Western Washington University Western CEDAR WWU Graduate School Collection WWU Graduate and Undergraduate Scholarship Spring 1992 Late Pleistocene Deglaciation History at Point Partridge, Central Whidbey Island, Washington Cynthia A. Carlstad Western Washington University Follow this and additional works at: https://cedar.wwu.edu/wwuet Part of the Geology Commons Recommended Citation Carlstad, Cynthia A., "Late Pleistocene Deglaciation History at Point Partridge, Central Whidbey Island, Washington" (1992). WWU Graduate School Collection. 789. https://cedar.wwu.edu/wwuet/789 This Masters Thesis is brought to you for free and open access by the WWU Graduate and Undergraduate Scholarship at Western CEDAR. It has been accepted for inclusion in WWU Graduate School Collection by an authorized administrator of Western CEDAR. For more information, please contact [email protected]. LATE PLEISTOCENE DEGLACIATION HISTORY AT POINT PARTRDIGE, CENTRAL WHIDBEY ISLAND, WASHINGTON by Cynthia A. Carlstad Accepted in Partial Com'{!>letion of the Requirements for the Degree Master of Science Dean of Graduate Scho< Advisory Committee MASTER’S THESIS In presenting this thesis in partial fulfillment of therequirements for a master’s degree at Western Washington University, I agree that the Library shall make Its copies freely available for inspection. I further agree that extensive copying of this thesis is allowable only for scholarly purposes. It is understood, however, that anv copying or public ation of this thesis for commercial purposes, or for financial gain, shall not be allowed without mv written permission-. MASTER'S THESIS In presenting this thesis in partial fulfiliment of the requirements for a master's degree at Western Washington University, 1 grant to Western Washington University the non-exclusive royalty-free right to archive, reproduce, distribute, and display the thesis in any and all forms, including electronic format, via any digital library mechanisms maintained by WWU. I represent and warrant this is my original work and does not infringe or violate any rights of others. I warrant that I have obtained written permissions from the owner of any third party copyrighted materiai included in these files. I acknowledge that I retain ownership rights to the copyright of this work, including but not limited to the right to use all or part of this work in future works, such as articles or books. Library users are granted permission for individual, research and non-commercial reproduction of this work for educationai purposes only. Any further digital posting of this document requires specific permission from the author. Any copying or publication of this thesis for commercial purposes, or for financial gain, is not allowed without my written permission. Name: Signature: CxI lA-VUC C(X\T 1 Date: LATE PLEISTOCENE DEGLACIATION HISTORY AT POINT PARTRIDGE, CENTRAL WHIDBEY ISLAND, WASHINGTON A Thesis Presented to the Faculty of Western Washington University In Partial Fulfillment of the Requirements for the Degree Master of Science by Cynthia A. Caristad June 1992 ABSTRACT The study area contains a record of deglaciation events that has not been recognized elsewhere in the Puget Lowland. This record includes both subaerial outwash and glaciomarine deposition. The geologic history of the study area during recession of the Vashon ice sheet is marked by the following events: (1) deposition of a kame delta complex from grounded ice probably located in Penn Cove and west of Point Partridge. This delta complex was built into marine water with a sea-level at approximately 55 meters. Eventually, ice drained by the outwash streams stagnated in the Point Partridge kettle region. (2) Isostatic rebound of the depressed land surface caused relative sea-level to drop as the ice continued to become thinner. (3) Deposition of sand and gravel from outwash streams ceased as the ice continued to thin and eventually floated, depositing glaciomarine drift below approximately 37 meters. Narrow marine terraces were carved into Vashon till and Partridge outwash around the perimeter of Penn Cove. In addition to these events, the relationship between the Partridge outwash and Everson glaciomarine drift is described. Partridge outwash is an Everson Interstade unit, deposited by meltwater streams in a marine environment. ACKNOWLEDGMENTS First and foremost, I want to thank Don Easterbrook, chair of my advisory committee. Through the years that I have known Don, his friendship, wisdom and encouragement have greatly impacted the choices I have made in my life. Chris Suczek and Derek Booth, my other advisors, also desenre special thanks for their valuable guidance and suggestions regarding this project. Chris’s encouragement and general positive attitude have helped keep me moving. Derek agreed to join my advisory committee after the project was underway, and his enthusiasm and perspective shaped this thesis in many ways. One of the greatest side-benefits for me in writing this thesis was becoming better acquainted with all of you. Ma ny Geology folks have helped me with this project through technical assistance and friendship. George Mustoe, Chris Sutton, Vicki Critchlow, and Patty Combs deserve special mention. This thesis was partially funded through a Geology Department grant and through a Washington Department of Natural Resources contract. Thanks to Hank Schasse of WDNR for help with the WDNR contract. My employer, ENSR Consulting and Engineering, has been supportive of me in this academic endeavor. Many thanks also to my colleagues at ENSR who have individually offered encouragement and worked around my school schedule during the last several months. ii Because I have taken seven years to complete this degree, many people along theway have reminded me of the importance of completing it. In particular I want to thank my family for all their love and moral support. Last but not least, my gratitude goes out to my husband Bret, who, over the course of this project, has truly demonstrated the power of a life-partner. Ill CONTENTS 1.0 INTRODUCTION ........................................................................................................ 1-1 1.1 Pleistocene History of the Puget Lowland ........................................................ 1-1 1.2 Statement of Problem......................................................................................... 1-8 2.0 METHODOLOGY AND APPROACH.......................................................................... 2-1 2.1 Methods............................................................................................................... 2-1 2.1.1 Map and Air-Photo Interpretation.......................................................... 2-1 2.1.2 Geologic Mapping ................................................................................ 2-1 2.1.2.1 Well Logs ............................................................................... 2-2 2.2 Approach ............................................................................................................. 2-3 2.2.1 Dating and Correlation ......................................................................... 2-3 2.2.2 Reconnaissance Mapping in Related Regions .................................... 2-4 2.2.3 Comparison of Study Results to Existing Knowledge about Final Deglaciation in the Puget Lowland ........................................................ 2-5 3.0 GENERAL SETTING .................................................................................................. 3-1 3.1 Physical and Climatological Setting................................................................... 3-1 3.2 General Geologic Framework ............................................................................ 3-2 4.0 PREVIOUS WORK...................................................................................................... 4-1 5. 0 STRATIGRAPHY, SEDIMENTOLOGY, AND MORPHOLOGY.................................. 5-1 5.1 Double Bluff Drift ................................................................................................ 5-1 5.1.1 Description............................................................................................. 5-1 5.1.2 Distribution and Stratigraphic Relationships.................... 5-3 5.1.3 Age........................................................................................................ 5-5 5. 2 Whidbey Formation ........................................................................................... 5-5 5.2.1 Description............................................................................................. 5-5 5.2 .2 Distribution and Stratigraphic Relationships........................................ 5-6 5.2 .3 Age and Correlation.............................................................................. 5-9 5.3 Vashon Drift.......................................................................................................... 5-9 5.3.1 Esperance sand .................................................................................. 5-12 5.3.1.1 Description ........................................................................... 5-12 5.3 .1.2 Distribution and Stratigraphic Relationships...................... 5-12 5.3 .1.3 Age and Correlation............................................................. 5-13 5.3.2 Vashon Till and Associated Drift ........................................................ 5-15 iv CONTENTS (Cont’d) 5.3.2.1 Description and Origin .......................................................