No. 3. — Notes on the Artesian Well Sunk at Key West, Florida, 
in 1895. Ву Ермохр Org Hovey. 
IN 1895 an Artesian well was sunk at Key West, Florida, to the depth 
of 2,000 feet. Samples of the borings were taken every 25 feet from 
the surface to the bottom, and through the kindness of Mr. Alexander 
Agassiz a set of these samples was placed in my hands for microscopic 
examination. The petrography of the material passed through is simple. 
It is all an almost perfectly pure lime-rock, and is a typical oólite at the 
surface and at 25 feet below. Beneath that depth most of the samples 
indicate a fine or coarse, more or less loosely compacted sand-rock, 
relieved somewhat by beds or masses of compaot limestone or porous 
rock, Small bits of: oólite, or loose ovules, are present in about half of 
the samples, indicating a shallow water origin for much of the material. 
The most solid rock of all passed through seems to come from the depth 
of DO to 175 feet from the surface, inclusive. 
Perhaps the most peculiar petrographic feature is the presence in all 
the samples except three (25, 50, 1,375 feet) of a small amount of 
quartz. This varies from the merest trace up to a very noticeable pro- 
portion, and is sometimes visible under a one-inch hand lens. About 
two grams of each sample was carefully dissolved in hydrochloric acid, and 
the residue washed and examined under a compound microscope. This 
residue consisted mostly of a very fine-grained angular sand, having 
the lustre and fracture of quartz, and scratching glass with ease. Some 
of the grains suggested the hexagonal outlines and pyramidal termina- 
tion of crystals, but none was definitely made out. The particles were 
perfeetly limpid and showed no effects of abrasion. With this angular 
sand were sometimes associated a few well rounded grains of clear 
quartz of mueh larger size. Frequently the rounded grains were too 
coarse to pass through a No. 40 mesh sieve, but this was never the case 
with the angular material. It seems probable that the fine grained, 
angular quartz is of secondary origin by infiltration of siliceous waters. 
That the waters percolating through the rock strata of Florida carry 
silica in solution, is clearly indicated by the chaleedonized Miocene 
VOL. XXVIII. — NO. 8. 
