14 ANNUAL REPORT 
: Feet 
Lower Helderberg limestones... - sso nea oeines 160 
Niagara limestone ies Has ces. ieee Saeed SNe Re 200 
Niagara shale, and Clinton limestone................ 105 
Medina): shiple:s aici cies ene ioe opto ae eS es 105 
Cincinnati (Hudson River) shale.................... 450 
Uitleal Shale see ee oxic cet iain ena a arn en ORT NET 308 
Trenton limestonesaty 32. soe coe es etree ae ere eons 1,328 
Next is given a record of a well near Rollersville, in the southern 
part of Madison township; the well head is 689 feet above tide level: 
Feet 
Drive Pipe sears Vea Sas ae shea oe ek TRS ae 30 
( Gray JdMESTOME eee eet ea ees 140 
Whitenlimestones sashes ene 160 
f : Blue limestonen jr) eccrine iierorene 20 
Niagara Series White slate: (first break)/>.-2.-...... 2 
Brownelimestonem (iad) prec ale 
| Light slate (second break)........... 20 
Clinton limestone tec eros oe oe ee eee eres 100 
Medinazshales:sred:\isofts 2k Ain chs caine eee To eee 80 
Cincinnabtin GCENUIGSOHBEMVeT) mS lial eC Serene rennin ienretere 427 
Utica shales (brows) Soa: occu ctereromiete renee ere 25216 
Prenton JIMEStOME Mab.) sh /sssecte ccc helouere Gude Seats OR ine een 1,2521%4 
From this it is seen that the Trenton rock lies about 563 feet below 
tide level; it dips very gently to the north, being found 586 feet below 
at Woodville seven miles distant; near Lindsay, in the northern part of 
Washington township, it is 650 feet, and at Fremont 720 feet. In other 
words, the Trenton rock lies highest in the southwestern corner of the 
township, sloping very gently to the north, and in the same manner to 
the east. In the latter direction, however, the rate soon changes, and as 
a result the depth of the Trenton is found to increase rapidly, as is shown 
by the Fremont well. 
The Oil-rock.—This is in all cases the Trenton limestone. Its charac- 
ter agrees in every respect with that found in Wood and other counties. 
Formerly it was customary to drill a few feet only into the oil-rock; later, 
depths from 50 to 100 feet were reached, and this custom now prevails, 
especially with the largest producer in the field—The Ohio Oil Company. 
The greater depth has the advantage of penetrating a possible deeper pay, 
and also acting as a cistern into which the sediments may accumulate. 
All wells are torpedoed, the size of the charge ranging ordinarily from 
50 to 200 quarts. The pay commonly ranges in thickness from 5 to 30 
feet ; it is more porous and commonly has a darker color than the enclosing 
rocks, and hence is easily recognized. 
Barren Area.—As has already been stated there is one conspicuous 
barren area; this has a length of ten miles and a width usually of from 
