Ordovician cephalopods are
numerous
and varied in the Pogonip
Group of westcentral Utah. The
Ordovician fossil cephalopods found in Utah are usually not very well
preserved,
alot of times all you find are endocerid endosiphocones, or partial
phragmocones contained in large ledges or boulders. The identification
of these fossils requires sectioning, so most of the fossils I find are
left in the field, and almost all of the photos were taken in the
field. The chart
below shows the lower half of the Ordovician, as I photograph
cephalopods
from these rocks I will link them to the Zone letter. So far only
zones D, G-1, G-2, I, J, L and N have links with photos.
System
|
Global Series | Global Stage | North
American Series |
North American Stage |
Ross-Hintze Zones |
| Ordovician (Part) |
Middle (Part) |
Darriwilian | Whiterockian (Part) |
Chazyan |
O |
Dapingian |
Kanoshian |
N |
|||
| M |
|||||
| Rangerian |
L |
||||
Early |
Floian |
Ibexian |
Blackhillsian |
K |
|
| J |
|||||
| I |
|||||
| H |
|||||
| Tulean | G2 |
||||
| G1 |
|||||
Stairsian |
F |
||||
Tremadocian |
E |
||||
| D |
|||||
| Skullrockian | C |
||||
| B |
|||||
| A | |||||
| Cambrian |
|||||
References:; Dattilo, B. F.,
1993,
The Lower Ordovician Fillmore Formation of Western Utah -
Storm
dominated sedimentation on a passive margin, B.Y.U. Geology
Studies Vol.39, Pt.1; Flower, R. H., 1968, Part II
-Some
Additional Whiterock Cephalopods, New Mexico Bureau Of Mines &
Mineral
Resources Memoir 19; Gil, A. V., 1988, Whiterock (Lower Middle
Ordovician) Cephalopod Fauna from the Ibex Area, Millard County,
Western Utah, New Mexico Bureau of Mines and Mineral Rescources Memoir
44;
Hintze, L. F., 1973,
Lower and Middle Ordovician Stratigraphic Sections in the Ibex area,
Millard
County, Utah, B.Y.U. Geology Studies, v. 20 pt. 4; Hintze, L. F. and
Davis, F. D., 2003, Geology
of
Millard County, Utah, Utah Geological Survey Bulletin 133; Hook, S. C., and
Flower,
R. H., 1977, Late Canadian (Zones J, K) Cephalopod Faunas From
Southwestern
United States, New Mexico Bureau Of Mines & Mineral Resources
Memoir
32.
And too few enjoyable hours talking with Dr. Lehi Hintze about the Ordovician and it's rocks and fossils.