the north. 



Notwithstanding the development of the region and modification of 

 the surface by nearly a hundred years of cultivation, the watchful eye 

 can still detect evidences of the powerful forces which so strongly 

 affected the area in 1811. Throughout all the country from New 

 Madrid in Missouri southward to beyond the Arkansas line, and from 

 the Mississippi river westward to the highlands of Crowleys Ridge, 

 there is hardly an open field which does not show one or more low 

 swells of light sand standing out in marked contrast with the dark 

 soil constituting the ordinary surface. These are the well-known ' sand 

 blows ' produced by the actual eruptions of sand and water from 

 considerable depths through cracks in the clayey surface deposits. 



Some of the cracks were of considerable length, giving rise to the 

 long narrow ' sand blows/ while others were very short, almost all the 

 water and sand coming from a single point. In such instances little 

 cones or craterlets, as they are called, consisting of low mounds of sand 

 with depressions in the center were often formed. 



Even more conspicuous, though less numerous, are the great cracks 

 formed in the earth at the time of the quake. Few people have 

 seen these in their full development, as they are hidden in tangles of 

 vines in the as yet almost untouched hardwood forests on the bottoms 

 of northeastern Arkansas. Turning northward from the lumber town 

 of Parkin about thirty miles due west of Memphis and following 

 the old ' De Soto trail/ in a few hours one reaches the southern portion 

 of the earthquake area and is in the midst of earthquake features of 

 surprising magnitude. The region is low and is frequently submerged 

 for weeks in the spring by backwater from the sluggish rivers, while 

 in summer the cane brakes in the more open spots and the thickets 

 of poison ivy and other vines in the forests present additional obstacles 

 to the explorer. Wild turkeys, deer, wild cats and even wolves are still 



