The Pennsylvania State University The Graduate School College of Earth and Mineral Sciences THE CONTRIBUTION OF REGIONAL VARIABILITY TO BETA DIVERSITY: A CASE STUDY OF THE DEEP-WATER MARINE COMMUNITIES OF THE MIDDLE UPPER ORDOVICIAN OF EASTERN LAURENTIA A Thesis in Geosciences by Eriks Perkons ©2016 Eriks Perkons Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science May 2016 The thesis of Eriks Perkons was reviewed and approved* by the following: Mark E. Patzkowsky Associate Professor of Geosciences Thesis Adviser Peter D. Wilf Associate Professor of Geosciences Michael A. Arthur Professor of Geosciences Interim Associate Head for Graduate Programs and Research *Signatures are on file in the Graduate School ii ABSTRACT The structure and recurrence of marine invertebrate communities along depth gradients have been recent and productive research subjects among paleobiologists studying evolutionary patterns and biostratigraphic correlation. However, the extent to which these communities vary across regional spatial scales (beta diversity) has received comparatively little attention despite being a potential source for the observed increase in gamma diversity through the Paleozoic. The fauna of the middle Upper Ordovician Salona and Coburn Formations of the Trenton group carbonates were investigated to quantitatively study community compositions along a deep subtidal to offshore gradient. The deep subtidal through offshore biofacies have previously been under-sampled, so detailed examination of these strata provides much needed quantitative community data. High resolution (5 cm scale) stratigraphic analysis, coupled with extensive fossil collection from several exposures in central Pennsylvania, allows for identification of biofacies through cluster analysis, and faunal depth preferences through detrended correspondence analysis (DCA). These biofacies, and the ecologic preferences of their taxa, were then compared with previously reported collections from the Trenton Falls area of New York, and central Kentucky near Frankfort. While several comparable biofacies were identified, most did not have obvious counterparts in other collections. Those that were comparable varied greatly between locales, despite a high degree of taxonomic overlap. Ecological parameters of individual taxa were similarly not highly conserved, and all three locales contained numerous endemic taxa. Taxonomic dissimilarity between locations increases with greater geographic distance. Variations occurred over regional geographic scales, but not all correlate directly with distance, suggesting that regional and local variation may be a potential underappreciated source of diversity within provinces. iii TABLE OF CONTENTS LIST OF FIGURES ..................................................................................................................................... v LIST OF TABLES...................................................................................................................................... vi ACKNOWLEDGEMENTS ................................................................................................................... viii Chapter 1: Introduction ....................................................................................................................... 1 1.1 Significance and Objectives ........................................................................................... 1 1.2 Geologic History ................................................................................................................. 2 1.3 Trenton Group in Central Pennsylvania ................................................................... 5 1.4 Area of Investigation ........................................................................................................ 7 1.5 Correlation and Age Constraints .............................................................................. 10 Chapter 2: Data and Methods ......................................................................................................... 16 2.1 Collection and Counting Methodologies ................................................................ 16 2.2 Analytical Methods ........................................................................................................ 21 Chapter 3: Results ............................................................................................................................... 27 3.1 Lithofacies Descriptions .............................................................................................. 27 3.2 Cluster Analysis Results ............................................................................................... 36 3.3 Detrended Cluster Analysis Results ........................................................................ 42 Chapter 4: Discussion ........................................................................................................................ 49 4.1 Environmental Gradient .............................................................................................. 49 4.2 Ecological Gradient ........................................................................................................ 54 4.3 Additional Taxa ............................................................................................................... 59 4.4 Site Comparison .............................................................................................................. 65 4.5 Comparison Summary and Implications ............................................................... 85 Chapter 5: Conclusions ..................................................................................................................... 89 References .............................................................................................................................................. 91 Appendix A: Faunal Counts ............................................................................................................ 102 Appendix B: Stratigraphic Columns ............................................................................................ 104 Appendix C: Biofacies ....................................................................................................................... 111 Appendix D: Rarefaction and Species Accumulation Curves ........................................... 113 Appendix E: Faunal Lists ................................................................................................................. 115 Appendix F: Additional Photographs ......................................................................................... 117 iv LIST OF FIGURES Figure 1: Generalized stratigraphic section of Upper Ordovician strata of central Pennsylvania ...................................................................................................................... 4 Figure 2: Paleogeographic map of the study region ................................................................. 7 Figure 3: Locations of Pennsylvania outcrops ............................................................................ 9 Figure 4: Locations of Kentucky, New York, and Pennsylvania collections .................... 9 Figure 5: Correlation chart of Kentucky, Pennsylvania, and New York strata ............ 12 Figure 6: Reedsville outcrop panorama ..................................................................................... 17 Figure 7: Bedding of the upper New Enterprise Member at Reedsville ........................ 29 Figure 8: Idealized bedding pattern of the Laminated Mudstone and Packstone & Mudstone Facies .................................................................................................. 30 Figure 9: Bedding in the lower Roaring Spring Member at Reedsville .......................... 32 Figure 10: Stacked tempestite beds in Reedsville .................................................................. 33 Figure 11: General bedding of the Roaring Spring Member at Reedsville ................... 33 Figure 12: Bedding of the Coleville Member at Reedsville ................................................. 35 Figure 13: Amalgamated storm deposits at Reedsville ........................................................ 36 Figure 14: 2-way cluster analysis of faunal counts ................................................................ 38 Figure 15: Faunal log and DCA axis-1 scores of the Reedsville section ......................... 46 Figure 16: DCA axis-1 and axis-2 sample scores by geologic member .......................... 47 Figure 17: DCA axis-1 and axis-2 sample scores by biofacies ........................................... 47 Figure 18: Ecological parameters of Pennsylvania taxa ...................................................... 48 Figure 19: Microphotographs of Hexactinellid spicules ...................................................... 62 Figure 20: Microphotograph of macrotubular borings ........................................................ 64 Figure 21: Flow aligned fossils at Reedsville ........................................................................... 65 Figure 22: Jaccard dissimilarity for New York, Pennsylvania, and Kentucky collections ........................................................................................................................................ 77 Figure 23: DCA of Pennsylvania, Kentucky, and New York samples .............................. 78 v Figure 24: Correlation of ecological