168 H. p. CUSIIIXG PALEOZOIC IX XORTHWESTERX NEW YORK 



fauna, though it is possible that the horizon may be the lower Lowville. 

 Identification of the ostracods would settle the question : 



"Two miles above Port Leyden is a railroad cut through a rock which corre- 

 sponds to the Calciferous in horizon. This rock is thick bedded in the tipper 

 part and is generally tinged with a pinkish color. The probable line of de- 

 marcation between this and the Birdseye limestone is a baud of friable sand- 

 stone of a dingy color."' 



Port Leyden is some 4-5 miles up tlie river from Carthage, the direc- 

 tion about south-southeast. The interval is so great that correlations 

 are unsafe, but the description recalls at once the pinkish beds of the 

 upper Pamelia and the similar beds underneath the Lowville in Canada. 



Between Port Leyden and Carthage, Sarle notes several localities 

 Avhere the "'Calciferous" is exposed and three where the underlying '^'Pots- 

 dam" is seen. On Eoaring creek, near Martinsburg (just south of Low- 

 ville and midway between Port Leyden and Carthage), he notes a con- 

 tinuous section down to the gneiss and estimates thickness as follows: 

 Black Eiver limestone, 10 feet ; Lowville, 40 to 45 feet : Calciferous, 20 

 feet, and Potsdam sandstone, 4 feet. The latter is dark red and has a 

 calcareous cement. 



In his paper Sarle's estimates of thickness are generally underesti- 

 mates. If the thiclcaess of the Lowville as given is accurate, then the 

 added thickness of the underlying "Calciferous" and "Potsdam" gives 

 a total thickness which is quite comparable with tlie thickness of the 

 Lowville in the Theresa section; but if this thickness is rmderesti mated, 

 it is most probable that his underlying beds really represent the thiimed 

 edge of the Pamelia formation. Unless the Lowville changes much in 

 character in the interval between Lo-\^-ville and AVatertown. no one would 

 ever think of calling any of it "Calciferous," even though expecting to 

 find that formation underneath the Lowville. whereas much of the Pa- 

 melia is lithologically quite like much of the Beekmantown. If the 

 Pamelia be present, it has unquestionably a thickness of but a few feet, 

 so that its basal sandstone has risen in horizon nearly to the base of the 

 Lowville. The formation has, however, thinned to 50 feet on the eastern 

 margin of the Theresa quadrangle. 



The fact that for so many miles along the Black river, namely, from 

 Carthage to Port Leyden, the section seems substantially the same, the 

 ftiU thickness of the Lowville. with a few feet of possible Pamelia be- 

 neath, and then the basal sandstone, would seem to indicate that the 

 valley here follows closely the trend of the old shoreline of the Pamelia 

 sea, and that, if Sarle's estimate be correct, we have a thickness of some 

 25 feet of the Pamelia formation along it. At right angles to this line 



