Sandusky Bay and Cedar Point 207 



turn the auger through six or eight inches of sand. From here 

 on the sand increases rapidly. A quarter of a mile south of the 

 Rear Range Light we bored through six feet of it without reach- 

 ing the bottom. The layer of sand found between a mile and a 

 mile and a quarter north of the city is not at the surface of the 

 mud but a few inches below it, while several feet of mud inter- 

 vene between the sand and the clay. As long as the entrance to- 

 the bay remained narrow it is probable that great waves travers- 

 ing the lake were checked enough there to prevent sand being 

 carried so far toward Sandusky, but when the washing away of 

 Spit Island widened the opening much of the obstruction was 

 removed and the great storms of about 1860 distributed sand 

 (some of it, no doubt, derived from Spit Island) farther in the 

 bay than it had come before. In later years the narrowing of 

 the entrance by the construction of a submerged jetty extending 

 northwest from the Outer Range Front Light as well as the 

 scarcity of great northeasters may have prevented further- 

 accessions of sand and given time for mud to be deposited on 

 top of that which was left here in former years. 



We have never found thick deposits of sand except where 

 it had apparently come in from the lake. The bar west of 

 Biemiller's cove has much sand and gravel which has been 

 moved along shore from the north, but a short distance west of 

 the bar the sand forms only a thin surface layer. 



WORK OF THE GLACIER AND PREGLACIAL 

 CHANGES. 



The glacier rested heavily on the region about Sandusky 

 and left its impress on the rock in many places, the grooves of 

 Kehey's Island and Marblehead being larger than are known 

 elsewhere. Near the ncrth shore of the bay large grooves 

 have been noticed north-east of Hartshorn's dock and at the 

 Ohlemacher quarries. Al:ng the south-east shore of Johnson's 

 Island are numerous distinct grooves extending beneath the 

 water. On the higher ground back from shore they are con- 

 tinually being uncovered in stripping the rock as the quarry is 

 extended and a number of fine ones have been quarried away in 

 the last three years. In the city of Sandusky wherever the 

 overlying clay "^is sufficiently deep to protect the rock from 

 weathering, its removal discloses glacial marks. Near the bay 

 we have noticed them at the Ship Yard and in the basement of 

 Emerich's drug store. In the summer of 1904 when the founda- 

 tion was being prepared for the concrete work at the foot of 

 Columbus Avenue, a piece of limestone showing plain glacial 

 marks was broken off twelve feet below the surface of the water. 



