38 Geology of Tampa Bay, Florida. 
Art. IV.—Some facts respecting the Geology of Tampa Bay, 
Florida ; by Joun H. Auten, Principal of Chilicothe Acade- 
my, Ohio, and late Lieut. of Artillery in the U. 8. Army in 
Florida. 
Tue peninsula of Florida presents many interesting geological 
features ; it is evidently of an origin comparatively recent, and its 
‘ rocks and marl beds are replete with a vast quantity and rich va- 
riety of organic remains, which have as yet been but imperfectly 
examined. This region is not only attractive to the geologist, 
but to the naturalist in every department. Along the borders of 
its rivers and in its rich hammock lands, are found a profu- 
sion and variety of trees, shrubs and baiits; which excite ad- 
miration by their magnificence and beauty. It swarms with 
beautiful insects of every hue; and in the shallow waters of its 
bays live myriads of shell Ssh, belonging to a great — of 
species. 
One of the most interesting points in Florida to the geologist 
is the neighborhood of Fort Brooke at the head of Tampa Bay: 
The first layer of solid rock beneath the soil is a stratum of lime-. 
stone ; it is hard and white, has an earthy texture, and appears to 
have resulted from comminuted and decomposed shells. The 
surface of this rock is exposed in several places in the vicinity of 
Fort Brooke, about two miles north, near the Hillsboro’ river, four 
miles west on the shore of the bay; and six or seven miles east 
in the banks of a small stream. This rock has a very extensive 
range. Ihave seen it in many parts of the territory ;—in some 
places it is soft and friable, very much resembling chalk, all traces 
of organic remains having been obliterated by the decomposition 
of its material previously to its consolidation. I have noticed it 
at points more than one hundred and fifty miles distant from each 
other, presenting the same lithological characters. It constitutes 
the bottom of the many ponds and lakes in the interior, and I 
have been informed, that its white and jagged surface can be seen 
throughout the whole extent of the everglades, that singular sea 
of fresh water and coarse grass, that covers an area of - 
) | square miles in the southern part of the peninsula. ‘This 
