12 



OHIO FOSSILS 



FIGURE 9 - SYSTEMS EXPOSED IN OHIO COUNTIES* 



COUNTY 



ORD. 



SIL. 



DEV. 



MISS. 



PEN. 



PER. 



PLE. 



COUNTY 



ORD. 



SIL. 



DEV. 



MISS. 



PEN. 



PER. 



PLE. 



Adams 



X 



X 



X 



X 



o 







G 



Licking 



o 











X 



X 







G 



Allen 



o 



X 



o 











o 



G 



Logan 



o 



X 



X 



o 











G 



Ashland 







o 







X 



X 







G 



Lorain 







o 



X 



X 











G 



Ashtabula 











X 



X 











G 



Lucas 



o 



X 



X 











o 



G 



Athens 







o 











X 



X 



N 



Madison 







X 



X 











o 



G 



Auglaize 







X 



o 







o 



o 



G 



Mahoning 















X 



X 







G 



Belmont 



















X 



X 



N 



Marion 



o 



X 



X 



o 



o 







G 



Brown 



X 



X 















o 



G 



Medina 















X 



X 







G 



Butler 



X 



















o 



G 



Meigs 















o 



X 



X 



N 



Carroll 















o 



X 



o 



G 



Mercer 







X 















o 



G 



Champaign 







X 



X 



o 



o 







G 



Miami 







X 



X 



o 







o 



G 



Clark 



X 



X 



o 



o 



o 







G 



Monroe 



















X 



X 



N 



Clermont 



X 







o 











o 



G 



Montgomery 



X 



X 



o 



o 











G 



Clinton 



X 



X 



o 















G 



Morgan 











o 



o 



X 



X 



N 



Columbiana 



o 



o 











X 







G 



Morrow 











X 



X 











G 



Coshocton 



o 



o 



o 



X 



X 







G 



Muskingum 















X 



X 



o 



G 



Crawford 











X 



X 











G 



Noble 



o 



o 











X 



X 



N 



Cuyahoga 



o 







X 



X 



X 







G 



Ottawa 



o 



X 



X 















G 



Darke 







X 







o 











G 



Paulding 



o 



X 



X 







o 







G 



Defiance 







X 



X 



X 











G 



Perry 















X 



X 







G 



Delaware 



o 



X 



X 



X 



o 







G 



Pickaway 



o 



X 



X 



X 











G 



Erie 



o 



X 



X 



X 



o 







G 



Pike 







X 



X 



X 



X 







G 



Fairfield 







o 







X 



X 



o 



G 



Portage 















X 



X 







G 



Fayette 







X 



X 















G 



Preble 



X 



X 











o 







G 



Franklin 



o 



X 



X 



X 



o 







G 



Putnam 







X 



X 















G 



Fulton 











X 



X 











G 



Richland 















X 



X 







G 



Gallia 



















X 



o 



N 



Ross 



o 



X 



X 



X 



X 







G 



Geauga 







o 



X 



X 



X 



o 



G 



Sandusky 







X 



X 



o 



o 







G 



Greene 



X 



X 







o 



o 







G 



Scioto 











X 



X 



X 







N 



Guernsey 



o 



o 











X 



X 



N 



Seneca 



o 



X 



X 















G 



Hamilton 



X 







o 



o 











G 



Shelby 







X 



















G 



Hancock 



o 



X 



o 



o 











G 



Stark 







o 







X 



X 







G 



Hardin 







X 















o 



G 



Summit 















X 



X 







G 



Harrison 



o 











o 



X 



X 



N 



Trumbull 



o 







X 



X 



X 







G 



Henry 







X 



X 







o 



o 



G 



Tuscarawas 







o 











X 



o 



G 



Highland 



X 



X 



X 



X 



o 



o 



G 



Union 



o 



X 



X 















G 



Hocking 



o 











X 



X 







G 



Van Wert 







X 



















G 



Holmes 







o 







X 



X 







G 



Vinton 















X 



X 







N 



Huron 











X 



X 











G 



Warren 



X 



X 











o 







G 



Jackson 















X 



X 







N 



Washington 







o 











X 



X 



N 



Jefferson 















o 



X 



X 



N 



Wayne 















X 



X 







G 



Knox 







o 







X 



X 







G 



Williams 











X 



X 







o 



G 



Lake 



o 







X 



X 



X 







G 



Wood 







X 



X 















G 



Lawrence 











o 



X 



X 







N 



Wyandot 







X 



X 















G 



* O = Indicates that rocks of this age do not crop out in the county. 

 X = Indicates exposures of rocks of this age. 



G = Indicates that all or part of the county was covered by ice during Pleistocene time. 

 N = Counties not covered by ice during Pleistocene time. Quaternary deposits in these 

 areas are mainly lake and stream deposits. 



