928 GEOLOGY OP OHIO. 



in thickness, occurs. It is named in the section the Iron Point ore. 

 This identification is not beyond question, but the interval, and the 

 character of the ore, and its outcrop, seem to make it probable. 



An interval of sixty-five feet filled with sandstone and with reddish shales 

 next succeeds, without any recognized elements of economical value, 

 above which the Cambridge Limestone finds place, completing the section. 

 The limestone is one hundred and seventy feet above Coal No. VI, which 

 is a smaller interval by ten or fifteen feet than is generally found. 



The section is thus seen to be very full and satisfactory. It answers, 

 without change, for all of the leading elements of the scale throughout 

 the western part of York township and the eastern part of Starr, and 

 through Brown and Madison townships, or, in other words, to the line of 

 the Marietta and Cincinnati Railroad. It is repeated with almost iden- 

 tical measurements in Rich Hollow Hill, three miles south east of Zaleski 

 (Section 30, Madison township), where the westernmost exposure of the 

 Cambridge Limestone in that vicinity is found. 



Two sections, taken respectively at Ironton and on the river hills of 

 the Monitor Furnace lands, opposite Ashland, Kentucky, will next be 

 presented. These sections faithfully represent the lower Coal M-asures 

 of this part of the Ohio Valley. An average of many sections would 

 scarcely charge the measurements found by the engineer's level in the 

 hill8 which were selected for this purpose. 



The section in the right hand column was taken immediately back of 

 Ironton. The block ore, which is made the base, lies sixty feet or more 

 above low water. It is the highest of the three seams of block ore that 

 constitute so important an element in the supply of the weetern furnaces 

 of the district. It is well shown at Kronnacher's spring house, just above 

 the Iron Railroad. It is here two feet in thickness, and is rich in iron, but 

 it is also highly charged with sulphur, and it has, therefore, after repeated 

 trials, been rejected as worthless for the blast furnace. Its character has 

 been discussed on preceding pages, and nothing need be added h.-re. 



The heavy ledge of sandstone that covers it has been worked in the 

 neighborhood for furnace hearth-stones. On the Kentucky side of the 

 river, e.-pecially, stone from this horizon has a very good name in con- 

 nection with this use. The Belfont hearth-stone quarries belong here. 



A coal Si am, locally known as the Conway coal, is found forty feet 

 above the Block ore. It has here a thickness of two feet, and has been 

 worked, in the small way, for neighborhood supply. It is through this 

 coal, and the rocks associated with it, that the tunnel of the Hecla 

 Furnace turnpike has been carried. A prostrate tree is fineh' shown in 



