472 T. C. Brown — ShaioangunJc Conglomerate. 



have been removed. The upper bed consisted of coarse quartz 

 pebbles embedded in a finer grained matrix. Ten feet from 

 the upper surface came a layer of olive-green shale one foot 

 thick and beneath this the rock was mostly fine-grained, pure 

 white sandstone with occasional conglomerate beds. There 

 were several layers of the green shale a few inches in thickness 

 and occasional partings of black shaly material a fraction of an 

 inch thick. The contact of the conglomerate and the Hudson 

 River shale was also well shown in this shaft. The uncon- 

 formity was sharply defined ; the Hudson River beds were 

 dipping at a considerable angle and the lower part of the 

 Shawangunk beds consisted of two to three feet of light olive- 

 green shale. Above this the conglomerate was hard and coarse- 

 grained. 



Shaft 5 passed through 50 feet of drift, partly till and partly 

 laminated clay, and then penetrated the Shawangunk con- 

 glomerate, 255 feet thick, under conditions similar to those 

 described for shaft 6. 



Shaft 4 passed from the overlying limestone through both 

 the Binnewater sandstone and High Falls shale into the Sha- 

 wangunk conglomerate. The thickness of these beds has been 

 given above under Hole 32, which occupied the same position. 

 This shaft exposed the best unweathered section of the Binne- 

 water sandstone ; it consisted at the top of a dense quartz 

 sandstone layer and below of alternating sandy and shaly bands 

 a few inches thick ; it was gray to greenish in color and con- 

 tained considerable calcareous material. Quite a proportion of 

 this calcareous material had been dissolved out, leaving the 

 rock porous and honeycombed, with numerous cavities often 

 lined with minute calcite crystals. The High Falls shale in 

 this shaft was green to black in color, rather porous in places 

 and it contained a considerable amount of iron pyrite. Iron 

 pyrite also occurred in the upper few feet of the Shawangunk 

 conglomerate. 



Summary of Observations. — The observations on these three 

 formations in the vicinity of High Falls may be summarized 

 as follows : 



Binnewater sandstone. — In the type locality near Binnewater 

 this sandstone is dense, white, and quartzitic, 32 feet thick. 

 In the gorge of the Rondout at High Falls only a few feet at 

 the top have the characteristics of the formation at the type 

 locality. The remainder of the formation consists of thin- 

 bedded alternating shaly and sandy layers, often showing 

 ripple marks and sun cracks, and gray to green in color. In 

 shaft 4, the locality farthest from the outcrop of any section 

 studied, the upper thin layer of white quartzitic sandstone was 

 recognized. Below this the formation consisted of alternating 

 thin beds of sand and shale, often calcareous and with 



