ABSTRACT OF THE THESIS OF LaVerneDuane Kulm for the Doctor of Philosophy in Oceanography (Name) (Degree) (Major) Date thesis is presented:C Title SEDIMENTSOF(YAIJINATh,OREGON Abstract approved: Signature redacted for privacy. (Major Prufessor) Three realms of depositi.n, Marine,luviatile, and Marine- Fluviatile, are recognized in Yaquina Bay, Oregon, on the basis of sediment texture and mineralogy.The Marine Realm extends 1. 5 miles into the entrance of the estuary and is typified by normal marine salinity and vigorous tidal action.Sediments of this realm are similar to those of the adjacent beach and coastal dune sands and consist of well-sorted, subangular to subrounded, fine to medi- um sand.The immature arkosic sands in this realm are disting- uished by the marine suite of heavy minerals which include abundant pyroxenes, primarily hypersthene and diopside, and such metamor- phic minerals as kyanite, sillimanite, and staurolite.The Fluviatile Realm occurs at the fresh-water head of the estuary and reaches to a point 6 miles from the entrance, where brackish water conditions prevail.The poorly sorted, angular to subangular sedi- ments of this realm range in grain size from silt to coarse sand. They are somewhat more arkosic than the sands of the Marine Realm and are represented by the fluviatile suite of heavy minerals. This assemblage includes such diagnostic minerals as biotite and muscovite, and hematite and limonite.Diopside is absent, hyper- sthene is restricted, and there is a marked decrease in the abund- ance of garnet and the number of metamorphic species, compared with the Marine Realm.The Marine-Fluviatile Realm lies between the Fluviatile and Marine Realms and contains admixtures of sedi- ments of the other two realms. The chief sources of Recent sediments in the Yaquina Bay area are the Tertiary rocks of the central Oregon Coast Range, the Pleistocene marine terrace sands and estuarine deposits near the bay mouth, and the Recent transitory beach and dune sands that flank the bay entrance. Marine sand from the adjacent ocean beaches is transported into the estuary by strong tidal currents to Oneatta Point 6 miles from the entrance.Nearby coastal dune sands are blown into the tidal channel near the mouth of the estuary and onto the southwest- ern shore of Southbeach Tidal Flat by strong onshore winds.Sus- pended sediments are contributed by the Yaquina River during per- iods of high runoff. The type of estuarine system is dependent upon seasonal and annual climatic conditions.Generally, from June to October the system is well-mixed, but it may alternate between a well-mixed to partly-mixed system from November to May.Precipitation re- corded at Newport apparently reflects the type of estuarine system present during each month of the year for any given year. Deposition in Yaquina Bay appears to be largely seasonal. Maximum deposition probably occurs in the winter and early spring when river runoff is highest, the littoral drift is from south to north, and the highest velocity winds are from the southwest.At this time, the partly-mixed estuarine system is effective in trans- porting drifting beach sands into the entrance of the estuary.Dur- ing the summer, deposition is slight because of the low runoff, southward littoral drift, and northwest winds.The well-mixed es- tuarine system inhibits the transportation of sediments into the estuary. Known areas of shoaling occur on the bar, in the main chan- nel, and in the turning basin.The shoaled areas have maintained a fairly constant position from 1950 to1961. Estimated average rate of deposition in the dredged channel is 9. 1 inches per year.Marine sand is the principal shoaling material.As a result of jetty con- struction in 1888, and through subsequent additions, extensive deposition has occurred on the southern ocean beach behind the south jetty.An average estimate of Z74 cubic yards of material accumulated annually during the past 73 years. SEDIMENTS OF YAQUINA BAY, OREGON by LAVERNE DUANE KULM A THESIS submitted to OREGON STATE UNIVERSITY in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY June 1965 ACKNOWLEDGMENTS This study was made possible through the financial support of the Office of Naval Research (Contract Nonr 1286(10)) and the laboratory facilities of the Department of Oceanography, Oregon State University.The writer wishes to express his sincere appre- ciation to Neil Maloney, Douglas Manske, and Donald Rosenberg who contributed their time and efforts to the field sampling program. Several agencies are gratefully acknowledged for donating data used in this manuscript; these include the U. S. Coast and Geodetic Survey, the U. S. Army Corps of Engineers (Portland District), and the U. S. Bureau of Mines (Albany, Oregon). The author is deeply indebted to his major professor, Dr. John V. Byrne, for aiding in the field, critically reviewing several drafts of the manuscript, and assisting in the preparation of the photographic plates.His guidance and inspiration throughout the investigation are gratefully acknowledged. Special thanks go to Dr. Herbert F. Frolander for supplying the author with timely unpublished hydrographic data collected under his supervision in Yaquina Bay and to Dr. Bruce McAlister for invaluable unpublished hydrographic records of previous sur- veys. Informal discussions with fellow students Neil Maloney, who added much knowledge to the study, Donald Rosenberg, and David Bushnell were especially helpful in analyzing the data and preparing the report.Many other friends and colleagues freely gave their encouragement and advice. Sincere appreciation is expressed to doctors Jon C. Cummings, Bruce McAlister, Kilho Park, and June G. Pattullo who kindly read the manuscript or portions of it, and made many helpful suggestions in all phases of the study. Finally, the author wishes to express his sincere apprecia tion to his wife, Sally, who spent many long hours typing several drafts of the manuscript and drafting many of the figures contained herein. SEDIMENTS OF YAQUINA :BAY, OREGON TABLE OF CONTENTS Page Introduction 1 Geography 2 General 4 Climate General Physiography and Areal Geology Geomorphology General 9 Yaquina Bay 10 Bathymetry 11 Drainage 15 Beaches and Dunes 1 8 Physical Oceanography and CliniaticContro1 2 1 Classification of Estuarine Types 2 1 Relation of Hydrography to Climate 23 Seasonal Circulation Patterns 25 Climatic Control 27 Salinity, Temperature, and Dissolved Oxygen Measurements 30 Currents 34 Yaquina Estuary 34 Page Littoral Drift 36 Sediments 40 Sampling and Treatment of Samples 40 Field Methods 40 Sediment Analyses 42 Texture.. 44 Grain Size . .. 44 Sorting and Skewness 47 Roundness 50 Surface Texture 52 Composition . 53 Organically Produced Material 54 Calcareous Material 54 Organic Material 56 Inorganically Produced Material 60 Light Minerals 60 Feldspar and Quartz 6 1 tIyj Grains" 63 Rock Fragments .. 64 Glauconite 65 Heavy Minerals 65 Concentration and Distribution 65 Page Heavy Mineral Suites 68 Environments of Deposition 71 Beach 71 Lower Foreshore 72 Texture 72 Mineralogy 73 Upper Foreshore 77 Texture 78 Mineralogy 79 Dune 79 General 79 Texture 80 Mineralogy 80 Estuary 81 Channel 81 Texture 82 Mineralogy 86 Oxidized Sediment 94 Tidal Flats and Sloughs 96 Texture.. .. 96 Mineralogy .. 97 Tidal Flat Processes ... 101 Page Depositional History 108 Southbeach Tidal Flat 110 Sallys Tidal Flat 116 Summary of Depositional Environments 120 Beach 120 Dune 121 Estuary 122 Sources of Sediments 1 25 Fluviatile .. 1 25 Marine 131 Processes of Transportation and Deposition 1 35 Sites of Deposition 1 35 Shoreline 1 35 South Ocean Beach 1 35 Rate of Deposition 1 38 Yaquina Bay 1 38 Basin-Channel-Bar 1 38 Rate of Deposition 1 43 Seasonal Fluctuations in Transportation and Deposition. 1 43 Conclusions 147 Bibliography 152 Appendix I 157 Page Appendix 2 163 Appendix 3 169 LIST OF FIGURES Fig. Page Index map of study area 3 Stratigraphic section at Yaquina Bay 8 Bathymetry of Yaquina Bay (1868) 1 3 Bathymetry of Yaquina Bay (1953) 14 Drainage basin of Yaquina River 1 6 Coastal dunes 20 7 Salinity difference between surface and bottom waters 26 Correlation between precipitation and salinity 28 Salinity, temperature, and oxygen measurements. ... 33 Directions of wave advance due to Sea and Swell 38 Sample locations 41 1 2. Distribution of phi median diameters 45 1 3. Distribution of sediment types in Yaquina Bay 48 1 4. Distribution of calcium carbonate in Yaquina Bay 55 15. Shell accumulations in an intertidal channel 57 1 6. Distribution of the percentage of heavy minerals 66 1 7. Relationship between "yellow grains" and rock fragments in beach sands 74 Fig. Page 1 8. Heavy mineral profile of ocean beaches 76 1 9. Distribution of phi median diameters across estuary channel 84 20. Relationship of "yellow grains" and rock fragments in Yaquina Bay 88 2 1. Heavy mineral profile in Yaquina estuary 9 1 Heavy mineral profile across tidal flats 100 Shallow intertidal channel cutting across tidal flat. .. 103 Ephemeral submarine delta 104 Meandering intertidal channels. 105 Clumps of algae controlling meandering intertidal channels 106 Eel grass inhibiting erosion 107. Burrows and Mound on tidal flat 109 Core (YB-89) from Southbeach Tidal Flat 111 Core (YB-90) from Southbeach Tidal Flat 112 Clam producing beds in Yaquina Bay 114 Core (YB-87) from Sallys Tidal Flat 117 Core (YB-85) from Sallys Tidal Flat 118 Realms of deposition in Yaquina Bay 123 Nearshore and shoreline development from 1868 to 1953 136