162 The America)) (reologist. Marcli, 189') 
non-conformity that vSeparates the Taconit- fioni the Archean 
have not been identified with eertaint}^ and that whatever 
may be the horizon at wiiieh such contacts happen to be ob- 
served, thej' can be considered the base onl}^ for those several 
points of observation. That tlu- confornial)]e strata of the 
Taconic extend for many liundred feet, if not tliousands of 
feet, below the zone with Olenellus is well authenticated in 
America. In Newfoundland, accordin<j!; to Mr. Howie}'', tiie 
present Government geologist, and in the opinion of Mr. Mur- 
ra}'' earlier, tlie Signal Hill quartzyte, and the under]3nng 
slates witii Asj>/(/c//(i are not separable from the strata carry- 
ing Olenellus, thougli tiie Olenellus strata are much higher in 
the formation. Not including the Signal Hill beds, there is 
still a thickness of 1,800 feet below the Manuel's brook con- 
glomerate containing Olenellus. In New Brunswick, accord- 
ing to Matthew, the Etcheminian series, reaching a thickness 
of 1,200 feet, lies below the St. John group ])roper, the base 
of wliich is thought to be at the Oleiu^llus zone, and is hardly 
separable from the St. John group. Lately Mr. AValcott has 
reported the existence of a great thickness of conformable 
clastic strata below the Olenellus zone in the eastern slopes of 
the Appalachians, from Vermont to Alabama.^'' 
If then we accept the great structural break which seems 
to be of wide extension in America, I'eferred to above, as a 
datum from which to reckr)n the continuance of Taconic time, 
which would also be in accord with tlie views of Irving on 
the significance of non-conformities, the Taconic system woidd 
have a definite basal plane determined by the physical history 
of the earth, M-hich has alwaj^s been the governing element in 
the great faunal (dianges of geology. 
THE SECOND LAKE ALGONQUIN. 
Hy Frank lUksi.i^Y I'avlor, Fort Wayne, liid. 
( Concluded. I 
Tht Anili(<lc of fhc Deformed J'lave. The remarkable uni- 
formity of the main Nipissing plane tloes not appear to ex- 
tend far toward the east from Sault Ste. Marie. For, as already 
stated, its projection in that direction passes about 40 feet 
below the Nipissing beach at North Bay. Its position seems 
*Vax HisK. Correlation P.-ii.iTs: J'.iill. S(i. p. Ki;). 
