Page:History of Southeast Missouri 1912 Volume 1.djvu/282

 222 HISTORY OF SOUTHEAST MISSOURI carbonized wood reduced mostly into dust, which was ejected to the height of 10 and 15 feet and fell in a black shower mixed with the sand which its rapid motion had forced along. At the same time the roar and whis- tling produced by the impetuosity of the air escaping from its confinement seemed to in- crease the horrible disorder. * * * i^ the meantime the surface was sinking and a black liquid was rising to the saddle-girths of my horse."* Great quantities of this water were thrown out. Flint says that the amount ejected in the neighborhood of Little Prairie was suffi- cient to cover a tract many miles in extent from three to four feet deep. Some districts were still covered when he saw them seven years after the earthquake.! Out of the fissures and small craters there was blown, along with other material of vari- ous kinds, great quantities of sand, which eame from below the strata of clay which underlies the alluvial top soil of the district. It was in this sand that the lignite was prin- cipally contained. The sand thus ejected formed the sand blows characteristic of part of the New Madrid area. The name seems to have been given them from the fact that the sand was blown out of the craters or fissures. The ordinary sand blow is a patch of sand nearly circular in shape, from 8 to 15 feet across, and a few inches higher than the .surroimding soil. Some of them are much larger and many of them are not circular. The material contained in the sand blows is a white quartz sand, mixed in some cases with clay, and in nearly all cases with lignite. These sand blows at the present time are Vol. Ill, p. 15. + Flint, Eeeollections of the Last Ten Years, p. 222. found scattered over a considerable part of the area covered by the- earthquake. They da not occur, however, in all parts of it. They are not found immediately along the river nor seldom upon the domes or wplifts previ- ously described. ]Iany of them are to be found in the neighborhood of New Madrid, along the railroad leading to Campbell, about Campbell, in the neighborhood of Lilbourn and Portageville. There are also many be- tween Hayti and Caruthersville, and about Pascola. and some are found on the ridge extending south from Dexter, especially in the southern part of Dunklin county. The origin of these sand blows, as we have said, seems fairly evident. Out of the cracks opened in the alluvial top soil was forced sand and water in the form of a fountain and the sand was distributed over a .small area about this crack. Besides the sand blows there are certain depressions three to five feet in depth bor- dered on either side by ridges of sand parallel with one another, which are called sand sloughs. Some of these sloughs are wide and they are found only in the lower lands of the district. It has been considered by some stu- dents that they were formed at the time of the earthquake. The fissures which were opened were in many cases large, and out of them were forced enormous quantities of sand, which was piled in ridges coinciding in part with the sides of the fissures and spread over the area between them, helping to form the channel now Imown as a sand slough. Of the phenomena of the earthquake among the most interesting are the sinks still to be seen in some places of the earthquake area. They are perhaps the most conspicuous of all the evidences of the shocks and perhaps the rarest. They are circular depressions in the alluvium originally from a few feet up to fifteen yards or more in diameter, and from
 * Bringier, Amer. Jour, of Science, 1st Series,