REPORT OF THE DIRECTOR AND STATE GEOLOGIST 1902 r93 



dropped their burden at the edge of the glacial lake. Many of 

 these peaks may have been formed by the shifting of but a single 

 stream. The range is marked by kettlelike depressions which are 

 commonly known as kettle holes, usually supposed to have been 

 formed by the melting away of large bodies of ice buried in the 

 earthy mass. The material in the range, though irregularly dis- 

 tributed, exhibits a tendency, in most cases, to become finer on 

 the lakeward side, in the general direction of dip. The section 

 made by the Cobb's hill pit is upward of 100 feet at the back and 

 affords a good opportunity to study the character of the range on 

 the iceward or northern side. A succession of step-faults shown 

 here may be mentioned as a usual feature in pits in the north 

 side of the range. These faults are due, it has been supposed, to 

 the settling of the mass on the removal of the ice support from 

 that side. 



J. Y. McClintock, commissioner of public works, says the 

 amount of sand and gravel removed from the Cobb's hill pit is 

 about 360,000 cubic yards all told. As this has been taken away 

 since 1891, it will serve as a means of determining roughly what 

 the output has been each year. 



Mr Barnard states that a little over 4000 yards from this pit 

 were used on the Erie canal towpath last year. . 



The sandpit next in quality of material is that of J. S. Shee- 

 han, located % of a mile south of the Erie canal in the village 

 of Brighton, at the end of the range and about a mile from the 

 above pit. Mr. Sheehan has also a large gravel-pit just west of 

 his sandpit. The output from these pits for the year was 7000 

 cubic yards. 



Michael D. Sheehan has a small sandpit adjoining the above 

 mentioned sandpit on the north. 



This year Mr J. Schrader has developed a pit on Highland 

 avenue % mile southwest of Monroe avenue on the southeastern 

 side of the Pinnacle range. At the present stage of excavation, 

 there is a good road gravel in the upper portion and a fine brick 

 sand in the lower. The output for the last year was about 800 

 cubic yards, most of the material being used for roads in Brigh- 

 ton and Henrietta townships. This coming year, Mr Schrader 



