Field Trip to the Ordovician of Indiana
(September 10, 2000)

Geology 250: Invertebrate Paleontology
(With your hosts, Mark A. Wilson & Aaron Shear)

Items to bring:
 
Notebook and pencils
Hand lens or other magnifying glass
Marking pen (indelible ink)
Raingear (if appropriate)
Geologic hammer (if you have one)
Canteen or water bottle (filled!)

At least it was dry in Wooster when we left at 6:00 a.m. The rains began shortly before the Indiana border, and they thoroughly soaked us even though we shifted our sites around to avoid it. Nevertheless, spirits remained very high and we brought back more fossils than any previous trip.

Where we went:

 
Yes, it is not quite the Rockies, but Colorado is a bit too far for us this year. The top left is a view of our first outcrop (Richmond); the top right is our second stop (Brookville North); the image on the bottom left is of our third stop (Bon Well Hill). The gray color is characteristic of the claystones and limestones of the Cincinnatian Group. Note that we don't have too far to walk for this kind of geology! These rocks are just loaded with fossils. You'll love the trip.

Some websites to visit for information on our rocks and fossils are: the Keck Ohio pages (from a summer project based in Wooster and ranging through northern Kentucky, southern Ohio and eastern Indiana); the Dry Dredgers page (by an extraordinarily keen amateur group of collectors with professional standards and excellent eyes for Cincinnatian fossils); the Cincinnati Geology course page of Dr. Richard Davis (which has a comprehensive bibliography on Cincinnatian paleontology); and the excellent set of pages on the Ordovician of Kentucky maintained by the Kentucky Geological Survey. You will also want to see, of course, the 1999 Wooster paleontology field project pages.

Driving schedule and directions:

6:00 a.m.: Leave Scovel Hall and proceed down Bever Street to its junction with U.S. Route 30. Travel west on U.S. 30 about 27 miles to Interstate 71. Take I-71 south. Stay on I-71 until the outskirts of Columbus, then take the by-pass (I-270) west toward Indiana. Continue on I-270 for about 17 miles, then exit onto westbound I-70 toward Indiana. Take I-70 all the way to Indiana, exiting about 7 miles past the border onto US 27 (Exit 151) and then proceeding south through Richmond. Drive approximately 6 miles south from the exit to a roadcut about one mile south of Richmond. The shoulder is narrow at the roadcut itself, so we will park beyond it where the shoulder widens just south of a driveway. This is Stop 1.

9:30 a.m.: Stop 1 -- Richmond Roadcut. The Whitewater Formation is exposed here. This is location C/W-148 in department records. (See description below.)

10:30 a.m.: Continue south on US 27 and for approximately 22 miles. At the town of Liberty, continue south on Indiana Route 101. Park along the roadside at the second set of large roadcuts on the southern side of the small valley the road intersects. This is Stop 2.

11:00 a.m.: Stop 2 -- Brookville North Roadcut. The Liberty Formation is exposed here. This is location C/W-149 in department records. (See description below.)

11:50 a.m.: Take Indiana Route 101 south for 4.1 miles. Park as far off the road as possible. This is Stop 3.

12:00 p.m.: Stop 3 -- Bon Well Hill section. The Arnheim and Waynesville Formations are exposed here. This is location C/W-111 in department records. (See description below.)

1:00 p.m.: Retrace our route back north to Richmond. (Before we get there we will find a place to eat a late lunch.) Return to I-70 in Richmond and head east towards Columbus. Then take I-270 north, I-71 north and finally US 30 east. We should be back in Wooster around 6:00 p.m., giving you enough time to get to a delicious Lowry dinner. Total miles driven: 471.

STOP 1: Richmond Roadcut
(C/W-148)

Here we can work in a superb exposure of the upper Whitewater Formation, near the top of the Cincinnatian Series. Note that shales are far less common here than in the previous sections. Common fossils at this outcrop include the following (references in parentheses are to the plate and figure numbers in the Davis Cincinnati Fossils book):

BRACHIOPODS --

Hebertella occidentalis (IV, 2-4, V, 24-25)
Platystrophia acutilirata (V, 1-5)
Platystrophia clarksvillensis (VII, 7-10)
Platystrophia cypha (VII, 11-14)
Holtedahlina sulcata (VIII, 25-26)
Rafinesquina sp. (I, 1-4)
Strophomena planumbona (VIII, 8-11)
Hiscobeccus capax (V, 7-9)
Rhynchotrema dentatum (V, 19-23)

BRYOZOA --

Ramose (branching) bryozoans (see IV, 14-16)
Massive bryozoans

CEPHALOPODS --

Orthoconic nautiloids (see I, 24-25 & VI, 8)

GASTROPODS --

Holopea sp. (II, 32)
Loxoplocus sp. (I, 18-19)

BIVALVES --

Ambonychia sp. (I, 11)
Ischyrodonta sp. (VIII, 12)
Caritodens demissa (I, 12 & V, 30)
Cyrtodontula umbonata (VIII, 13)
Anomalodonta gigantea (V, 31)

CNIDARIANS --

Protarea richmondensis (VI, 22-23)
Grewingkia canadensis (V, 6)

TRILOBITES --

Flexicalymene meeki (I, 22-23)
Isotelus sp. (I, 20-21)

OTHERS --

Oncolites (algal balls) in the upper portion.

 

STOP 2: Brookville North Section
(C/W-149)

These rocks contains at least five faunal assemblages, making them among the most fossiliferous limestones and shales in the world. You will note that the fossils change dramatically as we travel up section. Common fossils at this outcrop include the following (references in parentheses are to the plate and figure numbers in the Davis Cincinnati Fossils book):

BRACHIOPODS --

Glyptorthis insculpta (VIII, 1-4)
Hebertella occidentalis (IV, 2-4, V, 24-25)
Platystrophia moritura (VIII, 14-17)
Platystrophia acutilirata (V, 1-5)
Platystrophia clarksvillensis (VII, 7-10)
Platystrophia cypha (VII, 11-14)
Plaesiomys subquadrata (VIII, 5-7)
Onniella meeki (V, 32-35)
Leptaena richmondensis (V, 26-29)
Holtedahlina sulcata (VIII, 25-26)
Rafinesquina sp. (I, 1-4)
Strophomena planumbona (VIII, 8-11)
Strophomena vetusta (VIII, 23-24)
Sowerbyella rugosa (II, 14-16)
Hiscobeccus capax (V, 7-9)
Rhynchotrema dentatum (V, 19-23)
Zygospira modesta (I, 5 & III, 4)

BRYOZOA --

Batostomella gracilis (IV, 12-13 & VI, 19-20)
Ramose (branching) bryozoans (see IV, 14-16)

CEPHALOPODS --

Orthoconic nautiloids (see I, 24-25 & VI, 8)

GASTROPODS --

Loxoplocus bowdeni (I, 18-19)

BIVALVES --

Ambonychia sp. (I, 11)

CNIDARIANS --

Protaraea richmondensis (VI, 22-23)
Grewingkia canadensis (V, 6)

TRILOBITES --

Flexicalymene meeki (I, 22-23)
Isotelus sp. (I, 20-21)

OTHERS --

Tetradium approximatum (VIII, 18-20)

 

STOP 3: Bon Well Hill Section
(C/W-111)

This large roadcut shows a variety of lithologies within the Arnheim and Waynesville Formations. Note that some lithologies have abundant fossils, while others are almost barren. Be sure to look for trace fossils as well as the usual shells. Common fossils at this outcrop include the following (references in parentheses are to the plate and figure numbers in the Davis Cincinnati Fossils book):

BRACHIOPODS --
 
Hebertella sp. (IV, 2-4, V, 24-25)
Platystrophia clarksvillensis (VII, 7-10)
Retrorsirostra carleyi (VII, 5-6)
Onniella meeki (V, 32-35)
Leptaena richmondensis (V, 26-29)
Rafinesquina sp. (I, 1-4)
Strophomena planumbona (VIII, 8-11)
Sowerbyella rugosa (II, 14-16)
Zygospira modesta (I, 5 & III, 4)
Inarticulates (see IV, 10-11)

BRYOZOA --
 
Batostomella gracilis (IV, 12-13 & VI, 19-20)
Ramose (branching) bryozoans (see IV, 14-16)

GASTROPODS --
 
Cyclora and others (see page 26 of Davis)
Cyclonema sp. (V, 15-18)

BIVALVES --
 
Ambonychia sp. (I, 11)
Modiolopsis sp. (I, 13)
Ischyrodonta sp. (VIII, 12)

TRILOBITES --
 
Flexicalymene meeki (I, 22-23)
Isotelus sp. (I, 20-21)

OTHERS --
 
Crinoid fragments (I, 15)
Tentaculites richmondensis (VI, 14)
Conularia formosa (VI, 9)