119. 

 area underlain by rock salt is shown on Figure 5. 



3.6 In Kansas , beds of rock salt occur in several formations of Permian 

 ageA ' The Hutchison member of the Wellington formation and the 

 Ninnescah shale (both of Middle Permian age) are the most important 

 salt-bearing units, although salt is also found in the Harper, Salt Plain 

 and Flowerpit formations higher in the Permian section. The eastern 

 outcrop of the Hutchison salt member is along a line extending north 



and south from Saline to Sumner county. The salt at the outcrop is dis- 

 solved but dips westward under cover, and is about 650 feet below the 

 surface at Hutchison; 1000 feet at Lyons; and 850 feet at Ellsworth. 

 Farther west, the top of this salt is about 1700 feet in Kiowa County and 

 2000 feet in Clark County, and its thickness is usually from 200 to 300 

 feet. 



The higher salt horizons underlie the southwestern part of the state. 

 The Ninnescah salt is at a depth of about 1250 feet in Kiowa County, 

 1000-1500 feet in Clark County; and 1600 feet in Meade and Gray coun- 

 ties. The total thickness of salt in this part of the section ranges from 

 200 to 300 feet. 



Altogether, about 30,000 square miles in the central and southeast 

 parts of Kansas are underlain by salt-bearing formations. 



3.7 A large area on the Gulf Coast contains numerous structural uplifts 

 which are considered to have resulted from the flowage of salt.(H) In 

 many of these uplifts the salt has flowed upward through the overlying 

 beds to form salt domes. Exploratory drilling has proved the existence 

 of a large number of salt domes and, on the basis of geophysical evi- 

 dence, it is thought that salt forms the core of others. In northern 

 Louisiana, southern Arkansas and east Texas, bedded rock salt of 

 Jurassic (or Permian) age has been reached in widely separated wells. 

 The Eagle Mills (Louann) salt is seldom fully penetrated in wells but 

 thicknesses of 500 to 1500 feet are normal. It is estimated that this 

 horizon underlies an area of 180,000 square miles on the Gulf Coast. 



The known salt domes are over 200 in number. ' In a few domes the 

 salt is very near the surface but in many others it is below 5000 feet, 

 and, in some instances, over 10,000 feet. The piercement-type domes 

 that come nearest to the surface range in size from nearly circular 

 domes a half-mile to two miles in diameter to elongated masses several 

 miles in length. The best known group of salt domes is the Five Islands 

 of southern Louisiana, characterized by surface uplifts overlying the 



