White Limestones of Sussex Countn } X. J. — JSTason. 161 
came less apparent, and coarse crystals of limestone, with scales 
of graphite, chondrocyte and other minerals, were abundantly 
developed. 
As nearly as possible, the outcrop was divided into bands 
corresponding to the degrees of metaniorphism and carefully 
Fig. 3. — Section through trench. 
I.— Unchanged blue limestone. II.— Prismatic slaty limestone, partly changed, with 
cloudy carbon. III.— Slaty limestone, very dense and compact; bright graphite scales, 
well crystallized. IV. — Coarse, graphitic (with slaty cleavage), chondroditic lime- 
stone, in contact with granite. V.— Granite. Distance from I to IV, forty feet. 
sampled (see fig. 3, i, u, m and iv). The results of these 
analyses, though not as conclusive as might be wished, not 
showing a gradual loss of magnesia, were as follows: 
l. 2. :i. 4. 
Insoluble 7.24 7.49 11.17 1.50 
Ca CO s 71.58 49.78 56.23 96.74 
Mg CO ;! 19.46 39.08 31.16 139 
Totals 98.28 96.35 98.56 99.63 
No. 1 here is the unchanged blue limestone. No. 4 the lime- 
stone in contact with the granite. 
Two things are to be especially noted in this connection. In 
the first place, though there is not a continuous outcrop from 
No. 8 bore hole to this point, a swamp intervening, yet at 
numerous places there are jagged points of limestone, north 
and south of this line and within two hundred feet of it. 
These points of rock were tested on fresh surfaces with hydro- 
chloric acid and none of them effervesced. It seems, there- 
fore, a tolerably safe conclusion to draw that a practically 
continuous outcrop across the strike of the rocks, from the 
Foot wall of the franklinite bed to a point where the white 
limestone grades into the blue, is, witli exceptions noted, a 
true dolomite, differing in no essential respect from the blue 
magnesian limestone. 
A second fact, strongly corroborative of the above, is that 
in the section in figure 3 is the blue limestone in which Obo- 
