FEATURES OF TRAP EXTRUSIONS IN NEW JERSEY 317 



calcite, but the irregular cavities from which they have been dissolved 

 have frequently been noted. 



The surface areas on which I found these structures in the imme- 

 diate vicinity are indicated on the map. 



Let us now go southward about three miles to an old trap quarry 

 near the Great Notch, formerly worked by Francisco Brothers. 



••<>? 



r/g./2. 



Fig. II 



Unfortunately no work has been going on here for several years so 

 that the features to which I wish to call especial attention can now 

 be seen at a few points only, though formerly visible over a good 

 part of the quarry. Fig. 10 is 

 from a sketch of the south side of 

 the quarry made in 1902, and 

 Fig. 1 1 is of the east side made at 

 the same time. The bowlder- 

 forms noted in the West Paterson 

 quarry were well developed and 

 the crystal vugs were also present ; 

 but a new feature to be noted is 

 what at first sight appears to 

 be a breccia of sharply defined, angular blocks of sandstone, ranging 

 up to a foot in diameter, lying in the midst of the trap. Their 

 presence in a surface flow of lava might be extremely puzzHng until 

 some such occurrence as that shown in Fig. 12 is noted. From a 



