﻿V 



2" 



l' 



4" 



6' 





5' 





4' 





22" 



-14" 



l6"-2 4 " 



4' 



6" 



3' 



2" 



84 NEW YORK STATE MUSEUM 



Sanford cut section 



Lowville 



Blue gray, oolitic limestone, full of lamellibranchs and with 

 Tetradium cellulosum 



Massive Tetradium beds, dove limestone full of crystalline calcite 



Thin bedded, blocky dove limestone; second zone of Bath- 

 yurus extans 



Irregular, thin bedded, blocky, dove limestone, more massive above, 

 culminating in a heavy, irregularly surfaced Stromatocerium 

 layer; holds B. extans below 



Thin bedded, f ossiliferous, dove limestone, with Camarotoe- 

 c h i a plena, fitting to uneven surface beneath 



Heavy, massive dove limestone, Tetradium and other 'fossils, 

 masses of Stromatocerium at surface, giving bunchy character 



Speckly dove limestone with shaly seams ; bryozoa, Tetra- 

 dium syringoporoides (Ulrich, ms) and other fossils 



Heavy, massive bed of gray, crystalline limestone, full of fossil 

 fragments at base, bryozoa and gastropods above; conglomer- 

 atic, many quartz grains, base of Lowville 

 1' 6" Shaly, dove, mud limestone, three beds; very fine, even grained, 

 cherty looking 



Leray and Watertown limestones. Emmons had already pointed 

 out that the Seven foot tier was closely connected by its lithologic 

 character with the underlying formation, and the writer had found, 

 while in preceding years collecting the cephalopods of the forma- 

 tion, that the characteristic cephalopods of the " Black River " 

 limestone for which the Watertown region is renowned among 

 paleontologists, viz, Gonioceras anceps, Hormoceras 

 tenuifilum, Lituites undatus and also the " Black 

 River " coral Columnaria Phalli (= C. alveolata 

 auct.) appear already below the Seven foot tier, 3 while at the same 

 time the characteristic fossils of the Lowville cited above, especially 

 also the omnipresent Tetradium cellulosum, disap- 

 peared. Since this faunistic extension downward of the " Black 

 River " is coupled with a greater lithologic similarity of the upper- 

 most 20 feet of the Lowville, as formerly conceived, with the " Black 

 River " than with the typical Lowville, and this upper portion of 

 the Lowville is characterized by seams of chert nodules which 

 make good horizon markers, we decided to draw the Lowville-Black 

 River line where Tetradium cellulosum abruptly disap- 

 pears and the chert layers begin. In mapping the " Black River " on 

 this basis, it was found that, on the whole, the cherty limestones also 

 exhibit the characteristic blocky weathering of the Watertown bed, 



1 While these cephalopods first appear in greater number in the cherty 

 beds just below the 7 foot tier, a few stragglers either identical or only 

 prenuncial mutations of them, have already been noticed in much earlier 

 horizons of the Lowville. Thus Hormoceras tenuifilum 

 and a large colony of Columnaria ? halli were noted 11 feet below 

 the cherty beds in a Tetradium bed in the section opposite the filter plant at 

 Watertown. 



