208 FLORIDA GEOLOGICAL SUREY-I5TH ANNUAL REPORT

clays occur in this region, but they are unfitted for use in manufactured products.
 UNION COUNTY 
 Union County is located in the northern part of the peninsula. Sandy clays are of common occurrence, but none in which the clay content is high enough for use in burned products.


 VOLUSIA COUNTY
 Volusia County is situated in the north-central part of the peninsula and lies between the St. Johns River and the Atlantic Ocean. The western part of the county is underlain principally by the Nashua marl. Sands, clays and marls comprise the surface formations. Some floodplain clays occur near Lake George in the northwestern part of the county.
 The eastern part of the county has a heavy mantle of Pleistocene sands. One very small clay deposit was worked for common brick long ago on the coast, two miles north of Ormond Beach. The deposit is now covered by a sand dune and only parts of the dismantled machinery may be seen.
 A marl-pit in the south part of the city of DeLand contains an overburden of thin sedimentary clays interbedded with sands and marls. It has the following section:

 Section in Marl Pit, South Part of DeLand.
 Feet. Inches.
 Sand ................................................... 3 to 6
 Clay, red, sandy ........................................ 1 6
 Clay gray, sandy ....................................... 2
 Clay, gray, jointed ...................................... 8
 Shells .................................................. 3
 Clay, gray, brown ....................................... 1 6
 Shells .................................................. 10
 M arls .................................................. ?

 A sample of each of the two lower gray clays, which are separated by three inches of shells, was mixed in equal proportions and tested. The overburden over these clays is sufficiently great to preclude their having any commercial importance in-themselves, but as this material