THE MINING AND QUARRY INDUSTRY 



87 



tion in this vicinity has indicated a thickening of the ore to over 4 

 feet in places. At Clinton, Oneida co., the type locality, three beds 

 occur of which only the middle one has been exploited. The 

 highest from 4 to 6 feet thick is composed of pebbles and fossil 

 fragments coated with ferric oxid and cemented by calcite. It is 

 locally called red flux. The workable ore 2 feet thick lies 25 feet 

 below this and is separated by 2 feet of rock from the third bed 

 which is about 8 inches thick. The extension of the Clinton ore 

 to the east has been followed as far as Frankfort, Herkimer co.. 

 and Salt Springville, Otsego co. 



The hematite has a deep reddish color. It is solid and firm when 

 mined underground, but soft and friable in weathered outcrops. It 

 consists mostly of oolitic grains or concretions which have appa- 

 rently been deposited in rather shallow water. The grains often 

 inclose a kernel of quartz sand as a nucleus. The ore averages 

 high in phosphorus, but is well adapted for foundry iron. It assays 

 about 45 per cent. A considerable quantity of the ore is ground 

 for paint. 



5 The limonite deposits of Dutchess and Columbia counties are 

 a part of the great series of similar deposits that extend from Ver- 

 mont through Massachusetts, Connecticut, New York and south to 

 Alabama along the Appalachian uplift. There are two principal 

 ranges within the State: the one running northeast from Fishkill 

 in the valley of Fishkill creek, Dutchess co., and the other 

 farther east following the north and south valley, traversed by the 

 Harlem railroad, from the Highlands in Dutchess co. to Hillsdale. 

 Columbia co. The latter is the more important. The geologic for- 

 mations comprise Precambric gneisses and stratified quartzites, lime- 

 stones and schists. The quartzites lie immediately on the gneiss 

 and have been assigned to the Lower Cambric. The limestones and 

 schists are probably of Cambro-Ordovicic age. 



According to Smock the ore bodies are found in the limestone, or 

 between the limestone and the adjacent schist, or they lie within the 

 latter; as a rule they favor the contact of these formations. The 

 limonite forms small irregular pockets as well as large deposits, 

 and is associated with ochreous clay. Some carbonate ore is found 

 in the deeper workings, where it is interstratified with the limestone. 

 Its occurrence strongly suggests that the limonite has been formed 

 by oxidation and hydration of deposits of this ore. About 25 

 mines have been worked at different times. They are mostly open 

 pits, but occasionally drifts arc run from the bottoms of the pits 

 following the course of the ore body. The product is divided into 



