Timing of the uplift of the Cincinnati Arch: A hypothesis-driven field-based paleontology term project

This field-based term project is completed as part of an undergraduate course: Paleontology, which is an upper-division geology course that is required for the major. Approximately half of the course focuses on paleontological concepts and techniques (e.g., fossilization, biozones, biostratigraphic correlation, evolutionary principles) and half focuses on major invertebrate taxa and their identification (e.g., brachiopods, bryozoans, cephalopods, corals, etc.). The course typically enrolls junior- and senior-level geology majors and occasional environmental science majors or biology majors.

Students should have familiarity in the identification of major Paleozoic fossil taxa, including brachiopods, bryozoans, crinoids, gastropods, nautiloids, rugose and tabulate corals, and trilobites. Students also should have experience constructing taxon range charts (assemblage biozone) and paleonvironmental matrices. All of these skills are developed as part of the laboratory component of this course.

This exercise is completed as a field-based culminating project. The field event during which students collect their fossil samples is completed following the sixth week of the semester. The field event occurs earlier in the semester (early October) to take advantage of more favorable weather conditions. Prior to the field event, one lecture session introduced the background setting and project hypothesis, as well as a description of the general types of fossils they will collect. Upon return from the field event, one lecture session details how they will process, identify, and analyze their fossil data and how they will use these data to test the project hypothesis. Fossil identification and analysis is completed during the final three laboratory sessions of the semester. Students present their results during the final lecture session of the semester and a written report is due on the last day of the semester, prior to the final exam week.

This project provides: (1) experience identifying common Paleozoic invertebrate fossil taxa to the phylum and/or specie level, (2) additional experience constructing taxon range (assemblage biozone) charts to interpret the age of a fossil assemblage, (3) additional experience constructing paleoenvironmental matrices to interpret the depositional environment represented by a fossil assemblage, (4) experience using their fossil data to test a project hypothesis and communicate their results in both verbal (presentation) and written (report) form.

This project develops higher order thinking skills by requiring the students to test a project hypothesis using fossil samples and resultant data from samples they collected during a field event. The project hypothesis is provided to them as part of the project background data. Because each student will have slightly to potentially significantly different sample suites, depending on what they collected during the field trip, they will not necessarily have the same data/results. Therefore, each student is forced to interpret their data individually and reach their own conclusions.

As part of the fossil identification process, students use a fossil guidebook ("Ohio Fossils" [LaRocque and Marple, 1970]) as well as other instructor-approved internet resources to identify their fossil samples to the genus and/or specie level. Following fossil identification, students search the Paleobiology Database (paleobiodb.org) to determine age and paleonvironmental data for their specimens. Students present their project results and interpretations in both verbal (presentation) and written (report) form.

This project uses fossil samples collected during a class field trip to test the project hypothesis: "The Cincinnati Arch was a structural high during the Late Ordovician, where water depth was shallowest along the axis of the arch and deepened away from the axis". Fossils are collected and identified from two sites in the Cincinnati, OH area. Collection site one (Caesar Creek State Park, OH) is located near the axis of the Cincinnati Arch. Collection site two (road cut along US-127, approx. 3.5 miles south of Camden, OH) is located west of the arch axis. Students determine the age of the strata at each site from age data for their fossils (obtained from the Paleobiology Database) and by constructing assemblage biozone charts. The age data are used to interpret if the sites are comparable in age, therefore useful for testing the project hypothesis. Depositional environments for each site are interpreted from their paleoenvironmental matrices (constructed using data also from the Paleobiology Database), which is used to interpret water depth during deposition at each site, thereby providing then the ability to interpret if the Cincinnati Arch was a actively uplifting structure during the time that the site strata were deposited.
Student Project Instructions (Microsoft Word 2007 (.docx) 26kB Aug11 22) 
Field Trip Guidebook (Microsoft Word 2007 (.docx) 1.4MB Aug11 22) 
Fossil Identification and Analysis Lectures (PowerPoint 2007 (.pptx) 48.5MB Aug11 22) 

Instructors Paleoenvironmental Data Table_ALL Taxa -- educator-only file

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Students should be provided with a lecture and discussion covering the general geologic background of the Cincinnati Arch and what types of fossils they are likely to encounter during the field trip. Students should additionally be provided with lecture and discussion covering how they will use their fossil specimens to test the project hypothesis, including discussion of how to use the "Ohio Fossils" guidebook and the Paleobiology Database. I have provided my fossil identification and data interpretation lectures in a single file.

I encourage my students to have washed and pre-sorted their samples prior to meeting for the first laboratory session dedicated to the project. During the project-dedicated laboratory sessions, I provide my students paper cups that they can use to further sort and organize their fossil specimens upon identification.

The copy of "Ohio Fossils" used for this project is an older, out-of-print guidebook from the Ohio Department of Natural resources (1970 printing). It is available as a free download from the Ohio DNR website (link included below in the "Resources" section of this page). The current version of the guidebook is "Fossils of Ohio" (Ohio DNR Bulletin 70 [1996]). I continue to use the 1970 "Ohio Fossils" version because (1) it is freely available to my students and (2) it is a more simplified version of the guidebook, which I find is easier for students to use. I bring a copy of the current (1996) version to the project laboratory sessions for students to access, if desired, because it contains high quality images of specimens as opposed to the less detailed drawings of specimens included in the 1970 version of the guidebook.

Prior to the Fall 2021 semester, I had my students access age and paleoenvironmental data from the Paleobiology Database via the Fossilworks gateway portal (fossilworks.org). The Fossilworks portal was an excellent and user-friendly way to obtain age data and all documented paleoenvironments for a given taxon in a single data page. Unfortunately, during the middle of the Fall 2021 semester, something happened to the Fossilworks portal where it ceased to function properly and Is no longer (as of July 2022) able to connect to and access the Paleobiology Database. The result is that students must now directly access the Paleobiology Database (paleobiodb.org) to obtain age information. I have provided instructions for how to access this age information from the Paleobiology Database within my data analysis lecture. Paleoenvironment data can also be obtained from the Paleobiology Database, but it must be extracted from 10s to 100s of know occurrence localities for each taxon. This is not practical for this project. The Fossilworks portal previously automated this process of extracting and compiling paleoenvironmental data. My Fall 2021 solution to this problem was to use the master paleoenvironmental data table that I have compiled over several years of running this field trip. This master data table was compiled for all specimens that I have collected and identified from the two sites combined. Instead of having the students search the database for paleoenvironmental data, once they have made their fossil identifications, I had them provide me a list of their identified fossils and I provided them a list of paleoenvironments documented for each taxon. I do not provide them a copy of my master paleoenvironmental data table. They only receive data for those taxa that they have identified and requested. In the event that they identified something that is not in my master list, then those data will simply not be available to them. This solution worked well the last time the course was taught (Fall 2021) and did not cause any problems with the project. I have included my master paleonvironmental data table (essentially an answer key to fossil identifications) with access available to verified educators in the "Supporting Materials" section of the project webpage.

Notes on fossil collection at location one (Caesar Creek State Park): A fossil collection permit (free) must be obtained from the Visitor Center prior to collection. The collection site is located in the dam spillway. Restrooms and water are available at the Visitor Center. Additional information regarding the collection site, including collection restrictions, is available at the following url:

https://www.lrl.usace.army.mil/Missions/Civil-Works/Recreation/Lakes/Caesar-Creek-Lake/Fossil-Collecting/

Notes on fossil collection at location two (US-127): There are numerous road cuts to choose from along US-127 in the area a few miles south of Camden, OH. The road cuts at approximately 3.5 miles south of Camden are the ones that I have consistently used for this project. Fossil productivity tends to be best on the eastbound side of the highway, where the road cuts are higher and steeper. Fossils can easily be collected from float occurring on the lower several feet of the roadcut; climbing is not required. There are several wide pull-outs at this location on the westbound side of the highway. Both sides of the highway have ample space for pedestrians to be a safe distance from traffic. Please beware and warn students of vehicle traffic. The speed limit along this stretch of highway is 50 or 55 mph. Restrooms are available at various gas stations approximately 3.5 miles north in Camden, OH.

Directions to the collection locations, with maps and figures/photos are provided in my included class field trip guidebook.

There are other fossil collection sites in the vicinity of Cincinnati, OH that could be used to expand on this project. I have been to a few of them but the two included here are by far the best and most productive sites in the area that I have visited.

Students meeting the goals for this exercise will have: (1) correctly identified their fossil specimens; (2) successfully constructed an assemblage biozone chart and accurately interpreted the age of the strata for each collection site; (3) successfully constructed a paleoenvironmental matrix and accurately interpreted the depositional setting of the strata for each collection site; (4) drawn reasonable conclusions as related to the project hypothesis; (5) successfully presented their data and interpretations to the class; and (6) submitted a complete, accurate, and professionally prepared project report.

"Ohio Fossils" is the fossil identification guidebook used for this project. A full and free downloadable copy of the guidebook is available from the Ohio DNR website.
https://ohiodnr.gov/static/documents/geology/B54_LaRocque_1970.pdf
Citation: LaRocque, A. and Marple, M., 1970, Ohio Fossils: State of Ohio Department of Natural Resources, Division of Geological Survey Bulletin 54, 152 p.

The Paleobiology Database is used for age determinations of identified fossils.
https://paleobiodb.org

The Fossilworks portal to the Paleobiology Datbase was previously used for age determination and paleoenvironmental data of identified fossils.
Note: As discussed in the teaching notes, this portal went offline during the Fall 2021 semester and remains offline as of July 2022. If this portal remains offline when a user attempts future access, then paleoenvironmental data for the project can be obtained from my included master paleonvironmental data table, which is available to verified educators in the "Supporting Materials" section of this project page.
http://fossilworks.org

The UGA Stratigraphy Lab is an additional website that can be used for assisting in identifying fossils from the Cincinnati, OH region. This website is particularly useful for identifying two species of crinoids found at the collection sites (and potentially other taxa) that are not detailed in the "Ohio Fossils" guidebook. Photographs are available on the website for many of the included taxa.
http://strata.uga.edu/cincy/index.html