628 GEOLOGY OF OHIO. 
It must, however, be observed, that this ledge, in the central and north- 
ern portions of the county, is not in immediate contact with the Wa- 
verly black slate, but is separated from it by a varying number of feet of 
soft shales and clays. The distance between the upper surface of the 
slates and the quarry beds is sometimes as great as twenty-five feet, but 
is generally less than twenty feet. This heavy ledge fails altogether in 
the exposed sections of Pebble and Benton townships, its place in the 
scale being there occupied by shales, seams of fire-clay, layers of concre- | 
tions incrusted with a thin scale of iron, together with many thin and 
worthless beds of impure sandstone. The above enumeration will also 
apply with sufficient exactness to the one hundred feet overlying the 
Buena Vista ledges in the region east of the Scioto. The general com- 
position of these clays and blossoms of ore is shown in the appended an- 
alyses. Number 1 is a clay from Grege’s farm, between the black’ slate 
and the brown stone; number 2 is a fair representative of the clays 
that compose a notable part of the series for one hundred feet at least 
above the black slate in Pebble township; and number 3 gives the con- 
stitution of the scale of ore that incrusts the concretions to which refer- 
ence has already been made: 
BiTCIE ACTA ieee retell) uameneantes awoniocara tenance nMmaieueee ecient aman 61.00 61.16 
ATIMTD ANY sc, sce auieetees cen comaeneesectoes etucctiecront famneneaRae etn Bes 22.25 22.79 
SESCUMIOKIGESTOMN NOM ws aceecactliocioatenneccessaetnentas ssecoeeeeons 5.55 4,.8h 
Poi, Pee TIN DNS ciara te SoU re aaa eee eens 0.70 0.76 
WTR ene EY Haicecbe Secoceec bbcan candse Gobodp.cds000 os0000 200000 boddEG HoBJoGON. OF 1.40 1.40 
Potashrand ssod acidic son es cee ncoten ceetacs the daucctee io gcacannatceerguennenae 3.90 2.75 
NAY were): (O}a 1] OTB OVEY6 W indtyaay donocel ooddod Gbqade sr 7dh dobnes o00000 bbodme andonaNGS ode 4.80 5.80 
No. 3 
STCIOUSMA LET cosesweeseccsseeeraesleseass nonesouacces tosses st ipscieeeceaiesneelanamniie seat a 32.12 
Sesquioxide Of GrOM.........ce.c.ce, ccceceese coeneveee seeveese veneer aeecosars costes oseoen eee 93.97 
PY cp hoauh ats eee ee pe APR PERCU AR SAR CR nero eer OE CABO U OO CR nH CON OLDS Oe CU RCO eC ANA SelododAA au ohedes 1.80 
Mangamese.....cc.seceee res eeceee eeneeener seeeene: Av ER SBGa50 108.0000 HuDEDD aaHOGHE9 daedda SoogGoEKE 1.00 
Phosphate Of Vine ......:.cccsseceee soveveene soceee cvevee enceee an eece severe seweersecrer orcece 2.11 
Nees nVersitay BNAKOR GIN OTe p3coc6 poasen Goo906 ¥a093 ceeeobues Ronace sodndcdaeAcE Hedoadcdy otcaaceK trace 
Water, COMbIME ...........ccccccccnrcccnsnccenasansses su creeen sseses sorter cavsesoes cone race 8.30 
99.30 
MWS UROL T 0] er CORRE HR REA a SASH aI RHAG Ah GS Gale Te aGias Bema odie beaced acbacnicie, nougadoae Behar! 
Phosphoric Acid ......001 ceeeeeees ceeseceee ceenes ee SEE UE ery Pua Hela HAGA nUT ARIA RAO 1.279 
‘The large amount of potash and soda in analyses 1 and 2, and the equally 
‘unusual percentage of phosphate of lime in No. 3, are points of sufficient in- 
terest.to be noticed here. These are the substances upon which, more than 
