STEPHENSON: TONGUE, A NEW TERM 247 



reference. Four tongues have been differentiated by the writer 

 in the Cretaceous deposits of the eastern Gulf region, three in 

 Mississippi, and one in Alabama, each large enough for represen- 

 tation even on a one to one million scale map. The three 

 tongues in Mississippi and the major formations and members 

 with which they are closely interrelated are shown in figure 2. 



As the mention of these examples is in effect the introduction 

 of new geologic names, brief definitions are added. More com- 

 prehensive definitions and descriptions will appear in a forth- 

 coming report on the stratigraphy of the Cretaceous deposits of 

 Mississippi. 



Mooreville tongue of Selma chalk. The basal part of the Selma 

 chalk of east-central Mississippi is represented in northern Mis- 

 sissippi by contemporaneous non-chalky strata, chiefly sands 

 with subordinate amounts of clay, belonging to the Coffee sand 

 member of the Eutaw. The passage from chalk to sand takes 

 place in western Itawamba and eastern Lee Counties, and is 

 accomplished by the intertongueing of chalk and sand, and by 

 the merging of the one kind of deposit into the other. Two 

 conspicuous tongues are developed, one of impure chalk, here 

 named the Mooreville tongue, which projects from the basal 

 part of the chalk northward into the Eutaw type of deposits, and 

 another of sand, the Tupelo tongue, which extends southward 

 from the Coffee sand member of the Eutaw formation into the 

 chalk, the Mooreville tongue below interlocking with the Tupelo 

 tongue above. These relations are diagrammatically shown in 

 figure 2. 



The material composing the Mooreville tongue consists chiefly 

 of argillaceous chalk and shaly chalky clay or marl. An expos- 

 ure along the Fulton road, f mile west of Mooreville, Lee County, 

 may be regarded as typical. Here the top of the hill is capped 

 with about 8 feet of red weathered sand of the Tupelo tongue of 

 the Coffee sand, beneath which in the road cut is about 20 feet 

 of dark shaly clay from which most of the lime has been dis- 

 solved and removed by percolating waters, followed in a deep 

 gully south of the road by about 20 feet of greenish-gray shaly 

 chalky clay, containing small crystals of gypsum in the joint 



