40 FLORIDA GEOLOGICAL SURVEY TENTH ANNUAL REPORT. 
In using the fullers earth strata it is frequently impossible to 
determine whether the exposure in question represents the upper 
or the lower of the two layers. However, as the total combined 
thickness of the two layers seldom exceeds about 15 feet, this dis- 
crepancy is not serious. The exposure at Rock Bluff indicates 
that there is in places at least as much as 90 feet of calcareous and 
phosphatic sands of this formation below the. fullers earth. On 
the other hand, at the pit of the Fullers Earth Company at Mid- 
way, may be seen as much as 25 feet of cross bedded and in places 
slightly calcareous sand of this formation above the fullers earth. 
Allowing 15 feet for the combined thickness of the fullers earth 
beds, the whole thickness of this formation is not less than 125 or 
130 feet, and may be considerably more. 
In the public road about r% miles southeast of River Junction is 
an exposure of fullers earth which may represent either the upper 
or the lower stratum of this horizon. A line of levels run from 
the bench mark at River Junction indicated for this exposure an 
elevation of 212 feet. At the abandoned mine on the S. A. L. 
Railway about 7 miles east of River Junction the fullers earth, up- 
per stratum, lies 1 77 feet above sea level. At Quincy 20 miles 
east of River Junction the top of the upper stratum of fullers earth 
is 145 feet above sea. Continuing this line, of levels, it is found 
that an exposure of fullers earth about 1 mile east of Little river 
is at the level of 120 feet above sea. At the fullers earth mine at 
Midway, the elevation of the top surface of the fullers earth is 112 
feet above sea. The dip of the formation in the direction of this 
line of levels which is slightly south of east from River Junction is 
about 100 feet in 25 miles or an average of approximately 4 feet 
per mile. From northwest to southeast, as measured from River 
Junction to Jackson Bluff, the dip in the formation is somewhat 
greater, approximating 5 y 2 feet per mile, or 137 feet in a distance 
of about 25 miles. 
At Attapulgus the fullers earth stratum lies 173 feet above 
sea. From this locality to Midway, a distance of about 19 miles, 
the dip in the formation is 59 feet. The average rate, of dip in this 
direction, which is approximately from north to south, is therefore 
about 3 feet per mile. Near Sopchoppy river, clays resembling the 
fullers earth lie in this formation at an elevation of 23 feet above 
tide water. If the line of elevation be extended from Attapulgus 
