﻿GEOLOGY OF THOUSAND ISLANDS REGION 75 



Both these sections are imperfect in their showing of the beds 

 of the extreme summit. The most excellent section shown in the 

 railway cuts just south of Sanford Corners (southeastern part of 

 Theresa quadrangle) supplies this deficiency [pi. 18]. 



i' 4" Two 8" layers of blue gray, crystalline limestone, abundant lamelli- 



branch casts full of crystalline calcite; dove limestone mud balls 



1' Mud cracked, argillaceous, somewhat granular, bluish limestone, 



weathering yeliowish 

 1' Thin bedded, blue, granular limestone, conglomeratic, quite shaly 



below, very fossililerous, chiefly bryozoa; base of Lowville 

 11" Dove gray, fine, impure limestone, weathering light 

 3' 2" Laminated, mud cracked, gray dove, argillaceous limestone, thin 



bedded, ripple-marked, worm-burrowed 

 1' 9" A 6" layer below and an upper 15" bed; fine dove limestone with 



calcite spots, gastropods and cephalopods 

 1' 10" Gray, granular limestone, crystalline specks and spots; shaly 



below, more massive above 

 5' 6" Finely granular, blue dove limestone, shaly below, more solid 

 above; blocky weathering; calcite seams and spots; sparse 

 Phytopsis in upper part 

 4' 6" Mottled, blue dove limestone, thin bedded above and below; 

 much crystalline calcite replacing poorly preserved fossils 

 8" Blue black, finely granular, dove limestone; calcite spots 

 l' 10" Blue gray, calcareous, sandy shales, weathering yellowish 

 7" Dark blue, finely crystalline limestone; conglomeratic 

 8" Blue gray, calcareous shales, weathering yellowish; sand grains 

 8" Blue dove limestone; base weathering sandy looking 

 9" Sandy, argillaceous, shaly limestone, weathering yellowish 

 9" Blue dove, mottled limestone 

 3' 1" Gray blue, dove limestone, somewhat muddy, shaly fracture 



7" Blue dove limestone, small limestone pebbles 

 1' 9" Solid layer of blue dove limestone, rudely laminated with or- 

 ganic streaks 

 1' 10" Laminated, argillaceous, fine grained, mottled, blue dove lime- 

 stone; two seams 

 1' 4" Fine, flinty, dove limestone; slightly conglomeratic at base 

 1' 10" Fine, flinty, dove limestone, with a shaly streak of 3" ; lower 



portion with Phytopsis 

 4' Rather compact, fine dove limestone; a little Phytopsis in the 



upper 3" 

 1' 2" Blue dove, thin and irregular bedded limestone 

 2' 6" Measures concealed 



5" Blue dove, mottled, laminated limestone, small ostracods 



45' 5" Of which the lower 41' 8" belongs to the Pamelia 



The 1 foot layer, third from the top of the section, is divisible into 

 an upper 3 inch portion, full of fossils, making an irregular contact 

 with the remainder, which lacks fossils, and in Uirich's judgment, 

 with which we coincide, the line between the two formations is 

 properly drawn at that slight break. These upper dove limestone 

 layers, over 40 feet thick in this section, have puzzled us much and 

 have been difficult to classify. They are above the white, earthy 

 beds which are the most characteristic lithologic feature of the 

 upper Pamelia, and while they are precisely like the dove limestones 



