depth so many hundred times as would be necessary to produce all the 

 variations to be read in a thickness of five hundred feet. Pure limestones 

 are made in the deeper waters and fine argillaceous sediments may settle 

 in the deeper or the shallower places. 



But there appears to be ample reasons for believing that the sea in which 

 the Hudson River rocks of Indiana and Ohio were deposited had its shore 

 line far away, or in other words, said localities were near the middle of a 

 continental ocean. 



How then can we account for such well defined successions of mechan- 

 ical deposits for so long a period of time? How could these sediments 

 get so far from shore and how could they recur so sharply bounded as 

 they are from the purer limestone and other consolidated ledges? How 

 came it about that there were such numerous alternations of life and death 

 epochs- in the same fifty, or five hundred feet? The answer to these ques- 

 tions may be very easy to some geologists. We have not, however, seen 

 them satisfactorily answered. Their solution, whatever it is, will be the 

 opening of a door to other secrets. 



The traps of Redhead, N. B. By V. F. Marsters. 



Exhibition and explanation o\- a geological chart. By Eiavood P. Cub 



BERLY. 



Glacial and preglacial erosion in vicinity ok Richmond, Ind. By Joseph 

 Moore. 

 Richmond is on Drift, underlaid by upper layers of Lower Silurian 

 known as rocks of the Hudson River Group. These rocks being of the 

 earlier time have been above the sea for ages. Consequently there was 

 plenty of time for them to be much eroded. I shall not in this brief pa- 

 per specify all the well-marked features of erosion but will allude to a 

 few special examples. There is a buried river channel a few rods west oi 

 the present channel of Whitewater. This was reported nearly fifty years 

 ago by Dr. Plummer, of Richmond, but it was not then so well known in 

 its extent and direction as it has since become by means of wells, tile 

 layers and ditches for water and gas mains. Said buried channel is about 

 seventy feet wide where crossed by the national road and its walls are verv 



