436 REPORT ON NATIONAL MUSEUM, 1886. 



and a dark, almost black, variety at Weehawken and West New York. 

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

 Dill, Hudson 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 Rocky Hill, near Titusville, Smith's Hill, and near Lambert- 

 ville. At Rock 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 up 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 weighing 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 Railroad 

 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 post-office and the soldiers' monument in this city are from 

 this material. 



In the vicinity of Getty sburgh 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 paving 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 Run, near Catlett's Station on the Virginia Midland Railroad, 

 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 pressure of 23,000 pounds per square inch, and, as the 

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



* See Ami. Rep. State Geologist of New Jersey 1881, pp. 60-6;}. 



