164 
FLORIDA SFATF GEOLOGICAL SURVEY. 
Going down the river from Kings Ferry no rock or shell ex¬ 
posures are seen until Reeds Bluff, near Crandall, is reached. 
This bluff, which lies on the Florida side of the St. Mary’s River, 
is semi-circular in shape and is about three-fourths of a mile long. 
The following section was made near the middle of this bluff: 
Feet. 
Incoherent pale yellow sands. 20-40 
Oyster shell reef imbedded in fine, sandy clay. 10-15 
Blue sands and sandy clays oxidizing yellow. 10-20 
The oyster reef in this section rests irregularly upon the un¬ 
derlying sands, the base of the reef being- 10 to 20 feet above 
low tide. The oyster reef extends about two hundred feet along 
the face of the bluff. 
The unusual thickness of the loose yellow sands at the top of 
the bluff is due to the fact that the upward moving currents of 
air carry sand as it is loosened along the face of the bluff to the 
top, where it accumulates as a sand dune. 
Roses Bluff, also on the Florida side of the river, about two 
miles below Crandall, is semi-circular in shape and is fully two 
miles long. The following section was made near the middle of 
this bluff: 
Feet. 
Dark colored sand and soil. 4 
Dark iron-stained sand (hardpan). 7 
Ochre yellow sand. 8 
Sand with some clay. 5 
Sandy shell bearing marl, blue, oxidizing yellow. 4 
Sloping to water’s edge at low tide. 5 
33 
AREA OF ARTESIAN FLOW IN NASSAU COUNTY. 
That part of Nassau County in which flowing wells can be 
obtained is indicated on the accompanying map by shading. 
Flowing wells may be obtained as shown by the map, Fig. 6, 
in approximately the eastern twc-thirds of the county. A rela¬ 
tively small area, including the ridge already mentioned, lying 
near the western part of the county and extending north and 
south, parallel with the St. Marys River, stands too high to obtain 
