MEDINA COUNTY. 363 
south-east. The glaciated surface is generally covered with a bowlder 
clay containing many pebbles of crystalline rock, granite, quartz, etc., 
brought from the far north, and more and larger stones derived from 
some neighboring region or locality. 
GEOLOGICAL STRUCTURE. 
A detailed account of the geological structure of the county will follow 
this introduction, the exposures of rock in each township being described 
separately. A brief summary only will be given at this point. The 
general section of the rocks exposed in the county is as follows: 
Hires O PN Te ASULE Sie at percpre terer dey Shale rece ae Sele ME SY a alg lOO 
2>  COMNCIOMEBIOS 6 Sogdssonce cocooDpaneas sobcd doa coun cade ene lace(ayeiceecrayats 135 
Sy  (CunyAlaGar SUAle CnVenreeNy PAKOIO) 665855 sega bons doce see5 abe beUdes eee. Nl) 
The Cow Measures reach into the south-eastern corner of the county, 
and Coal No. 1 is worked with profit in three mines, all in Wadsworth 
township. This bed of coal also underlies a portion of the south part of 
Sharon township, these two townships being the only ones in the county 
which contain coal. Where mined, the aa reaches a maximum thick- 
ness of nearly five feet, is of superior quality, containing but little sul- 
phur. The production of the two principal mines cee 1871 was over 
fifty thousand tons. 
The Carboniferous Conglomerate is exposed in seven townships, all in 
the two eastern tiers excepting Guilford. But most of this conglomerate 
region shows the Cuyahoga shale of the Waverly group in the deeper 
ravines ; in fact, the prevailing rock in Medina county is of this older 
division. Some fair building stone is quarried from the Conglomerate, 
but a great portion of this rock is unfit for building purposes. The 
character of the Conglomerate varies materially in the several places 
where exposed. In general the pebbles contained in it are quite small, 
and compose no considerable part of the formation, sand constituting 
the bulk of the material. The estimated thickness of the Conglomerate 
in Medina county is one hundred and thirty feet. 
The Waverly series, or the upper division of it, now named Cuyahoga 
shale, is the third and oldest group of rocks found in Medina county, 
the greater portion of the Drift being immediately underlain by the 
Cuyahoga shale, which is exposed in a majority of the townships. 
Roughly estimated, the Cuyahoga shale in Medina county may be said 
to have a thickness of two hundred and fifty to three hundred feet. 
This formation is exceedingly rich in fossils, some of the characteristic 
species being Hemipronites crenistria, Productella Newberry, Sanguinolites 
