PORTAGE COUNTY. 137 
GEOLOGICAL STRUCTURE. 
The number and relative positions of the strata which come to the 
surface within the limits of Portage county will be seen at a glance by 
reference to the section given below: . 
FT. 
ils fSinjoeraikeren tele ny hal oar hyGlloguoas soso eo seee en Usb oolas ooSoEe 10 to 100 
EST ALOPAN URS ANOSUOM Chemie el yok eed ee. Badenian teaver apc as 50 
SHOT CS TOM CRioma ears se sie oe Mae EMSA GOL U0 a SERENA ogi oe Lye) Ae nars 2u Oto 4 
AMO OIM NORA Seer eer ne Re eM hey ALLA ONLI Leis Dac J Het Nat Nee Pea IO 5) 
Dy) ITEC V ONG hie eee Re eh as AE RSS Pa et RNs eA Ua a A 3to 4 
GyaShaleyandssandstomeys. mays anya wane GAC Ei aaa Nay Ae ae 25 to 30 
Ten UIDBOTANES OV OV EY Ota REN AIE y ASee LENAE SGP A AI om DAIS SR ea Oto 4 
SER OWING ceyeee teste Mets We gael noe aN Mane RULE Cae Mioeee ce UR SS acai Lela to 3 
ited ISTE EE Ge es em Beara etale tay eos a iste 3to 12 
FiOS ASSO Sa ea A I A Dal OA a a 20 to 50 
MASA FE Rages CO, Ch EIGEN p72 Re eA ag Nae I OC SN a le FE A NREL EE GER SR LO 7 OFCOM 
ED eee UTI CLS HOTA Opies nee pate wane ie Me Rael LOR OP ge SIO ed A NOE sh eh ts or 50 to 100 
ays PSH KEY CO BSS een eee eRe ait ces iia ri Nall Eure eet Aten eae ey ay Oto 50 
AR Ca bNo iy yasuteayunne Numer Aaa Ata om nO ey ale Pn AA La EERE 2 “Om & 
MEIC CLV apetets caer ye geuara SpoveteMined sce Sis AaCcys Le A Navy oc Sen MM Wu ta he 3to 5 
1@, Shale emel samdlyrome ssss uso seessa sooase Pape A nym cindy. CMU CMAN ZY fee 25 to 50 
RO ON CLONE HALO carey Lesa mds Ret snON a enon eter Satu nem ame yee Line 100 
All the rocks enumerated in the preceding section belong to the Car- 
boniferous system, of which they represent two members, viz., the Con- 
glomerate and the Coal Measures. The area of the county is about 
equally divided between the two formations. All the northern half has 
the Conglomerate for its surface rock, though it is generally deeply 
buried by Drift clays. It is fully exposed in the valleys of the Mahoning 
and Cuyahoga. The trough of the latter stream is cut in the Conglom- 
erate all the way from the point where it enters the county, in Hiram, 
to its place of exit, on the west side of Franklin. The Conglomerate is 
well seen in Mantua and Garrettsville, and still better in Franklin and 
Nelson. In all these localities it exhibits essentially the same charac- 
ters, viz., a coarse, drab-colored sandstone, in places thickly set with 
quartz pebbles from the size of a pea to that of an egg. In some places, 
as in Windham, the stone it furnishes is finer, whiter, and more homo- 
geneous, and would answer admirably for architectural purposes. As a 
general rule, however, it 1s rather coarse for all fine work, but furnishes 
a strong and durable stone, well adapted to bridge-building, cellar walls, 
and, indeed, to all plain and massive masonry. 
Near Kent certain layers of the Conglomerate have been found, which 
are white enough to serve for the manufacture of glass. The coloring 
matter of the rock is usually iron, and it here contains much less than 
usual. 
