418 A. Wings Discoveries in Vermont Geology. 



From the preceding account of Mr. Wing's discoveries it is evi- 

 dent that he performed well the task he laid down for himself 

 in 1865 — the determination of the age of the Eolian limestone. 

 Knowing that fossils were the only sure criterion of geological 

 age, he searched, and he found them, and thus reached sure concla- 

 sions. For the western portion of the Eolian limestone and more 

 i the eastern (that of Otter Creek Vallev), the special -»■<- 

 logical age was thus determined, and the several Lower Silurian 

 formation-; identified. He further made a right use of the facts, 

 when, in view of the Trenton and Chazy age of the fossils in linu- 

 stone along the borders of and within the " central slate-belt," and 

 the observation that the beds more remote are successively older- 

 he deduced that the slates were younger than the limestones 

 holding the Trenton fossils, and therefore, in all probabilitf, of 

 the Hudson River (or Cincinnati) group, and that they lay in a 

 synclinal wil r limestones beneath and 



side. 



The more' highly metamorphic condition of the li 

 ing the eastern border of the Eolian limestone prevented his giv- 

 ing to the geology of this part of the region the same positive 

 basis from fossils which he had obtained for the rest. 



The Quartzyte also proved almost barren, yielding him only 

 Scolithi and Mtcoids, neither of which serve to fix positively the 

 age of the beds. His argument with respect to it from the well- 

 defined Calciferous fossils found adjoining quartzyte at three dif- 

 ferent localities on the west and north is however a strong one, 

 and seems to set the question at rest for those outcrops. The 

 Vermont Geological Report states that the eastern Quartzyte 

 range, near Rockville in Starksboro, has afforded a Lingula— the 

 specimen containing "scores of fossils but none verv dirtinct"-— 

 which Prof. James Hall " regards as a new species related to one 

 in the Medina sandstone," and as evidence •• Though unsatisfac- 

 tory" that the quartzyte is of the age of the Medina. From the 

 irtzyte range farther so: li I Lake Dun- 



more, Prof. C. B. Adams, as it states, found a shell near a M»dh>- 

 &mmm ni form; also a tapering shell looking like an 

 let the determinations of all these fossils are admitted to be 

 doubtful, and the question of age is still an open one. 



One of the most important points established bv Mr. Winn is 

 the conformability of the Lower - throughout 



the region. From the Red Sand-rock, or Primordial, upward they 

 make one consecutive series, and all are involved. aOir. W im,' 



tie system of synclinals and anticlinals. The , 

 hydromica slates, and limestones, associated on the eastern border 

 of the region, and the great bands of limestone, hydromica slate 

 and clay slate (or roofing slate), with some quartzyte, making*the 

 I western portion, are of one system, and took, together, 

 their present positions. The great fault which made Snake 

 Mountain was simply one of the breaks and displacements at- 

 tending the mountain-making movement, as shown years since by 



