Mar., 1922 cavities filled with glacial material 127 



slack-water silt deposits such as are in many cases associated 

 with glacial deposits. The composition and shape of the 

 pebbles and cobbles and the amount of wear show that the 

 gravel is glacial material. How did it come to its present 

 position fifteen feet below the surface and apparently enclosed 

 in the dolomite? The stone above is compact, bedded dolomite 

 without any known natural opening through it. Numerous 

 drill holes have been sunk for blasting the stone and some of 

 these show on the quarry face, but the silt clay is very different 

 from the calcareous slime derived by wash from the drillings 

 and the packing used in the drill holes is distinct from the 

 sand and gravel filling. 



The characteristics of abundant calcite, cavities more or less 

 filled with calcite, and the enclosed silt and gravel deposits, 

 are present along the quarry face for more than a hundred 

 yards; that is, these are characteristics of a zone. The strata 

 here dip west into the quarry wall at an angle of about five 

 degrees and if this zone is projected upward it would meet 

 the level of the general rock surface about forty-five yards east 

 of the present quarry wall. In fact, such a position of outcrop 

 is shown at the south wall of the quarry. The cavernous 

 character of this zone continued to the outcrop and it was 

 by these openings that the glacial material entered. The first 

 material carried down and deposited was sand and gravel with 

 cobbles. The coarser material was deposited only in or near 

 the more open channels like the one described above. Some 

 of the sand was carried into the smaller crystal-lined cavities 

 and deposited around the crystals. 



The deposition of the clay followed that of the sand and 

 gravel. Much of it is laminated and the material is very fine 

 grained, indicating deposition from relatively quiet water which 

 apparently filled all the cavities of the zone. The deposition 

 continued until the cavities were completely filled, even to the 

 placing of laminated clay in small irregularities in the roofs 

 of the cavities. At other places the cavity filling was only 

 partial or absent entirely. 



The ground water level of the region at the present time is 

 about 15 feet beneath the surface and it is evident that these 

 cavities go deeper than this, and in another quarry this same 

 zone contains much calcite filling, although few open spaces, 

 at a depth of 45 feet. It is not known to what depth the 



