HOVEY: ARTESIAN WELL AT KEY WEST. 71 
Above 700. feet the material was so comminuted, probably by the drill, 
that it seems impracticable to differentiate the Miocene and Pliocene 
beds. The surface očlite ceases between the depths of 25 and 50 feet, 
which may indicate that the top of tho Tertiary is there. Furthermore, 
it seems that the marked change in the appearance of the beds between 
375 and 400 feet from tho surface must be of some significance. 
The following notes on the samples of the borings from the Artesian 
well at Key West will give an idea of the condition and composition of 
the material examined. 
SURFACE. — Color yellowish white. The surface rock consists of an odlitic 
limestone which pulverizes with comparative ease between the fingers. The 
nuclei of the ovules are for the most part rounded or subaugular calcareous 
grains, but one ovule was observed which was built up around a grain of 
quartz. The matrix consists of minutely comminuted stuff. No fragments of 
either shells or coral were observed. The rock left the merest trace of quartz 
sand behind on treatment with HCl, like that which is fully described under 
the material from 250 feet and deeper. 
25 feet. — Color yellowish white. Oólite; like the above, apparently, though 
the sample consisted of nothing but the ovules. Not even a trace of the quartz 
sand noted. After a time a floceulent brownish white precipitate settled out of 
the HCl solution. A flocculent precipitate like this, but varying in color to a 
greenish black, was obtained with almost all the samples. See Analysis, p. 85. 
50 feet, — Color white with yellowish and brownish portions. A compact, 
somewhat sparry limestone filled with fragments of foraminifera, corals, re- 
mains of echini, lamellibranchs, gastropods, ete. Crystals of calcite are present, 
as is true of many of the other samples. The rock contains vast numbers of 
foraminifera and other calcareous micro-organisms. No quartz sand, appar- 
ently. The rock is oólitie, but is not friable like the two preceding. It is 
mainly a shell limestone with much oólite and foraminiferal rock. 
75 feet. — Color gray-white. A compact limestone containing pieces of 
coral and porous lumps. Under the microscope the rock is seen to contain 
fragments of shells and coral in a fine granular base in which are some forami- 
nifera, There is a very small amount of limpid quartz sand present and а 
heavy gray-white floeculent precipitate settles out from the HCI solution 
after a little time, 
100 feet. — Color white. Compact limestone containing abundant remains 
of corals and shells, pectinoids, and other lamellibranchs. Some of the shell 
fragments are іп a matrix of oblite. Very, very small amount of quartz sand. 
Much of the flocculent precipitate in ПО, The lamellibranchs predominate 
among the determinable remains. 
