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Geological feature in Michigan USA
The Four Mile Dam Formation, also called the Four Mile Dam Limestone, is a
geologic formation in
Michigan. It preserves
fossils dating back to the middle
Devonian
period.
Stratigraphy of the Devonian deposits of the northern part of the Lower Peninsula of Michigan, showing the Four Mile Dam Formation
[1]
Fossil content
Vertebrates
Acanthodians
Conodonts
Conodonts reported from the Four Mile Dam Formation
|
Genus |
Species |
Presence
|
Material |
Notes |
Images
|
Acodina
|
A. formosa
|
[3]
|
|
Also found in the
Detroit River,
Traverse,
Dundee,
Bell,
Alpena and
Norway Point formations.
|
|
Belodella
|
B. devonicus
|
[3]
|
|
Also found in the
Detroit River,
Traverse,
Antrim,
Alpena and
Norway Point formations.
|
|
Icriodus
|
I. latericrescens latericrescens
|
[3]
|
|
Also found in the
Traverse,
Bell,
Ferron Point,
Genshaw,
Newton Creek,
Alpena,
Norway Point,
Potter Farm and
Thunder Bay formations.
|
|
Ozarkodina
|
O. willsi
|
[3]
|
|
Also found in the
Detroit River,
Traverse,
Antrim,
Dundee,
Alpena and
Norway Point formations.
|
|
Polygnathus
|
P. varcus
|
[3]
|
|
Also found in the
Traverse,
Antrim,
Alpena,
Norway Point and
Thunder Bay formations.
|
|
Placoderms
Invertebrates
|
|
|
Color key
|
|
Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
|
Brachiopods
Brachiopods reported from the Four Mile Dam Formation
|
Genus |
Species |
Presence
|
Material |
Notes |
Images
|
Douvillina
|
D. distans
|
Four Mile Dam,
Thunder Bay River,
Alpena County, Michigan.
[4]
|
|
Also found in the
Hungry Hollow Formation and
Logansport Formation.
|
|
Leptalosia
|
L. radicans
|
Four Mile Dam,
Thunder Bay River,
Alpena County, Michigan.
[4]
|
|
Also found in the
Norway Point,
Gravel Point,
Alpena and
Genshaw formations.
|
|
Longispina
|
L. emmetensis
|
Dock Street clay member.
[4]
|
|
Also found in the
Alpena Limestone and
Gravel Point Formation.
|
|
Megastrophia
|
M. gibbosa
|
Four Mile Dam,
Thunder Bay River,
Alpena County, Michigan.
[4]
|
|
Also found in the
Hungry Hollow Formation and
Logansport Formation.
|
|
Oligorhachis
|
O. oligorhachis
|
Four Mile Dam,
Thunder Bay River,
Alpena County, Michigan.
[4]
|
|
Also found in the
Gravel Point Formation.
|
|
Pentamerella
|
P. alpenensis
|
Dock Street clay member.
[4]
|
|
Also found in the
Alpena Limestone and
Gravel Point Formation.
|
|
P. sp. C
|
Dock Street clay.
[4]
|
A complete specimen.
[4]
|
|
|
Protoleptostrophia
|
P. lirella
|
Dock Street clay member.
[4]
|
|
Also found in the
Norway Point Formation and
Alpena Limestone.
|
|
Schuchertella
|
S. anomala
|
Possibly the Dock Street clay member.
[4]
|
|
Also found in the
Gravel Point Formation.
|
|
S. sp.
|
Four Mile Dam,
Thunder Bay River,
Alpena County, Michigan.
[4]
|
|
|
|
Spinulicosta
|
S. mutocosta
|
Four Mile Dam,
Thunder Bay River,
Alpena County, Michigan.
[4]
|
|
Also found in the
Bell,
Rockport Quarry,
Ferron Point,
Beebe School,
Thunder Bay and
Potter Farm formations.
|
|
Strophodonta
|
S. erratica
|
Dock Street clay member.
[4]
|
|
Also found in the
Alpena Limestone and
Gravel Point Formation.
|
|
S. fissicosta
|
Dock Street clay member.
[4]
|
|
Also found in the upper
Gravel Point Formation.
|
|
S. nanus
|
Dock Street clay member.
[4]
|
|
Also found in the
Alpena Limestone and
Gravel Point Formation.
|
|
S. paula
|
Dock Street clay member.
[4]
|
|
Also found in the
Alpena Limestone.
|
|
S. sp. B
|
Dock Street clay member and overlying crystalline limestone beds.
[4]
|
Several specimens.
[4]
|
|
|
Rhipidomella
|
R. penelope traversensis
|
Thunder Bay River,
Alpena County, Michigan.
[4]
|
|
|
|
Corals
Corals reported from the Four Mile Dam Formation
|
Genus |
Species |
Presence
|
Material |
Notes |
Images
|
Aulocystis
|
A. cooperi
|
[5]
|
|
Also found in the
Plum Brook shale, Silica shale and
Potter Farm Formation.
|
|
A. jacksoni
|
Dock Street clay member.
[5]
|
|
Also found in the
Silica Shale,
Ferron Point Formation,
Petoskey Formation,
Hungry Hollow Formation, Widder Shale, Wanakah shale and
Centerfield Limestone.
|
|
Aulopora
|
A. conferta
|
[5]
|
|
Also found in the
Bell,
Ferron Point,
Gravel Point, Genshaw,
Alpena,
Potter Farm, Petoskey and
Hungry Hollow formations.
|
|
A. gregaria
|
[5]
|
|
Also found in the
Genshaw Formation,
Alpena Limestone and Petoskey Formation.
|
|
Pachyphragma
|
P. concentricum
|
Dock Street clay member.
[5]
|
|
Also found in the
Ferron Point Formation,
Gravel Point Formation and
Alpena Limestone.
|
|
Gastropods
Sponges
Trilobites
See also
References
- ^
a
b
c
d
e
f
g
h
i Stack, Jack; Sallan, Lauren (2018-09-20).
"An examination of the Devonian fishes of Michigan". PeerJ. 6 (2).
doi:
10.7717/peerj.5636.
PMC
6151260.
- ^
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h
i
j
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aa Tyler, John H. (1965).
"Gastropods from the Middle Devonian Four Mile Dam Limestone (Hamilton) of Michigan". Journal of Paleontology. 39 (3): 341–349.
ISSN
0022-3360.
- ^
a
b
c
d
e Orr, R. William (1971).
"Conodonts from Middle Devonian Strata from the Michigan Basin".
- ^
a
b
c
d
e
f
g
h
i
j
k
l
m
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p
q
r
s Imbrie, John (1959).
"Brachiopods of the Traverse group (Devonian) of Michigan. Part 1, Dalmanellacea, Pentameracea, Strophomenacea, Orthotetacea, Chonetacea, and Productacea. Bulletin of the AMNH ; v. 116, article 4".
- ^
a
b
c
d
e Watkins, J. Lloyd (1959).
"Middle Devonian Auloporid Corals from the Traverse Group of Michigan". Journal of Paleontology. 33 (5): 793–808.
ISSN
0022-3360.
-
^ Tyler, John H. (1964).
"Anostylostroma anacolumna n. sp. from the Four Mile Dam Limestone (Hamilton), Alpena County, Michigan". Journal of Paleontology. 38 (5): 885–886.
ISSN
0022-3360.
- ^
a
b
c
d
e
f
g
h Stumm, Erwin (1953).
"Trilobites of the Devonian Traverse Group of Michigan" (PDF). University of Michigan Press - Museum of Paleontology.