1(50 IVie American Geoloijist. March, 1895 
and crystallized certain limestones, quartzytes and schists, of- 
ten involvin<>' isolated masses and se[)aratin<i,' them from their 
parent strata. 
There is in none of these cases, so far as known, any erup- 
tive older series, or volcanic breccia, on which the basal 
(piartzyte of the Taconic has been found to I'est, but. when- 
ever the basal contact on the oldei' rocks has been found, the 
older rocks are ^'neissose or j^'ranitic. The igneous rocks at 
this horizon on the other hand seem to have been of some date 
hiter than the commencement of the Taconic, and either by 
general fracturing of the whole foi-niation involved them in 
tumultuous confusion, or to have been interjected between 
their strata after the strata were formed. This statement is 
not intended to deny the existence of older igneous rocks, or 
even volcanic l)reccia, in the Archean, on which the Taconic 
may rest in other places, for it is well known that such exist 
and that the Taconic might lie on them. It might i)e truly 
said also, that so far as yet discovered the basal beds of 
the Taconic, when fragmental, have not been found in eastern 
New York and New England to consist of volcaiuc materials. 
That such may yet he discovered is ([uite evident, not only 
from the occurrence of such strata in the base of the Lower 
CUimbrian in south AVales, but from the existence of such ma- 
terials in great (piantities in the midst of the strata of the 
Penokee range in Wisconsin, which are believed to be of the 
age of the Taconic, as will appear later. 
Further south, in the region of the South mountain, one of 
the parts of the Alleghany mountains in Pennsylvania and 
Maryland, Mr. Walcott has reported the tinding of the Ole- 
nellus fauna in certain (piartzytes that are supposed to overlie 
volcanic rocks. The relations here are confused by faidting 
and folding,* and very different interpretations have been 
put on these rocks. To say the least, this position for these 
volcanics is not proven, the appearances indicating a very low- 
place interstratitied and intruded in the basal portions of the 
Taconic. As Dr. AVillianis remarks: "It may, however, be 
regarded as'an open cjuestion whether the volcanic rocks rep- 
resent a much older horizon * * * or whether they were 
*C. D. Walcott hihI (i. H. Williams. Am. .lour. Sci. (:{) xliv. i)p. 
4()9-4y(), 181)'2. 
