GEOLOGIC AND HYDROLOGIC CONTROLS ON SPRING, STREAM, AND GROUND WATER CHEMISTRY IN THE BIG CHICO CREEK WATERSHED AND BUTTE BASIN, CALIFORNIA A Thesis Presented to the Faculty of California State University, Chico In Partial Fulfillment of the Requirements for the Degree Master of Science in Environmental Sciences by © Carol Lynn Perkins 2013 Spring 2013 GEOLOGIC AND HYDROLOGIC CONTROLS ON SPRING, STREAM, AND GROUND WATER CHEMISTRY IN THE BIG CHICO CREEK WATERSHED AND BUTTE BASIN, CALIFORNIA A Thesis by Carol Lynn Perkins Spring 2013 APPROVED BY THE DEAN OF GRADUATE STUDIES AND VICE PROVOST FOR RESEARCH: ______________________________ Eun K. Park, Ph.D. APPROVED BY THE GRADUATE ADVISORY COMMITTEE: ______________________________ William M. Murphy, Ph.D., Chair ______________________________ David L. Brown, Ph.D. ______________________________ Paul Maslin, Ph.D. PUBLICATION RIGHTS No portion of this thesis may be reprinted or reproduced in any manner unacceptable to the usual copyright restrictions without the written permission of the author. iii DEDICATION I dedicate this project and resulting interim discoveries to the Big Chico Creek Ecological Reserve and the following individuals instrumental in key phases of this study. Dr. Paul Maslin, field scientist extraordinaire – without your prior fieldwork this particular project would never have lifted off the ground. Paul’s knowledge of the natural environment at the Reserve is second to none. I’m indebted to you for discovering and making accessible the springs in the BCCER, hosting exhilarating field excursions and for your keen handling of the “Amphibian.” I appreciate your willingness to share your insights about the geology and hydrology of the Reserve and for your wisdom regarding everything in the canyon. Dr. William Murphy – a remarkable advisor and a genuinely good individual. Dr. Murphy is a consummate geoscientist, and I am fortunate to have had the opportunity to study under his guidance. Bill worked tirelessly to help me narrow my ever-wandering questions and tease out meaningful perspectives about natural processes occurring throughout a watershed and the myriad water-rock-gas reactions that can take place along a flow path. And, finally to frame those thoughts into constructive points that culminated in this thesis. Bill taught me to think critically and express myself succinctly; skills I will continue to hone as my knowledge of aqueous geochemistry expands and as opportunities arise to share with the scientific community. Bill’s motivation turned a daunting task into an enriching endeavor. iv ACKNOWLEDGMENTS This journey has been blessed with the development of gracious partnerships and peer mentoring that I will carry with me into all future endeavors. Of course, behind each student is a network of mentors. I realize I’m no exception, but I also realize that my network is exceptional: filled with exceptional people. I cannot thank those who have walked along this path with me enough. While many endeavors in life are personal experiences, there are those out there who have a way of providing just the right words or manna of support when needed. First, my family: immediate and extended – my husband and three boys have endured and encouraged and are the impetus behind my intellectual pursuits. These four gentlemen are truly the wind beneath my wings. My incredible parents, who lent their spare bedroom as an office away from home; and who greeted me daily with love and a smile and cheered me on. I followed your footsteps mom. My in-laws lovingly add a new dimension to ‘the village’ when it comes to help in ‘raising’ my children. Thanks to my sisters Linda and Dana for sharing wisdom in life and all pursuits we engage therein. I am deeply grateful for all of you. Second, I’d like to thank my committee for their patience, time, and expertise (current members, past, and those who served in-between). I’ve recognized Drs. Murphy and Maslin earlier. Dr. Dave Brown encouraged me to think from the micro-scale (what is the pore-water pressure?) to the macro-scale (why do fens exist in this particular place in the watershed?). Your faculty taught me to think critically regarding hydrology, geology, and modeling. v Ron Cook, who by fate of an intriguing connection to mining and a consequential relationship with his incredible wife Lucy, willingly waded through an utterly awful first draft and provided key questions and suggestions that supplied the proverbial ‘light at the end of the tunnel.’ The author wishes to express her appreciation to Jennifer Lara, the rock on which the Geological and Environmental Sciences department rests. Thanks for always being there when a little extra boost was needed and for your help navigating through the final months of this endeavor. My deepest thanks go to the following individuals and programs for their financial backing and support of this project: Jeff Mott (Director of Ecological Reserves); the California State University, Chico Institute for Sustainable Development, and Dr. Flory (Geological and Environmental Sciences department chair, CSUC in 2005 when this study launched). And finally, I cannot pass this opportunity to thank in perpetuity all the local water wonks I have the pleasure to engage with daily. Your individual strengths and perspectives enrich my life and this experience. I endeavor to return in-kind some small percentage of all I’ve gained from these relationships. The printing of this tome brings to an end the metaphorical ‘nickel’ well. vi TABLE OF CONTENTS PAGE Publication Rights ........................................................................................................... iii Dedication ........................................................................................................................ iv Acknowledgments ........................................................................................................... v List of Tables ................................................................................................................... x List of Figures .................................................................................................................. xi Abstract ............................................................................................................................ xiii CHAPTER I. Introduction ................................................................................................. 1 Big Chico Creek Watershed ........................................................... 1 Two Essential Supplies .................................................................. 6 Ecological Importance of Big Chico Creek ................................... 8 Characterization – An Important First Step ................................... 9 Objectives of this Study ................................................................. 10 II. Background and Physical Setting ............................................................... 12 Literature Review ........................................................................... 12 The Hydrogeologic Setting ............................................................ 17 Geomorphic Units .......................................................................... 20 Geology .......................................................................................... 23 vii CHAPTER PAGE III. Spring Descriptions and Data Sources ....................................................... 28 Introduction to Spring Data ............................................................ 28 Tuscan Formation Springs ............................................................. 30 Chico Formation Springs ............................................................... 34 Unclassified Springs ....................................................................... 37 Reported Chemical Data: Big Chico Creek ................................... 39 Reported Chemical Data: Ground Water ....................................... 39 Reported Chemical Data: Precipitation ......................................... 40 IV. Methodology ............................................................................................... 41 Introduction .................................................................................... 41 Spring Hydrochemical Data ........................................................... 41 Numerical and Graphical Methods ................................................ 47 Mixing Models for Stream and Ground Water .............................. 50 Selection of Representative End Members .................................... 52 EQ3 Speciation Analysis ................................................................ 53 V. Results and Interpretation ........................................................................... 54 Introduction .................................................................................... 54 New Data: Big Chico Creek Springs ............................................. 55 Spring Hydrochemical Data: Tuscan Formation ........................... 57 Spring Hydrochemical Data: Chico Formation ............................. 64 Unclassified Springs ....................................................................... 70 Fluoride Concentrations ................................................................. 73 Analysis of Field Parameters ......................................................... 73 Introduction to Published Data ...................................................... 75 Reported