98 GEOLOGY OF OHIO. 
vania and of Southern Ohio, but its distance from the Putnam Hill 
limestone below, viz., about 60 feet, militates against this view. It may 
be noted, however, that this particular interval between the Lower Kit- 
tanning coal and the Putnam Hill limestone is longer by 20 or 80 feet 
than at most other points in this region. If the interval should be 
shortened to that extent in this case, the reference of the limestone 
to the Ferriferous would be less objectionable, to say the least. 
The Cambridge limestone, in the nearest exposures to Zanesville, 
is 112 feet above the Upper Freeport coal. Its range is 112 to 132 feet 
above this horizon. The Ames or Crinoidal limestone is generally about 
100 feet above the Cambridge, but the interval is occasionally materially 
shortened, coming down to 60 feet at Blue Rock and in its vicinity. 
The Cincinnati and Muskingum Valley Railroad, running south- 
westward from Zanesville, keeps nearly on the line of strike of the 
strata, and thus along its course, the same elements that we have thus 
far followed, are constantly exposed. The complete identity of the very 
numerous and excellent sections to be found at Del Carbo, Roseville, 
McLuney and other points along the line with the Zanesville section, is 
recognized by every one who has had anything to do with the field 
in either a scientific or practical interest. The Kittanning coals, in 
particular, can be followed most directly from point to point, and no 
question as to their persistence and continuity is admissible. The 
coals and limestones are largely worked along the railroad line, and 
country banks complete the connections where mines are wanting. 
The intervals change somewhat, mostly in the way of contraction, 
throughout the region upon which we have now entered. A few typi- 
cal sections will be recorded here. 
At Del Carbo both of the Kittanning coals have long been worked 
on the large scale for railroad supply. The Putnam Hill limestone has 
also been mined here quite largely for Moxahala Furnace. The Mer- 
cer limestones both occur in their places as soon as these places are 
reached by the deepening valleys on either side. The immediate series 
at Del Carbo is as follows: 
Feet 
Middle Kittanning coal, including bone coal (No. 6)............ssseseceseeeee 43 
IN@=CLAY, -iccceetovcassentee coco cases seccus oncs'secsssccdeu conacatsstusesenmenenemecmeteatens 4 
Shales? withtirOn: Ore’ -k.....c0.sseseescovelscss cess tacos ceeoseoncnceseneemtereneeeaee 12 
Lower Kittanning coal (Oto oft.) (NOs Direc. .ccsccocleccessecciecereeceecceeers 5 
Bire-Clay; fs .cccaccecsssossceccoceseccecoctosssnvesces esse ssee cess sa ccmesestieseemenmeestns 4 
SHAlES, OtCs: csv cciccescsscccenccsecvlereoccecscsesecccnscucswsucoscsoessuceenseteemeeeetens 34 
