436 REPORT ON NATIONAL MTTRETIM, 1886. 



and a dark, almost black, variety at Weeliawken and West Kew York. 

 Other quarries of this rock are worked at Orange Mountain, Snake 

 Hill, Iludsou County, and at Morris Hill in Paterson. In the western 

 part of the State the outcrops are not so extensive, but quarries are 

 worked at Eocky Hill, near Titusville, Smith's Hill, and near Lambert- 

 ville. At Eock Church, 4 miles from Lambertville, the rock is quar- 

 ried and used for monumental work as well as for general building pur. 

 poses, being put upon the market under the name of black granite. The 

 rock from the Palisade quarries has also been quite extensively used 

 in and about Jersey City for building purposes. St. Patrick's Cathe- 

 dral, and the Hudson County Court House, as well as many private 

 buildings, are of this stone, but the effect as a whole is not pleasing, ow- 

 ing to the somber colors of the material. Employed in connection with 

 brick or lighter stone, to give variety and contrast, the effect is admir- 

 able. 



The finely broken stone is also used very extensively for railroad 

 ballast and road-making. Several of the quarries near Orange Mount- 

 ain have machines for breaking ui^ the stone for this purpose.* 



Pennsylvania, — The principal quarries of diabase in this State are at 

 Collins Station, Lancaster County, and near York Haven, York County. 

 At the latter place the face of the quarry is about 70 feet in height. 

 The rock lies in huge natural blocks sometimes weig-hing hundreds of 

 tons and having curved outlines giving them a sort of oval shape. 

 Stone from this quarry is used only by the Northern Central Eailroad 

 in the construction of bridges, culverts, etc. 



At Collins Station diabase is more extensively quarried than at any 

 other locality in the State. The stone is used for all manner of build- 

 ing purposes and monumental work. The foundation of the new Har- 

 risburg postoftice and the soldiers' monument in this city are from 

 this material. 



In the vicinity of Gettysburgh diabase has been quite extensively 

 quarried from bowlders, and has been used for head-stones in the na- 

 tional cemetery at this place. 



Virginia. — As in the States to the east and north, the Triassic beds 

 of Virginia are cut by large dikes of " trap " or diabase, and which in 

 some cases are capable of affording excellent material for leaving blocks 

 and general building and ornamental work. So far as the author is 

 aware quarries have been opened upon these dikes in but two localities, 

 at Cedar Eun, near Catlett's Station on the- Virginia Midland Eailroad, 

 and near Goose Creek, about 3 miles east of Leesburgh, in Loudoun 

 County. Specimens of these rocks which we have examined represent 

 the coarser varieties of our Mesozoic diabase, are of a dark gray color, 

 very strong, and apparently durable. That from Goose Creek has been 

 found to stand a j^ressure of 23,000 pounds per square inch, and, as the 

 author has observed, undergoes no change on an exposure ol' twenty- 



* See Anil. Rep. State Ocnloii-ist of New .lersey 18SI, pp. ()0-():>. 



