GUELPH FAUNA IN THE STATE OF NEW YORK 17 



Other manifestations in Orleans county 



In the townships of Barre and Clarendon lying between Shelby town- 

 ship and the west boundary of Monroe county, outcrops of the dolomites 

 are seldom shown. Except at Clarendon village almost the entire surface 

 of the dolomites has been planed down and forms the floor of the basin in 

 which lie detached northern parts of the Oak Orchard swamp. The lower 

 element of the series is exposed at several places near the northeast corner 

 of Barre. At Clarendon village the exposure shows the lowest layers (i, 

 of the Niagara section) in and above the falls ; in the ridge south of the 

 village strata 2 and 3 are exposed. No trace, however, of Guelph fossils 

 has appeared here. About 40 feet above the base of the dolomites 

 there appears a cherty layer, similar to, perhaps identical with that in 

 Niagara county; in the latter section the elevation of the layer above the 

 Rochester shale is 75 feet. 



One and one half miles east of Barre Center and on the ridge south 

 of Clarendon are found the rough layers appertaining to division 7 of the 

 Niagara section, and the more even grained, sandy dolomites which cap 

 the section near the rapids of the Niagara river, are quarried at Honest 

 Hill, 3 miles south of Clarendon. 



In all the section exposed at Clarendon no trace has been found of 

 Guelph fossils ; the lower Guelph fauna as expressed at Shelby is absent 

 and the horizon of the upper fauna is not clearly exposed. South of the 

 line of outcrop of these upper rough dolomites the country is dotted with 

 boulders of this origin, made rougher and more jagged by the action of 

 decomposing agencies. 



Monroe county 



Allen creek section. Directly south of Rochester, an interrupted sec- 

 tion of the dolomites is made by Allen creek, a stream of many branches, 

 traversing the town of Pittsford, flowing north and discharging into the 

 Irondequoit river, (i) The lowest exposure is beneath the large cul- 

 vert through which the stream passes under the New York Central Rail- 



