T. C. Brown — Shawangunk Conglomerate. 469 



The High Falls shale is more variable in thickness as well as 

 in color and physical character in the various drill holes. The 

 larger values given above, that is 90 to 100 feet, more nearly 

 agree with the thickness exposed in the gorge. 



The Shawangunk conglomerate probably does not exceed 

 280 feet in thickness within this limited area. Where the 

 measured thickness is greater than this it has been affected by 

 folding or faulting, as is shown on the accompanying diagram 

 (fig. 2). 



These measurements, made in core borings and checked by 

 accurate measurements in the shafts during construction, and 

 by a comparison with the beds exposed in the gorge below the 

 falls, differ materially from those given by Mather and by 

 Darton. Their measurements are introduced here for com- 

 parison : 



Average section Mather's section Darton's section 



No. 



Cement beds ..(3 Cement rock 6- 8 Cement .. -. 



Binnewater sand- 4 Pyritous slaty Clinton to Medina 40 



stone 55j limestone, 4-10 



High Falls shale. 90J5 Red shale.. 15-20 

 Shawangunk con- 6 Conglomev- 



glomerate 27ol ate.. jShawangunk .. 



In a cut on the Wallkill Valley railroad near Binnewater 

 the full section between the cement beds and the Hudson 

 River shale is exposed. This section gave the following 

 measurements : 



Binnewater sandstone 32 feet 



High Falls shale 

 Shawangunk conglomerate 



The contact between the Shawangunk conglomerate and the 

 High Falls shale is concealed in this section, so that the 

 individual measurements of these beds could not be obtained. 

 In a drainage tunnel of the consolidated Rosendale Cement 

 Company, a few hundred yards away, a similar section was 

 exposed. Although this was not accessible for accurate 

 measurement, the thickness of the conglomerate was estimated 

 at ten feet, and this value was probably the approximate thick- 

 ness in the section given above. 



In this Binnewater section the Binnewater sandstone is a 

 dense white or pale gray sandstone approaching a quartzite 

 throughout. The High Falls shale is a soft, fine-grained, 

 bright red shale with very little material of any other color. 

 The Shawangunk conglomerate consists of quartz pebbles in a 

 somewhat darker colored matrix. In this exposure the details 



