312 The Taconic Question Restated. [ April 
THE TACONIC QUESTION RESTATED. 
BY T. STERRY HUNT. 
(Concluded from page 250.) 
§ 29. It must be further noted that the term Taconic, unless 
qualified and limited as Upper Taconic, includes, besides this 
Cambrian, another and a not less important series of rocks which 
cannot be brought into parallelism with either Cambrian or Silu- 
rian, and is separated from the Upper Taconic by great lithologi- 
cal differences, as well as by stratigraphical relations and by 
geographical distribution. We have shown that Eaton long ago 
pointed out the well-marked stratigraphical discordance between 
the base of the First Graywacke and the Transition Argillite ; 
and it is also to be observed that the Lower Taconic, which con- 
sists of this Argillite (called by Emmons the Magnesian Slate, 
but including a band of roofing-slate), of the Primitive Lime- 
rock or Stockbridge limestone, and of the Primitive Quartz-rock 
or Granular Quartzite, is in many places wanting at the base of 
. the First Graywacke. Indeed, it is not recognized by its dis- 
tinctive characters along the western border of the Atlantic belt 
anywhere within the province of Quebec or in northern Ver- 
mont; where the Upper Taconic rests upon more ancient crystal- 
line hornblendic and chloritic rocks very unlike the Magnesian 
slate of Emmons, and where, moreover, neither the Primitive 
Lime-rock nor the Primitive Quartz-rock are known. 
That the green sandstones and conglomerates which make the 
basal beds of the Upper Taconic contain the ruins of these older 
crystalline rocks, was already noticed by Emmons, and is seen ` 
at many points, notably at Pistolet Bay, in Newfoundland, where 
a great body of these rocks, which were referred to the Sillery 
division of the Quebec group, rests directly upon a series of — 
hornblendic and chloritic rocks with serpentines. This imme- 
diate superposition of the Sillery sandstones to these crystalline 
schists was explained in Logan’s hypothesis by the double as- 
sumption that the green sandstone is the uppermost member of 
the so-called Quebec group and has escaped an imagined altera- 
tion, and that the immediately underlying crystalline rocks 
belong to the Lauzon or middle member of the same group, 
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