AND THE REPORT ON THE GEOLOGY OF VERMONT. 113 



line ongfht to be drawn farther west, in order to embrace the first line of Potsdam sand- 

 stone in the Georgia division. Cnrionsly enough, in my map, tliat knol;) is marked as 

 a lenticnlar mass, limited, north and sonth of Parker's honse, to about one thousand feet 

 in length. Also on the same map, the two other Potsdam sandstone lenticular masses 

 on the same line as Parker's house, ought to be included in tlie Georgia slates, as they 

 belong to them according to Mr. Walcott's observations. 



However, for the present, I am not inclined to accept the first three numbers of AVal- 

 cott's section, as belonging to the Georgia group, and also I do not admit their sup- 

 jiosed overlapping fault on the slates, near the lake shore. I shall discuss thsee points 

 farther on, wishing to finish the description and comparison of the two sections. 



The Parker's quarry forms a steep cliff, fifty feet high at the highest point. The sec- 

 tion and desci'iption I liavc given in 18G1 and 1880 are still the only ones and they have 

 not been contested, excei)t on the dip of the strata, which Mr. "Walcott gives as only 12" 

 east in his text, and in his section, p. 16, they are drawn at an angle of 35° and even 40", 

 agreeing then with the inclination of 35" given in my sections and memoirs. 



Between Parker's quarry and the westward limestone lenticular mass, there is a small 

 valley, quite open, less than fifty yards broad, formed by slates, on which rests a sort 

 of lentille of blue limestone, containing two Trenton fossils (Brachiopod and Coral) . The 

 block is only one foot and a half square; it seems to have been rolled, and I have re- 

 garded it as a boulder. Mr. Walcott is of the same opinion. However, I have some 

 doubts now as to its being a boulder; possibly it may be a colon}^ 



Advancing eastward, above the Parker's quariy, there are slates forming a platform 

 and then a declivity. Directly north we find the end of a lenticidar mass of magnesian 

 limestone containing Bracliiopoda, about twenty feet thick, and extending from the top 

 of the hill to the road from St. Albans' bay to Parker's farm. Their dip is 15" or IG" east. 

 The slates in front of the limestone, on the declivity, seem to dip at 30° and 35", but 

 some cleavage may exist there; and it will be better to have new observations made be- 

 fore giving a definite dip. 



Colon]!- — At about only twelve or twenty feet from the limestone lentille, are found 

 several isolated slabs or flag-stone, lying on the slates, in concordance of strati lication. 

 Almost one foot thick, three or foiu* feet in length, with sharp angles, they consist of a 

 sort of blue limestone containing two or three fossils of the second fauna. From their 

 position and peculiar forms, which will not admit transportation by a glacier, I regard 

 them as surely a colony of the second fauna inclosed in the Georgia slates. In the walls 

 near the house of Mr. Parker, some loose pieces of blue limestone, containing one or two 

 Trenton fossils, have been seen. It is impossible to say whether they come from a boul- 

 der or from a colony near by. I have no doubt that other colonies will be found among 

 the Georgia slates, not only in the Lake Champlain region and in Canada, but also all 

 along in southern Vermont, in eastern K"ew York, and in western Massachusetts. 



My section fig. 2 ends a little northeast of Parker's house. I do not see any change 

 to introduce in my former section of 1880, eastward from Parker's to the Green Moun- 

 tains. Mr. Walcott has found a fault between Georgia Village or Centre and the Ver- 

 mont Central i-ailroad, and has stopped short with a blank at the foot of the first Green 

 Mountain hill. 



MEMOIKS BOSTON SOC. NAT. HIST., VOI,. IV. 17 



