168 
FLORIDA STATE; GEOLOGICAL SURVEY. 
for this reason the views of some of the authors who have discussed 
the subject will be outlined below. 
Such a Pleistocene elevation as has sometimes been advocated 
would have united Florida with the island of Cuba, but in the course 
of his investigations of the geology of Cuba, Hill 1 found no evidence 
of there ever having been such a land connection between the island 
and Florida. Moreover, the Island of Cuba, according to this author, 2 
since the beginning of the Pleistocene has undergone comparatively 
slight changes of level. It is also worthy of note that the geology of 
Cuba indicates that its history has been very unlike that of Florida. 
A factor bearing on the question of an extensive emergence of 
Florida has been presented by Shaler, 3 who called attention to the 
fact that though the sediments of northern Florida and the adjacent 
States are marine they have been drained of their original content of 
salt water to a depth of nearly a thousand feet. In a later paper 
Shaler repeats the statement given above as evidence of recent ex¬ 
tensive emergence of the peninsula of Florida, and also calls attention 
to the large submarine springs off the coast. He considers that these 
facts together with the estuariene character of the lower portions of 
the stream valleys indicate a subsidence of the land since the extensive 
uplift. That both emergence and subsequent submergence have taken 
place since the late Pliocene will scarcely be questioned. The only 
point in dispute is the magnitude of the movement. 
The best known of the submarine springs is situated near St. Au¬ 
gustine. According to Captain E. C. Allen, of that city, the orifice 
of the spring is about sixty feet across and the depth is about 200 feet. 
The depth of the sea at the point of emergence is said to be about 
fifty feet and the water emerges with enough force to cause a distinct 
convexity of the surface during calm weather. According to some 
authorities, it is difficult to row a small boat across the surface above 
the spring on account of the outward movement of the water from 
above the orifice. 
There is no doubt that the marine strata of Florida contained salt 
water at the time of their deposition, and there is good evidence that 
the beds beneath the central part of the State have been drained of this 
water to a depth of several hundred feet. Owing to the fact that the 
deep wells have seldom been cased more than 200 to 300 feet it is 
1 Hill, Robert T. Notes on the Geology of Cuba, based upon a reconnaissance 
made for Alexander Agassiz, Harvard Coll. Mus. Comp. Zool., vol. xvi, No. 15, 
p. 285. 
2 Ibid., pp. 243-288. 
3 Shaler, N. S. Note on the value of the Saliferous deposits as evidence of 
former climatic conditions, Boston Soc. Nat. Hist. Proc., vol. xxiv, 1888-1890, 
p. 584. 
