20 NEW YORK STATE MUSEUM 



depression into the front of the old Hoyt limestone quarry — a 

 spot of historic interest in New York geology for from it the name 

 of the geologic formation itself — Hoyt limestone — is derived. 



It is the purpose to provide this " Lester Park " with explanatory 

 placards which will make clear its lesson and its interest, and to take 

 such measures as may present the geological display here in its 

 greatest effectiveness. 



stark's knob 



At the north end of the Saratoga battlefield, 2 miles above 

 Schuylerville and close to the highway, stands Stark's Knob, a once 

 dome-shaped volcanic knoll on which, on that memorable and de- 

 cisive field, General John Stark mounted his battery and effectively 

 obstructed the attempts of the defeated Burgoyne to withdraw his 

 forces northward through the narrow valleys of the Hudson and 

 the Battenkilh It is an historic spot. But its geology is of more 

 singular interest. Some years ago its owner leased the knoll to a 

 company that cut into its eastern face to obtain the rock for road 

 metal. Fortunately for geological science the rock, though volcanic, 

 has proved unsuitable for good road construction. The exposure of 

 its substance attracted the attention of our geologists and it became 

 evident that the rock was not merely of volcanic origin but was the 

 actual remains of a single volcanic plug or neck. There is no 

 other volcano in New York. But not this fact alone answered the 

 inquiries of the geologist. It was found that the lava plug lay in 

 between the masses or layers of the Hudson River shale, that its 

 prominence in the landscape was due to the erosion of the shale 

 from about it, but where the lava came from, whether it came up 

 through this ancient early Siluric shale here, a time at which we 

 know of no volcanic activity in this part of the country, or whether 

 it was of later date, were questions which perhaps are not even yet 

 determined but which nevertheless have called for many examina- 

 tions and conferences of geologists at the spot, many diagnoses of 

 the case after close examination of all the conditions in which the 

 volcano is involved. Geologists who can speak from most intimate 

 acquaintance of the rock and its surroundings are disposed to be- 

 lieve that this volcanic plug did not come up through the rocks at 

 this place. The country is one of great disturbance in its rock 

 structure. It lies in the heart of mountain folds of an ancient type 

 and right here these overturned mountain folds with their thrust 

 faults or planes along which the top of the fold has been 

 shoved over their lower part are very clearly manifested. The 



