GEOLOGIC CORRELATION 253 
Eras 
Periods 
SUB-P. 
Series 
Terranes 
Thick 
Rocks 
1 PALEOZOIC 
Late 
Chemungan 
Interval 
Unconformity 
Snyder 
125 
Shales 
Senecan 
Callaway 
50 
Limestones 
Interval 
Unconformity 
Wittenberg .. 
30 
Shales 
Interval .. _ 
Unconformity 
Grand Tower 
150 
Limestones 
Earlt_. 
Oriskanian ... 
Clear Creek.. 
225 
Limestones 
Helderhergian. 
Interval 
Unconformity 
Bailey 
160 
Limestones 
SILURIC 
Late 
Goweran-.- _ 
Interval 
Unconformity 
Sexton 
50 
Dolomites 
Mid 
Niagaran . 
Interval . _ 
Unconformity 
Bowling Gr. 
40 
Dolomites 
Earlt__ 
A lexandrian— 
Interval 
Unconformity 
Noix 
Girardeau _. 
30 
50 
Limestones 
Limestones 
ORDOVICIC 
Late 
Maquoketan 
Bufallo 
Thebes 
60 
75 
Shales 
Sandstones 
Mid 
Mohawkmn 
Interval .. . 
Unconformity 
McCune 
50 
Limestones 
Interval 
Unconformity 
Bryant 
Joachim . _. 
150 
150 
Limestones 
Dolomites 
Early. _ 
Minnesotan 
' St. Peter 
1 
125 
Sandstones 
Canadian . ... 
1 
Interval 
j Unconformity 
Yellville 
150 
Dolomites 
CAMBRIC 
Late 
Ozarkian 
Interval 
Unconformity 
Jefferson 
Roubidoux ._ 
Gasconade 
Gunter _ 
200 
150 
250 
100 
Dolomites 
Sandstones 
Dolomites 
Sandstones 
Mid 
Croixan . 
Interval 
Unconformity 
Proctor ... . 
Eminence 
Potosi 
Doe Run 
Derby 
Davis 
LeSueur 
Frederickt’n 
LaMotte 
60 
200 
300 
60 
40 
150 
250 
200 
250 
Dolomites 
Dolomites , 
Dolomites 
Dolomites 
Dolomites 
Shales 
Dolomites 
Limestones 
Sandstones 
Early.. 
Interval 
Unconformity 
PRO- 
TER- 
OZO- 
IC 
SUPBRIORIC.—. 
Early.. 
Animikian . . . 
Ironton 
Pilot Knob... 
200 
50 
Slates 
Conglomerates 
SELKIRKIC 
Interval 
Unconformity 
