1 University of Nevada, Reno Paleolimnology and Paleontology of the Miocene Quincy Diatomite Deposit A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Geology By Anthony Joseph Menicucci Dr. Paula J. Noble / Thesis Advisor August 2010 THE GRADUATE SCHOOL We recommend that the thesis prepared under our supervision by ANTHONY JOSEPH MENICUCCI entitled Paleolimnology and Paleontology of the Miocene Quincy Diatomite Deposit be accepted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Dr. Paula J Noble, Advisor Dr. Alan Wallace, Committee Member Dr. Mary Peacock, Graduate School Representative Marsha H. Read, Ph. D., Associate Dean, Graduate School i Abstract The Quincy Diatomite deposit, central Washington, USA, is a middle Miocene (~15 Ma) freshwater lacustrine deposit located between flows of the Columbia River Basalt Group. Three localities along the western margin of the deposit are examined and the diatom flora are described at the species level, with 84 species recognized. Of these species, one is new, Fragilariforma intortus, and one is elevated in rank to the species level, Tetracyclus williamsensii. One species, Pseudostaurosira brevistriata var. subcapitata, is also is transferred to a new genus for taxonomic clarification. Although rare, three species of the genus Sellaphora occur in the Quincy diatomite deposit, making this occurrence the oldest for the genus in the fossil record. The northwestern United States endemic fossil species Ellerbeckia baileyi is also observed in the deposit, and is abundant in particular stratigraphic intervals. Stratigraphic and geographic variation within the deposit is also examined. The three lithologic units recognized in the deposit, the Four Crude, Bottom Crude, and Top Crude, are distinguished by subtle lithologic differences and contain distinct diatom floras. Textural properties are largely a function of floral differences between units. Diatom assemblages also vary geographically along the western margin of the basin particularly between localities of Top Crude in northern outcrops of the Ancient Lakes Park versus more southerly localities in the Frenchman Hills and Gorge Amphitheater. Distinctions between these assemblages are confirmed through analysis of point count data using nonMetric Multidimensional Scaling and cluster analyses. ii Some species within the flora, primarily Aulacoseira granulata and Staurosira construens var. venter, are used as ecologic proxies to interpret the paleolimnology of the Ancient Quincy Lake as an alkaline, eutrophic to hypereutrophic lake with high Total Phosphorus (TP), and sufficient dissolved Silica (Si) levels capable of sustaining a large phytoplankton population. Three stages of development in lake ecology, directly influenced by the regional geology and geography, are recognized. The earliest stage, represented by the Four Crude, was deposited in a series of small-interconnected pocket lakes that were monomictic, eutrophic, slightly alkaline, and had a depth of greater than 15 meters. This lake stage was succeeded by Bottom Crude deposition and is interpreted to represent the period of maximum shallowing, creating a polymictic lake of less than 10 meters depth and dominated by benthic species. The latest stage of the lake, represented by the Top Crude, represents the deepest and broadest expansion of the lake and shows variable development of lake stratification through its deposition. Tectonic uplift of the western Frenchman Hills Anticline combined with overall subsidence of the Quincy Basin during intermediate and late stages of lake development is interpreted to be the driver for changes in lake bathymetry. iii Acknowledgments This work would not have been possible if it were not for the assistance and support of several people, I owe a great debt to all who have helped me in this endeavor. I’d like to thank the Nevada Petroleum Society for their grant awards for the 2007 and 2008 years and the Paleontological Society for their 2007 grant. I would also like to thank my advisor, Paula Noble, for her help and assistance during this undertaking; she taught me to write like a scientist, and had endless patience for my ambition, helping me to focus my efforts and develop this work. My committee, Alan Wallace and Mary Peacock area also due a great deal of thanks for their consultations as I progressed through the project. Many thanks go to World Minerals inc. and Mike Houseman and the United States Army Corps of Engineers for access to materials and all their assistance both in the field and the lab; this work would not have been possible without their help. I’d also like to thank my family for all their support and encouragement through the entire process. Many thanks go to my wife Nichole, for her support and willingness to put up with me through this undertaking, and her support as I progress in my professional and academic careers. Finally, all the people at Iowa Lakeside Laboratory, including Sarah Spaulding, Mark Edlund, and Steve Juggins for their consultation and teaching efforts; thank you all. iv Table of Contents Abstract i Acknowledgements iii Table of Contents iv List of Tables vii List of Figures viii Chapter 1: Paleolimnology and Paleontology of the Quincy Diatomite I. Introduction 1 II. Regional Geology 6 III. Methods 16 IV. Observations 21 V. Limnologic Interpretations 40 VI. Summary and Conclusions 58 Chapter 2: Systematics and Species Descriptions with rare species list I. Systematics (by Genus) a. Aulacoseira 62 b. Melosira 66 c. Actinocyclus 67 d. Ellerbeckia 70 e. Diatoma 72 f. Fragilaria 75 g. Fragilariforma 78 h. Staurosirella 80 v i. Meridion 83 j. Pseudostaurosira 84 k. Staurosira 86 l. Synedra 88 m. Tetracyclus 89 n. Eunotia 96 o. Cavinula 99 p. Neidium 100 q. Sellaphora 101 r. Pinnularia 102 s. Diploneis 104 t. Navicula 105 u. Cymbella 107 v. Placoneis 109 w. Gomphonema 112 x. Gomphosphenia 117 y. Planothidium 118 z. Nitzschia 122 aa. Extremely Rare Species List 124 II. References 126 III. Plates #1-23 140 vi APENDICES a. Appendix 1– Sample numbers and Sampled Cores 186 b. Appendix 2– Specimen Picture X-Y coordinates 191 c. Appendix 3– Point Count Data 197 d. Appendix 4–Error Calculation Counts 206 e. Appendix 5– Measurements of Width for Grain Size Calculation 217 f. Appendix 6– Extended Methodologies 227 g. Appendix 7 – Organic Carbon Test Results 236 h. Extended Bibliography – Includes References used but not cited 238 vii LIST OF TABLES 1. Table 1: UTM Coordinates for all sample sites 17 2. Table 2: Species Occurrence list/Key to species for NMDS 35 viii LIST OF FIGURES 1. Figure 1: Locality Map of the Quincy Diatomite deposit 4 2. Figure 2: Stratigraphy of the Columbia River Basalts 9 3. Figure 3: Stratigraphy of the Quincy Diatomite deposit 11 4. Figure 4: Relative Abundance Stratigraphic Plot: Frenchman Hills 23 5: Figure 5: Relative Abundance Stratigraphic Plot: Ancient Lakes Park 29 6: Figure 6: NMDS Plot of Species and Samples 33 7: Figure 7: Cluster Analysis – Wards Method of Samples 39 8: Figure 8: Modeled Extent of Quincy Ancient Lake 55 1 Chapter 1: Paleolimnology and Paleontology of the Quincy Diatomite deposit I. Introduction The Quincy Diatomite deposit is a Miocene lacustrine deposit that occurs within the Columbia River Basalt Group in central Washington. This deposit is located in the Quincy Basin in the northern part of the Yakima Fold Belt (Figure 1). The diatomite is industrial grade and hyper pure (> 90% pure diatom material), and it has been actively mined for the last 50 years in several localities, primarily in and around the Frenchman Hills area. Although some work has been published on the Quincy flora, no one has comprehensively studied the species composition and floral variation either stratigraphically or geographically. Vanlandingham (1964, 1967) studied Miocene diatoms from the central Washington area including some small outcrops to the south of the Frenchman Hills (Figure 1A). His study broadly detailed the floral assemblages of the entire central Washington region through multiple time periods in the Miocene, but specific characterization of the Quincy flora and interpretation of its ecology was left for future research. Kociolek and Spaulding (2002) examined material from the northern areas of the deposit (Figure 1A) in their paper where they suggested the possibility of a single species with multiple morphologies expressed as Ellerbeckia sp. and Actinocyclus sp.. However, their study was topical in nature and the entire flora was not described. Houseman (2006) reported some preliminary data on relative abundance counts, primarily at the genus level. His findings showed stratigraphic variation at the genus level, and illustrated fundamental differences between each of the three units within the 2 Quincy Diatomite deposit. Houseman’s findings indicated further investigation of the Quincy flora should provide useful paleolimnological data. The Quincy Diatomite deposit holds particular significance because the extremely good diatom preservation provides great potential to aid in understanding geologic and paleolimnologic influences in a Miocene diatomite-bearing basin. Such basins exist commonly in the Western US (Lohman, 1957, Bradbury and Krebs, 1995, Bolm et al., 2003), yet little work has been done to characterize whole assemblages at the species- level and then use any observed changes in paleolimnological reconstructions of diatomites. Further, the Quincy deposit