One of the "backbones" of geology is field study. You can learn a lot more in the field in an hour than you can in an hour of class. Therefore, for your final field project you will be studying the Ordovician limestones (Carters Ls and Bigby-Cannon Ls) and mixed carbonate/siliciclastic rocks (Hermitage Fm) along TN route 70S (John Bragg Highway) at Cannon County mile markers ~2.8 ("Carson Fork") or 4.0 (Hollis Creek) a few miles west of Woodbury. Your task is to accurately and thoroughly describe your section; your primary objective is to identify and interpret the cause of sedimentological (and hence environmental) changes through time (e.g. variations and trends in bedding type and thickness, carbonate allochem character, siliciclastic content, fossil and ichnofossil abundance and diversity, and physical sedimentary structures).

Each of you will be assigned a ~ 4 to 5+ meter stratigraphic interval to study and interpret. (However, if a couple of you wish to choose an outcrop on your own, we can meet individually to assess whether your choice is suitable.) You must measure, describe, sample and photograph the outcrop. With these materials, you will prepare an interpretation of your stratigraphic interval, along with a detailed stratigraphic section.

The field time involved will vary from individual to individual but it should require no more than 6 to 8 hours to complete the field work. You may prepare carbonate peels or polished hand samples of the rocks if you wish, but this is not required.

There is a general format -- outlined below -- that you must use to present your project. You will present your outcrop analysis in the form of an informal talk in the last schedule lab meeting of the semester. Your presentation should consist of a discussion of the geologic setting, a description of the outcrop, your interpretation of the depositional environment, and your supporting evidence, as well as any alternate hypotheses. A summary of this in paper form will be due on the last day of classes.

Together, the activities relating to the field project total 35 points or about 15% of your grade. These points are distributed as follows: 5 pts. = class presentation; 10 pts. = one page summary plus stratigraphic column; 20 pts. = field skills as indicated below. Projects submitted after the last day of classes will be considered late. Each day that the project is late, 10% (3.5 points) will be deducted from the final score. Any student who does not submit the completed project by the day of the final exam will: (a) receive an incomplete for the class, (b) be required to submit a more detailed (five page) report along with the project. Together the report and project will then only be worth a total of 20 points toward the final grade.

You MUST turn in your neat, legible field notebook (or clear photocopies) on or before the last day of class. I will assess your efforts at that time. Numbers 4, 6 & 9 must also be submitted at the same time. To receive full credit you must properly:

1. measure your outcrop using both brunton & staff methods (2 pts.)
2. describe & sketch overall outcrop geometry & character (2 pts.)
3. make a field sketch of the outcrop (2 pts.)
4. photograph outcrop features at various scales using digital camera & field scale (2 pts.)
5. sample outcrop at appropriate interval(s) (2 pts.)
6. correctly mark samples with coded labels for identification and geographic/geologic orientation (2 pts.)
7. petrologically describe a genetically related vertical sequence of hand samples & interpret EOD (3 pts.)
8. describe & assign facies/depositional units to outcrop (2 pt.)
9. computer draft (at least titles & labels) a descriptive section of the outcrop (3 pts.)

1. Locate stratigraphic section (outcrop) on a topographic/geologic quadrangle¹
2. Determine section's latitude and longitude¹
3. Name section using a named, geographic map feature in close proximity¹
4. Measure section & any covered intervals²
5. Sample outcrop
6. Photograph study interval and representative features³
7. Determine section's stratigraphic level (stratigraphic interval)¹

1. Outcrop scale description
2. Bed scale description
3. Describe sedimentary structures (including ichnofossils) bed by bed
4. Describe rock type(s) and textures bed by bed
5. Describe bedding contacts
6. Describe hand samples
7. Prepare and describe thin sections/acetate peels & hand samples⁴

1. Determine sedimentary "packages" (i.e. depositional units)
2. Perform thin section point counts⁴

1. Interpret hand samples (and polished sections or peels)⁴
2. Interpret rock type(s), rock textures, and sedimentary structures (including ichnofossils)
3. Decide on an environment of deposition (EOD) with appropriate subenvironments
4. Develop a depositional model (e.g. discuss larger scale processes that caused (a) bioturbation to decrease or (b) siliciclastic influx to increase or (c) an increase in storm frequency).

1. Prepare an explanatory stratigraphic column⁵ (interval thickness, bedding thickness, rock types, facies descriptions, sedimentary structures, depositional processes, & EOD; you may use this form as a guide)
2. Present your depositional model orally, and provide a one page written summary (the summary is due on the last day of class)
3. Turn in written summary, stratigraphic column⁵, and a table of detailed facies descriptions keyed to your stratigraphic column

1. Participate in class discussion aimed at integrating sections into a mutually acceptable, regional depositional model

This project is intended to serve as a model of graduate work. Graduate students often discuss their work with one another and gain insights from fellow students. I urge you to discuss your field observations and interpretations with others in the class, and to help each other with field work. However, certain restrictions apply.

You are not allowed to discuss your section with anyone who is interpreting the same stratigraphic interval nor can you work with them in the field. Your work MUST be independent. Likewise, do NOT confer with other faculty members. However, feel free to ask me about any aspect of your project or for help with your interpretation. I especially urge you to discuss your hand samples with me, as well as your field observations. Do NOT use published interpretations of these outcrops as your own -- I consider that a form academic dishonesty ("cheating") which is a violation of MTSU's code of student conduct.

Do not bring rock samples into the department assuming that you can "donate" them at the end of the semester; we're covered up with excess rocks as it is and I'm tired of lugging them out to the dumpster. This is intended to be a field project, NOT a lab project so at most you might want to collect small hand samples for later description. You can then dispose of them after you turn in your project.

Finally, you may visit any of the outcrops in the area to see a greater diversity of features, but your measured section should be based on the location you were assigned.

(a) Carson Fork section consists of units 1 - 5 and is located on TN70S in Cannon Co., 2.8 miles east of the Rutherford Co./Cannon Co. line. The north outcrop consists of 4 faces (units 1-5; latter is not complete), separated by 3 continuous benches. The south outcrop has only three faces (i.e. it lacks units 5-8).

(b) Hollis Creek section consists of units 1 - 8 and is located on TN70S in Cannon Co., at mile marker 4, 4.0 miles east of the Rutherford Co./Cannon Co. line. The south outcrop consists of six faces, separated by five benches. The north outcrop has only three faces, and two benches. The latter provides the only exposure of the Bigby-Cannon and better access to much of the Hermitage.

Bigby-Cannon Limestone (thickness ~ 30 meters)

Unit 8: Dove-colored Ls [Hollis Creek (south outcrop only)]

Limestone, medium-light gray to medium-gray, weathers to light-gray, micritic to fine-grained, medium-bedded, evenly bedded, brittle, conchoidal fracture, specks and stringers of clear calcite. Thickness & interval locally variable (overlap w/units above and below for a total thickness > 4 meters)

Unit 7: Cannon Ls [Hollis Creek (south outcrop only)]

Limestone, medium-dark gray and dark gray to brownish-gray, micritic to medium-grained, medium-bedded, evenly bedded. Thickness 25 to 30 meters; only lower 5.5 meters assigned.

Hermitage Fm (thickness ~ 25 meters)

Unit 6: Silty nodular Ls [Carson Fork (N outcrop only) & Hollis Creek (S outcrop only)]

Argillaceous limestone, medium-gray, thin-bedded, nodular and shaley. Thickness 5+ meters

Unit 5: Granular phosphatic Ls [Carson Fork (N o/c only) & Hollis Creek (S o/c only)]

Calcarenite to calcirudite, medium-light gray to brownish gray, medium- to thick-bedded, cross-bedded, contains brown, phosphatic pellets. Thickness locally variable, 0.3 to 3 meters. (overlap w/units above and below for a total thickness > 4m)

Unit 4: Laminated argillaceous Ls [Carson Fork & Hollis Creek outcrops]

Silty to sandy limestone, medium- to dark-gray, weathers pale and dark yellowish-brown. Very fine- to medium-grained, thin-bedded to laminated with thin shale partings; shale interbeds may be present as well as hard, silty thin or medium beds with abundant shells of the pelecypod Ctenodonta on bedding surfaces. Thickness ~5.5 meters.

Unit 3: Curdsville Ls [Carson Fork (above 2nd large, continuous bench) & Hollis Creek]

Interbedded shale and limestone, medium- to dark-gray, fine- to coarse-grained, thin-bedded with thin shale partings to medium-bedded, fossiliferous. Thickness ~ 4+ meters.

Carters Ls (thickness 25+/- meters)

Unit 2: Upper member [Carson Fork & Hollis Creek outcrops]

Limestone, medium-light gray to brownish-gray, olive-gray and yellowish-brown, variable: micritic, argillaceous, with some beds ranging up to coarse-grained; generally laminated to thin-bedded with thin shale partings or zones. Thickness 4 to 4.5 meters.

T-3 bentonite [begins above first large bench]: shale, pale-green when fresh, weathers to white and yellow sticky clay; rarely exposed in outcrop, commonly overlies a thin bed of brown chert. Thickness 0.15 to 0.4 meters.

Unit 1: Lower member [Carson Fork & Hollis Creek outcrops]

Limestone, medium-light gray to brownish-gray and yellowish-brown, variable: generally micritic to fine-grained with some beds ranging up to coarse-grained; graded and rippled bedding common, generally medium- to thick-bedded. Thickness 25 to 30 meters; only upper 5.5 meters assigned.

Carson Fork section, MM 2.8, Cannon County;  Units 1 to 4 (5 not complete; Ocr-Ohm)	Hollis Creek section, MM 4.0, Cannon County	Hollis Creek section,  Units 1 to 4 (Ocr-Ohm)	Hollis Creek section,  Units 2 to 4 (Ocr-Ohm)
Hollis Creek section,  Units 2 to 4 (Ocr-Ohm)	Hollis Creek section (SE corner),  Units 2 to 4 (Ocr-Ohm)	Hollis Creek section (South face),  Units 2 to 4 (Ocr-Ohm)	Hollis Creek section (South face),  Units 4 & 5 (Ohm)
Hollis Creek section (South face),  Units 4 to 8 (Ohm-Obc)	Hollis Creek section (South face),  Units 4 to 6 (Ohm)	Hollis Creek section (South face),  Units 4 to 6 (Ohm)	Hollis Creek section (South face),  Units 4 to 8 (Ohm-Obc)