1913.] NATURAL SCIENCES OF PHILADELPHIA. 119 



It has several times been mentioned above that the uppermost 

 beds of the Triassic are, in general, conglomerates. But as this term 

 may cover rocks of quite a variety of characters and origins, it seems 

 worth while to describe them more definitelj'. For this purpose 

 those developed along the northern boundary for twentj^ miles 

 westward from the Delaware River have been selected, since they 

 are believed to be typical of the formation, and since, by reason 

 of their accessibility, it has been found possible to study them in the 

 greatest detail. 



The most striking feature of the Triassic area in northern Bucks 

 and southern Northampton and Lehigh Counties is the occurrence 

 of rather prominent hills, the highest attaining 980 feet above tide, 

 or 500 feet above the usual level of the red-shale region, and ex- 

 ceeding those formed by both the diabase and gneiss, usually 

 regarded as the. most resistant of rocks, in the immediate vicinity. 

 On these hills, in spite of deep dissection and frequent steep slopes, 

 very few exposures of rock in place are found, although the soil is 

 strewn with boulders and pebbles of pink-stained quartzite. This 

 material has been previously interpreted in three ways, as Cambrian 

 (Chickies or Hardyston), Ordovician (Shawangunk or Green Pond), 

 and metamorphosed Triassic. The present view of the matter is 

 that, while the quartzite of the pebbles is actually of the second of 

 these ages, the pebl^les themselves are not of recent origin, but 

 have weathered out of a conglomerate belonging to the ordinary, 

 unmetamorphosed Triassic series. 



This conclusion has been reached as follows: At a few places 

 along the hill slopes and at two localities where prospecting for 

 copper has been carried on, the rock can be seen in pl'ace. It consists 

 of a soft red mud ground mass in which are imbedded pebbles of all 

 sizes up to two feet in diameter, but mostly around three inches, 

 rudely but evidently assorted and stratified. The largest and most 

 thoroughly rounded of these consist of a gray to pink quartzite, 

 often in itself conglomeratic — containing white quartz grains up to 

 half an inch across, and occasional flakes of graj^ slate. These 

 quartzite pebbles are usually stained deep red by a film of hematite, 

 which penetrates the cracks and spreads out around them in rounded, 

 imperfectly dendritic patches. At the copper prospects above 

 mentioned thej-also show abundant malachite stains, which in at 

 least one specimen seemed to be derived by weathering of a copper 

 sulfide originally imbedded in the quartzite itself, but now leached 

 out, leaving tiny holes. 



