100 GEOLOGICAL RECONNOISSANCE 



ta°e of the cavernous opening made by nature, beneath the cliff of con- 

 glomerate: already the bed is so difficult of access, back in the recesses of 

 the cliff, that even with all the height, obtainable by the removal of the 

 whole thickness of the shale, a space of only from 18 to 24 inches is 

 cleared between the hard sills of sandstone, to work in, and it has become 

 therefore necessary, in order to obtain any coal, that the workman should 

 lie on his side and work his pick in this uncomfortable position. 



By computation, the coal under this conglomerate is at least 400 feet 

 above the valley of King's river. It is underlaid by millstone grit, suc- 

 ceeded, in the descending order, by a great thickness of marly shales, 

 under which are the Archimedes, and encrinital limestone and associate 

 sandstone. No continuous section was obtained where the relative thick- 

 ness of the different members could be measured. 



In summits of the highest ridges, near the head of King's river, about 

 200 feet of red and variegated shales and sandstone come in over the 

 conglomerate. In this space, coals of workable thickness are more likely 

 to occur than under the conglomerate; and the inhabitants of Madison 

 county would do well to make diligent search for outcrops of coal, in these 

 higher measures. As yet, however, no symptoms of coal have been dis- 

 covered amongst these superior shales, in the south-eastern part of Madi- 

 son county. 



Some pieces of lead ore are reported to have been picked up in the 

 valley of King's river, viz: in the Basham and Roebuck settlement on 

 Dry creek, three miles above Kingston; also by Burney, higher up the 

 valley, near the head of King's river. At the latter locality, the rocks 

 being mostly conglomerate sandstones and shales, which have not retained 

 that openness of fissure requisite for the retention of metallic insinuations, 

 it is not likely that productive lodes should occur, accessible to any rea- 

 sonable amount of shafting; at the former, where the underlying lime- 

 stone formations are nearer the surface, the prospect is somewhat more 

 favorable; but still I do not consider the geological indications, in the 

 south-east part of Madison county, as encouraging for mining operations 

 as in the northern part of this county, where the barren and cavernous 

 cherty limestones immediately underlie the country; the reason for this 

 conclusion will appear more fully when treating of Benton county. 



From the forks of King's river, we ascended for several miles on the 

 western branches of that stream, and then rose 460 feet to the divide 

 between King's river and "YVarton's creek. In this ridge, the Archimedes, 

 pentremital, encrinital, and other members of the upper division of the 

 subcarboniferous limestone group were found in force, with intercalations 

 and partings of shale and marl, with some alternations of ferruginous 



