618 NEW YOEK STATE MUSEUM 



brick clay lias been developed at Cloverport, and in Grayson near 

 Millwood, about 80 miles from Louisville, it being worked at this 

 point by the Louisville sewer co. 



Potters' clay is found cbiefly in the Tertiary beds which are 

 found in the Jackson purchase. This region includes the counties 

 of Calloway, Graves, Marshall, Hickman, Fulton, Butler, Edmon- 

 son, Grayson, Ohio and Madison. The best developed mine is 

 that at Pyorsburg, 6 miles from Mayfield in Graves co. ; the- clay 

 at this point is over 40 feet thick, a most excellent grade of ball 

 clay. 



Glass pot clays are said to exist in Bell, Marshall, McOracken, 

 Carlisle, Hickman, Fulton and Calloway co., but their value has 

 not yet been commercially demonstrated. 



Louisiana^ 



The clays of Louisiana are all Post-tertiary and sedimentary in 

 their origin. There are no important residual clays in the state 

 except in one very small area. This is in the northeast corner, 

 near the Arkansas line. Three distinct types of clay are worked 

 in Louisiana, each being characteristic of the section of the state 

 in which it is found. The oldest of these geologically is the mot- 

 tled gray clay of southeast and southwest Louisiana. These clays 

 are of early Columbian age, and constitute the pine flats of the 

 coast and the second bottoms of the coastal streams. They have 

 been worked for a long time locally for the manufacture of com- 

 mon building brick. But only in the last few years have they 

 been utilized on a large scale. 



The next important group of clays is of a later Columbian age 

 and is found above the alluvial valley of the modem Mississippi 

 river. They form a continuous bluff overlooking the river from 

 the Mississippi state line to Baton Eouge. Thence they bear south- 

 eastward to near Lake Maurepas. These clays have been exten- 



1 Engineering journal. 15 Oct. 1898. See also paper by H. Ries in 1st 

 Ann. rep't La. state geologist. 



