Great Synclinal in the Taconic Range. 275 
corals and ecrinoids. This fact, paralleled with that of the 
occurrence of similar mountain-synclinals and Lower Silurian 
fossils in the Taconic regi rmont, affords paleonto- 
logical evidence of the Lower Silurian age of the limestone of 
the ashington part of the Taconic region; and, since 
group), they make, as has been stated, the schist of the 
mountain to be that of the Upper Llandeilo flags or Hudson 
River group. 
4. Since the schist of the mountain is not older than the 
Llandeilo flags, or the upper beds of the Lower Silurian, it fol- 
lows that not only roofing slate, hydromica schist, and chloritic 
hydromica schist, but also coarse mica schists, garnetiferous 
and staurolitic, have been crystallized at as eriod in 
geological history as the close of the Lower Silurian. 
5. These crystalline rocks were crystallized and rendered 
the ocean had taken place, since air is needed, as well as water, 
for such oxidation. In view of the occurrence of limestones of 
the later Upper Silurian (Lower Helderberg group) overlying 
the upturned Lower Silurian and Cambrian slates of eastern 
New York near Hudson in Becraft’s mountain and Mount Bob, 
and looking as if portions of a once extensive Upper Silurian 
formation covering much of New York State east of the Hud- 
son River, it is probable that the emergence of the rocks from 
the ocean just referred to did not take place before the end of 
the Upper Silurian. : 
The conclusions I have presented as regards the synclinal 
character of Mount Washington and the rest of the Taconic 
* [Full credit to earlier and later authors who have published essentially 
Same view as to the stratigraphy, I have given in former papers, the 
Paper in the Journal of the Geological Society of London for 1882.] 
Am. Jour. Scr.—Tuep Series, Vou. XXVIII, No. 166.—Ooroper, 1894. 
18 
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