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A Morphological and Geochemical Investigation of Grypania Spiralis: Implications for Early Earth Evolution

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A Morphological and Geochemical Investigation of Grypania Spiralis: Implications for Early Earth Evolution University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Masters Theses Graduate School 8-2010 A Morphological and Geochemical Investigation of Grypania spiralis: Implications for Early Earth Evolution Miles Anthony Henderson University of Tennessee - Knoxville, [email protected] Follow this and additional works at: https://trace.tennessee.edu/utk_gradthes Part of the Biogeochemistry Commons, Geochemistry Commons, Paleobiology Commons, and the Paleontology Commons Recommended Citation Henderson, Miles Anthony, "A Morphological and Geochemical Investigation of Grypania spiralis: Implications for Early Earth Evolution. " Master's Thesis, University of Tennessee, 2010. https://trace.tennessee.edu/utk_gradthes/715 This Thesis is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Masters Theses by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a thesis written by Miles Anthony Henderson entitled "A Morphological and Geochemical Investigation of Grypania spiralis: Implications for Early Earth Evolution." I have examined the final electronic copy of this thesis for form and content and recommend that it be accepted in partial fulfillment of the equirr ements for the degree of Master of Science, with a major in Geology. Linda C. Kah, Major Professor We have read this thesis and recommend its acceptance: Christopher M. Fedo, David B. Finkelstein Accepted for the Council: Carolyn R. Hodges Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) To the Graduate Council: I am submitting herewith a thesis written by Miles Anthony Henderson entitled “A Morphological and Geochemical Investigation of Grypania spiralis: Implications for Early Earth Evolution.” I have examined the final electronic copy of this thesis for form and content and recommend that it be accepted in partial fulfillment of the requirements for the degree of Master of Science, with a major in Geology. Linda C. Kah, Major Professor We have read this thesis and recommend its acceptance: Christopher M. Fedo David B. Finkelstein Accepted for the Council: Carolyn R. Hodges Vice Provost and Dean of the Graduate School A Morphologic and Geochemical Investigation of Grypania spiralis: Implications for Early Earth Evolution A Thesis Presented for the Master of Science Degree The University of Tennessee, Knoxville Miles Anthony Henderson August 2010 Acknowledgments First, I would like to thank Vibhuti Rai (University of Lucknow, India), Tian Lifu (Hebei College of Geology, China), James St. John (Ohio State University), Hans Hofmann (McGill University, Canada), and Julie Bartley (Gustavus Adolphus College) for donating samples for this study, and Shuhai Xiao (Virginia Polytechnic University) for mediating the transfer of samples from China. I would also like to thank Monty and Mary-Ellen Schnur, who graciously provided access to the Greyson Shale fossil locality – your generosity toward generations of geologists has not gone unnoticed. Thank you as well to the various agencies that have financially supported this research: the Belt Association, Sigma Xi, Geological Society of America Southeastern Section, and the Society for Sedimentary Geology (SEPM). Finally, thanks to the University of West Georgia Microscopy Center (Julie Bartley), the University of Tennessee organic geochemistry laboratories (Dave Finkelstein), the University of Tennessee palynological laboratories (Sally Horn), and the High Temperature Materials Laboratory at Oak Ridge National Laboratory (Ed Kenik) for access to facilities and their support in operating analytical equipment. Finally, I thank my wife, Viktoria, without whose support I would not have been able to complete this thesis research. ii Dedication This thesis is dedicated to the late Hans Hoffman, whose untimely death in May 2010 will be felt by many. May the degree of dedication with which Hans approached difficult questions regarding Proterozoic fossils and dubiofossils be a lesson to us all. iii Abstract Macroscopic “carbonaceous” fossils such as Grypania, Katnia, Chuaria, and Tawuia play a critical role in our understanding of biological evolution in the Precambrian and their environmental implications. Unfortunately, understanding of these fossils remains limited by their relative simplicity of form, mode of preservation, and broad taphonomic variability. As a result, debate continues as to even the fundamental taxonomic affinity of the organisms. Megascopic coiled forms (i.e. Grypania and Katnia), for instance, have been interpreted as trace fossils, multicellular algae, prokaryotic filaments, macroscopic bacteria, cyanobacteria, or a transitional form from macroscopic to megascopic bacterial life. Similarly, Chuaria and Tawuia have been interpreted as compressed prokaryotic colonies, algae or algal reproductive stages, and multicellular plant material. Accessibility of new material and increasingly sophisticated means of analysis warrant a new look at these ancient fossils. Understanding the biological affinity of Grypania, in particular, is critical because current opinion is split as to whether these megascopic structures are more likely represent either multicellular bacteria or multicellular algae. Confirmation of either a bacterial or algal affinity would strongly influence fundamental understanding of biospheric evolution, particularly in terms of ocean oxygenation and the availability of bioessential trace metals. Although estimates for the degree of oxygenation required for a Grypania-like multicellular algae are only about 10 % present atmospheric levels (PAL), this estimate is still substantially higher than estimates based on geochemical data suggesting that oxygen levels may not have reached 10% PAL until the latter Neoproterozoic. It has been hypothesized that protracted oxygen of the Proterozoic biosphere may have played a critical role in the availability of redox-sensitive nutrients necessary for bacterial nitrogen fixation and the limiting of eukaryotic evolution. Within this context, our understanding of the taxonomic affinity of Grypania may profoundly affect our understanding of Earth’s biospheric evolution. This thesis provides morphological and geochemical analyses of Grypania spiralis from more than 100 newly collected specimens from the Belt Supergroup for comparison to previously collected specimens from all other known Grypania-bearing localities. Data is used to explore questions regarding the morphology, structural complexity, mode of preservation, and chemistry of fossil material, and to hypothesize on the taxonomic affinity of Grypania spiralis and its implications for biospheric evolution. iv Table of Contents 1. Introduction................................................................................................................................. 1 2. Historical Context of Grypania Studies ...................................................................................... 3 3. Materials and Methods................................................................................................................ 6 3.1 Sample Localities.................................................................................................................. 6 3.1.1 Greyson Shale – Belt Supergroup.................................................................................. 6 3.1.2 Gaoyuzhuang Formation – Changcheng System......................................................... 10 3.1.3 Rohtas Formation – Vindhyan Supergroup ................................................................. 10 3.1.4 Negaunee Iron Formation – Marquette Range............................................................. 11 3.2 Analytical Methods............................................................................................................. 11 3.2.1 Sample Collection........................................................................................................ 11 3.2.2 Morphological Characterization .................................................................................. 14 3.2.3 In Situ Geochemical Characterization ......................................................................... 16 3.2.4 Ultrastructural Characterization................................................................................... 17 3.2.5 Biochemical Characterization...................................................................................... 18 4. Results and Interpretation ......................................................................................................... 19 4.1 Reconstruction of Grypania Morphology........................................................................... 19 4.1.1 Morphologic and Taphonomic Characterization……………………………………..19 4.1.2 Morphological Interpretation....................................................................................... 30 4.2 Mode of Preservation.......................................................................................................... 32 4.2.1 Environmental Scanning Electron Microscopy – Secondary Electron Mode ............. 32 4.2.2 Environmental Scanning Electron Microscopy – Backscatter Electron Mode........... .35 4.2.3 X-Ray Energy Dispersive Analysis (EDS).................................................................
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