White limestones of Sussex Co., JV. J. — Nason. 2 41 
which to my taste might be improved, but the author of a geolog- 
ical name, like the palaeontologist who describes a new fossil, is en- 
titled to priority. To attempt to introduce a new name for a group 
of rocks already sufficiently well designated, would only bring 
confusion, similar to that produced b}' the great variety of names 
implying correlation, that have already been used for the Newark 
system. 
THE POST ARCHAEAN AGE OF THE WHITE LIME- 
STONES OF SUSSEX CO., N.J.* 
Frank L. Nason, New Brunswick, N. J. 
I. 
Early in the year 1888, during the progress of my work on the 
Geological Survey of New Jersey, I was at Franklin Furnace for 
nearly two weeks. While there my attention was attracted by 
what I supposed to be boulders of gneiss in the white limestones. 
I also noticed the outcrop of sandstone, which appears on the 
north side of the Furnace pond. 
My curiosit} 7 was excited and farther search showed other local- 
ities as interesting as these. The result was that the idea of these 
white limestones being the metamorphosed "Blue" first suggested 
itself to me. I was then ignorant of the attention which this sub- 
ject had attracted iu the past, and supposed that I was the origi- 
nator of the idea. Further study showed me my error, but I 
determined to satisfj' myself on the subject, especially as it seemed 
to me that the question in whatever light it was regarded had 
never been fully settled. 
The first paper of consequence, bearing on this subject, appears 
in the ' ' Journal of the Academy of Natural Sciences of Philadel- 
phia," 1822. The authors, Keating and Vanuxem, have a paper 
on the ' ' Geology and Mineralogy of Franklin, in Sussex county, 
N. J." In this paper the writers offer no proof of the Archaean 
age of this limestone, though as will be seen, the idea is strongly 
*This paper deals only with the principal work that has been done in 
this area and a part of Warren county, and also a part of Orange county, 
N. Y. The full results of this work are recorded in the reports and 
papers quoted. 
The more recent work by the writer is published in the Annual Report 
of the State Geologist of N. J., for the year 1890. 
18 
