White Limestones of Sussex County, A". J.—Nason. 155 
parallel bed of magnetite, from a few inches to two or 'three 
feet in thickness. The magnetite lies between the gneiss and 
the limestone foot wall of the franklinite bed. From this font 
wall bed two samples of limestone were taken, covering a dis- 
tance of about one thousand feet along the line of strike. 
None of the samples collected effervesced with cold hydro- 
chloric acid. 
Fig. 1.— Outcrop of the Mine hill ore body. 
l-2.-Magnesian limestone, foot wall of mine. 3.-Point where the back vein goes 
under gmunT 3-No. s.-Position of hack vein under ground Nos 1 5,6 and 8.- 
OiWond drill holes. 4->..-Position of section, Fig. 2, shatt 400 toot deep. 3-o-&- 
Outcrop of ore body. 
Through the kindness of Prof. Smock, state geologist of 
New Jersey, these samples were analyzed under the super- 
vision of Prof. A. H. Chester, official chemist of the survey. 
The analyses are as follows: 
I. II. 
Insoluble °- 58 5 - 75 
Fe 2 3 +A1 2 3 1-81 1-80 
CaCO, 62.96 51.12 
Mg CCV 3194 40 - 58 
Totals 97.32 99.19 
These analyses show that on the surface at least there is an 
outcrop of white magnesian Limestone, which is nearly a typi- 
cal dolomite. During the month of August. L893, some ex- 
ploring work in the Trotter mine was done with a diamond 
drill, for the purpose of determining whether or not any 
lenses of ore had been left either in the foot or the hanging 
wall of the mine. The drill holes were bored ;.t the four 
hundred foot level. Through the courtesy of Mr. J. A. Van 
