OREGON GEOLOGY Oregon Department of Geology and Mineral Industries Volume 62, Number 4, October 2000 IN THIS ISSUE: Springs in the Oregon Cascades Oil and gas exploration and development in Oregon, 1999 K-Ar results from the southern Oregon-northern California Cascade Range Seymour appointed to DOGAMI Governing Board Barbara Ann Proebstel Seymour retirement in 1997. The Seymours’ of Salem was appointed by Gover- three children all live in Oregon and nor John Kitzhaber and confirmed have given them eight grandchildren. by the Oregon Senate at the end of Seymour has a story to tell about June to serve as Governing Board the beginning of her contact with member of the Oregon Department DOGAMI. We’ll give you her own of Geology and Mineral Industries words: “I was interested in mining (DOGAMI). She succeeds Arleen N. as my grandfather was in mining Barnett of Portland. In addition to camps as a hardware man and my Seymour, the three-member Board grandmother taught school in mining includes Donald W. Christensen of camps. Although they were deceased Depoe Bay, the current chair, and before I was born, I inherited an in- Vera E. Simonton of Pendleton. terest in mining and mining history Seymour was born in Baker City, from my Dad. When my daughter’s Oregon. Her father, Robert I. Proeb- mother-in-law, Marian Mack, want- stel, was general manager of the Barbara Ann Proebstel Seymour ed to look into the Sampson Mine at general store in Cornucopia at the Baker City, and Pendleton, and re- Sumpter because her grandfather was time of her birth. The region experi- ceived degrees in law from the Uni- a blacksmith for the Sampson Mining enced much gold mining activity at versity of Oregon. After she and her Company, I went in [to the DOGAMI that time, so she calls herself “a gold husband had practiced law together Baker City field office —ed] to locate mining child.” in Florence, Oregon, the family the mine. There I met a very knowl- She grew up mostly on the fami- moved to Salem in 1964. Here, Bar- edgeable lady, Jan Durflinger, who ly’s ranch in Haines in northwest Ba- bara Seymour worked in the Office helped me locate the mine, one of ker County, went to school in Haines, of the Legislative Counsel until her (Continued on page 122) The Nature of the Northwest Information Center: Suite 177, 800 OREGON GEOLOGY NE Oregon St. # 5, Portland, OR 97232-2162, phone (503) 872- (ISSN 0164-3304) 2750, FAX (503) 731-4066 Internet: http://www.naturenw.org VOLUME 62, NUMBER 4 OCTOBER 2000 Donald J. Haines, Manager. Published quarterly in Winter, Spring, Summer, and Fall by the Oregon Department of Geology and Mineral Industries. (Volumes 1 through 40 were entitled The Ore Bin.) Periodicals postage paid at Portland, Oregon. Subscription rates: 1 year, $10; 3 years, $22. Single issues, $3. Governing Board Address subscription orders, renewals, and changes of address to Ore- Donald W. Christensen, Chair . Depoe Bay gon Geology, Suite 965, 800 NE Oregon Street # 28, Portland 97232. Vera E. Simonton. Pendleton Barbara P. Seymour . Salem POSTMASTER: Send address changes to Oregon Geology, Suite 965, 800 NE Oregon St. # 28, Portland, OR 97232-2162. State Geologist . John D. Beaulieu Deputy State Geologist . Dennis L. Olmstead Permission is granted to reprint information contained herein. Editor . Klaus K.E. Neuendorf Credit given to the Oregon Department of Geology and Mineral In- Production Assistants . Kate Halstead, James Roddey dustries for compiling this information will be appreciated. Main Office: Suite 965, 800 NE Oregon Street # 28, Portland 97232, phone (503) 731-4100, FAX (503) 731-4066. Internet: http://sarvis.dogami.state.or.us Baker City Field Office: 1510 Campbell Street, Baker City 97814, Cover photo phone (541) 523-3133, FAX (541) 523-5992. Please note new Metolius River, originating between Three Fin- Mark L. Ferns, Regional Geologist. street address! gered Jack and Santiam Pass on the eastern slope of Coastal Field Office: 313 SW Second Street, Suite D, Newport 97365, phone (541) 574-6642, FAX (541) 265-5241. the central Oregon High Cascades, is the best known George R. Priest, Coastal Team Leader. example of the large-volume discharges of ground- Grants Pass Field Office: 5375 Monument Drive, Grants Pass 97526, water found in the region. The head of the Metolius phone (541) 476-2496, FAX (541) 474-3158. emerges from the ground as a full-size river. The ar- Thomas J. Wiley, Regional Geologist. ticle beginning on the next page discusses age and Mined Land Reclamation Program: 1536 Queen Ave. SE, Albany provenance of some of the waters that are supplied 97321, phone (541) 967-2039, FAX (541) 967-2075. by the Cascade Range mountains. Photo no. A-823 Internet: http://www.proaxis.com/~dogami/mlrweb.shtml Gary W. Lynch, Supervisor. by Oregon Department of Transportation. 86 OREGON GEOLOGY, VOLUME 62, NUMBER 4, OCTOBER 2000 Springs in the Oregon Cascades: Where does the water come from? And how old is it? by Elizabeth R. James and Michael Manga, Department of Geological Sciences, University of Oregon, Eugene, Oregon 97403, and Timothy P. Rose, Analytical and Nuclear Chemistry Division, Lawrence Livermore Nation- al Laboratory, Livermore, California 94550 ABSTRACT how natural isotopic tracer measure- the subsurface geology. Isotopic and temperature meas- ments and temperature measure- Where did the water come from? urements from large, cold springs in ments of spring water can be used How old is the water? These are two the central Oregon Cascades are to study both the hydrology of the of the most commonly asked ques- used to understand where this area (Figure 2) and some aspects of tions about the hydrogeology of groundwater comes from and how old it is. In particular, we employ the isotopes of helium, carbon, oxygen, and hydrogen to address these is- sues and to understand some as- pects of the subsurface geology in this region. We find that large, cold springs in the central Oregon Cas- cades are recharged near the Cas- cades crest up to 50 km from the springs. We also find that the large springs in the study area discharge water that is a few years old. Finally, we show that deeply circulating groundwater advectively transports geothermal heat and magmatic volatiles to several of the springs such as the Metolius River and Lower Opal Springs. INTRODUCTION Surface water is a valuable re- source to the east of the High Cas- cades. Rapid population growth in Deschutes County over the last 25 years has placed heavy demands on available surface water resources in the region (Caldwell, 1998). From Mount Jefferson in Oregon south to Lassen Peak in California, cold springs discharge groundwater in high volume, providing much of the base flow to regional rivers. Some of these springs are so large that they emerge from the ground as mature rivers, and as such, they are ar- guably among the most scenic spots in the region (Figure 1). Aside from their aesthetic value, however, the springs also provide a unique way of learning about regional hydrogeolo- gy. The goal of this paper is to show Figure 1. Fall River, central Oregon. OREGON GEOLOGY, VOLUME 62, NUMBER 4, OCTOBER 2000 87 springs. Isotopic tracers present in unique way of studying the subsur- dominated by the Cascade arc, the water can be used to elucidate face geology. which began to form 40 million both of these questions. After dis- years ago as the Farralon Plate sub- cussing some background informa- GEOLOGIC AND HYDROLOGIC ducted beneath the North American tion, we describe how tracers and SETTING plate (Orr and Orr, 1996). Starting temperature measurements can be Local hydrology is determined in around 7.5 million years ago, the used to address the two questions large part by local geology. In cen- line of eruptive centers shifted east- posed above, as well as provide a tral Oregon, the local geology is ward and the belt of active volcan- 122 o 00' 121 o 00' 45 00' o o 45 00' N. Santiam Oregon Mt. JeffersonL Metolius Metolius Hd. Three-fingered JackL LBlack Butte Lower Opal Mt. Washington L Sisters Squaw Crooked Belknap Crater L × × Redmond McKenzie L Three Sisters L 44 00' L Broken Top L × Bend o o Tumalo Mt. Bachelor L 44 00' Snow Spring Cr. Fork Willamette Cultus 0 20 40 Quinn Fall North kilometers Browns Davis Deschutes Deschutes Cascade Crest Springs Little Metolius gauginggaging station 122 o 00' 121 o 00' Figure 2. Map of the study region, showing locations of springs discussed in this paper. 88 OREGON GEOLOGY, VOLUME 62, NUMBER 4, OCTOBER 2000 ism narrowed to the location of the Quaternary volcanic rocks, most of a snow pack may occur through modern High Cascades. From 7.5 to rivers and streams are fed by large- cycles of freezing and thawing, but 5 million years ago, the Cascades volume springs that discharge cold for this analysis we assume that the volcanoes extruded large volumes of water, while thermal springs are rel- isotopic composition of the snow- basalt and basaltic andesite lava. The atively scarce (Meinzer, 1927). These melt is approximately the same Deschutes Formation to the east of spring-fed streams are characterized when it infiltrates the ground. If we the modern crest of the High Cas- by relatively constant discharge know the relationship between ele- cades is a remnant of this volcanic throughout the year, with peak vation and isotopic composition of episode. During this period, the tec- flows only several times larger than precipitation, we can estimate the tonic regime changed from a com- base-flow (Whiting and Stamm, mean recharge elevation of a spring pressional to an extensional one, 1995).