| Cason Shale | |
| Type: | Formation |
| Age: | Ordovician-Silurian |
| Prilithology: | Shale |
| Namedfor: | Cason tract and mine, near Batesville, Independence County, Arkansas |
| Namedby: | Henry Shaler Williams[1] |
| Region: | Arkansas |
| Country: | United States |
| Unitof: | none |
| Underlies: | Brassfield Limestone |
| Overlies: | Fernvale Limestone |
| Thickness: | up to appx. 23 feet[2] |
The Cason Shale is a Late Ordovician to Middle Silurian geologic formation in the Ozark Plateaus of Arkansas.[2] The name was introduced in 1894 by Henry Shaler Williams in his study of Arkansas.[1] Williams designated a type locality at what was known as the Cason tract and mine, near Batesville, Independence County, Arkansas, however, he did not assign a stratotype. As of 2017, a reference section has not been designated for this unit.
A. inornatus
A. unicostatus[3]
A. triangularis[3]
B. flexa[3]
B. inclinata[3]
B. ornata[3]
C. delicatus[3]
C. flexuosus[3]
D. mehli[3]
D. posterocostatus[3]
D. procerus[3]
D. kentuckyensis[3]
D. homocurvatus[3]
D. simplex[3]
E. delicata[3]
H. staurognathoides[3]
H. equidentata[3]
K. gracilis[3]
L. egregia[3]
L. silurica[3]
N. bicurvatoides[3]
N. planus[3]
O. venustus[3]
O. gaertneri[3]
O. tenuis[3]
P. multicostatus[3]
P. trigonius[3]
P. gracilis[3]
P. miseri[3]
P. simplex[3]
P. sulcatus[3]
P. unicostatus[3]
P. undatus[3]
P. extensus[3]
P. irregularis[3]
S. insculptus[3]
S. manganiferus[3]
S. procerus[3]
S. sweeti[3]
S. wolfordi[3]
T. superbus[3]
T. brassfieldensis[3]
T. carinata[3]
T. diminuta[3]
T. exacta[3]
T. variflexa[3]
Z. mira[3]