376 GEORGIA GROUP. 



at the trilobite locality is not so plain, but is sufficiently clear. Just above the layers 

 containing the fossils, there is a small bed of the red limerock interstratified with the 

 slates, and the great mass of the dolomitic rock is only a stone's throw distant. 



We would refer to the detailed description of the west end of Section VI. for the order 

 of rocks upon a section about eight miles north of the one in St. Albans. They are simi- 

 lar to each other ; the chief difference is the absence of the calcareous conglomerate from 

 the Georgia slate upon Section XI. This may be an accidental oversight, because it has 

 been seen only three miles north of the latter section. The alternations of the quartz 

 rock and conglomerate east of Georgia depot, are different from those in St. Albans. This 

 section passes through the trilobite locality. 



A word ought to be said about the relations of the Georgia slates to the Eolian lime- 

 stone. It will be necessary to suppose several singular disturbances of the strata in order 

 to account for their present relations. In some places the slates are above the limestones, 

 and in other localities the limestones are above the slates. The north end of the southern 

 deposit of Georgia slate seems to be interstratified with the Eolian limestone, by a gradual 

 passage of one into the other. Upon the supposition that there is an inverted fold, which 

 is doubtless the correct view, we cannot yet say from structural grounds alone whether 

 the limestone shall be considered as above or below the slates. 



The range of clay slate in Chittenden County lies east of Eolian limestone, and both 

 have the same general easterly dip. There is, however, a . singular feature respecting 

 the junction of these two formations. At Hubbcll's Falls, at Essex R. R. Junction, the 

 union of the slates and limestone is unobscured. Both rocks have a small dip away from 

 the line of junction, though the dip of the former is greatest, while at the junction itself 

 there are appearances of disturbance. The dip of the limestone is changed from 10 E. to 

 nearly 90 in a few yards ; and the strata of slate are nearly perpendicular also at the 

 junction, but in a few feet change to its normal inclination of about 40 E. These facts 

 indicate that there has been a slipping of one of these rocks above or below the other. 

 Considered without reference to theories, the limestone seems to be the rock which was 

 disturbed by the elevation of the slate. 



We have examined every mile of the line of contact of these two rocks between Milton 

 Falls and Starksboro, but find no case of actual junction except at Hubbell's Falls. The 

 nearest approaches to junction elsewhere are at Colchester depot and the north part of 

 Hinesburgh. Everywhere along the line the dip of the slates is uniformly greater than 

 that of the limestone. Upon an examination of the junction of the Franklin County de- 

 posit of Georgia slate and the Eolian limestone, it appears that both dip east at about the 

 same angle. The mode of their union has not yet received careful examination. Both 

 rocks dip east, and at Milton Falls they are both nearly perpendicular. 



The most plausible objection to the third view of the age of the Georgia slate arises 

 from the character of its fossils. According to eminent authority the trilobites belonging 

 to it correspond with those of Barrande's Primordial Zone of life, and therefore it is 

 claimed that the rock i of the age of the Potsdam sandstone. Upon this subject we shall 

 quote the opinions of eminent geologists, without attempting to decide between them. 

 The whole subject evidently needs further investigation. 



