100 GEOLOGICAL RECONNOISSANCE 
tage of the cavernous opening made by nature, beneath the cliff of con- 
clomerate: 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,Warton’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 
