THE MINING AND QUARRY INDUSTRY I908 St, 



The sh'Cet of diabase forming the Pahsades and altogether in 

 New York and New Jersey, having an outcrop of some 70 miles 

 and a thickness of 300 to 800 feet, is the most valuable trap mass 

 in the State. Rockland and Richmond counties are the chief pro- 

 ducers. 



The chief use of trap at the present time is in the form of 

 crushed stone for use as a material in macadam road construction. 

 Its peculiar interlocking crystallization and the abundance of 

 pyroxene have given to the rock a very decided toughness, and, 

 since this property is accompanied by the quality of the separate 

 particles to bind into a firm mass after the road is constructed, the 

 pnatcrial has attained a well earned reputation as one of the best 

 road metals. 



The other in^porlant uses are in the form of crushed stone for 

 concrete construction and for railway ballast. As a building or 

 monumental stone diabase is of little importance. In the first place 

 its toughness makes it an extremely expensive stone to quarry and 

 to dress, and then too its somber hue is generally objectionable, 

 although in monumental work the contrast between the hammered 

 and polished surface is a pleasing feature. 



The production of trap in 1908 was confined to the dike near 

 Greenfield, Saratoga co., where considerable road metal was taken 

 out, and to the Rockland county quarries at Haverstraw, Nyack, 

 Mt Joy and Rockland Lake. The crushing plant of the Quinroy 

 Construction Co. at Port Richmond, Richmond co. was destroyed 

 by fire in March 1908 and no output was made. They will probably 

 rebuild their plant during the coming season. 



Owing to the general decrease in construction work during 1908, 

 because of business depression, the output of trap rock fell below 

 ihat of 1907, the total value in 1908 being $723,773 as against 

 $941,627 in 1907. About 81 per cent of the production was sold 

 for macadamizing roads and the remainder used for concrete con- 

 struction and railway ballast. 



