Yellowstone - A Geothermal Wonderland A GRC Fieldtrip led by Duncan Foley and Roy Mink

Half the world’s geysers! 10,000 The specific plans for each day may be thermal features! Bubbling mud pots! modified to accommodate various interests A restless caldera! expressed by trip participants and changes GRC Fieldtrip: Thursday September 28 - Sunday encouraged by geological events, such as October 1, 2017 unanticipated geyser eruptions. We may experience Join the GRC on a trip of a lifetime to a wide range of weather conditions, from sunny experience the wide range of hydrothermal and warm to cold, wet and snowy. Old Faithful features in Yellowstone immediately before the is at an elevation of about 7,300 feet (or slightly GRC Annual Meeting. Our focus will be on surface more than 2,200 meters), so our walks will offer an manifestations of hydrothermal systems, what is option for a pace suitable to accommodate those known about their subterranean plumbing, and from lower elevations. We will be walking on how the systems fit into their geologic and volcanic improved trails and boardwalks throughout our contexts. Yellowstone has a unique concentration of trip. Participants need to be prepared for inclement heat, water, and geologic structures, which allows weather, but do not need to be prepared for off-trail us to experience the world’s greatest concentration or backcountry trekking. of geysers, mud pots and hot springs. The trip will be over four days, leaving mid- Thursday, September 28 morning on Thursday September 28 and returning • We leave Salt Lake City mid-morning to Salt Lake City in time for the Sunday night GRC/ on Thursday to start our drive to West GEA Opening Reception on October 1. We plan to Yellowstone, Montana. As we drive north travel by luxury bus, and include stops on our way along highway I-15, we will point out to and from Yellowstone. A tentative itinerary is important geologic and geothermal features described below. along the Wasatch Fault, the Wasatch Mountain Range, and the Great Salt Lake. 32 GRC Bulletin l www.geothermal.org Panoramic view of Norris Geyser Basin. Joe Moore, June 2015.

• Our first geologic stop will be south of Idaho Falls. Here we will discuss the geology of the Plain, the sequence of buried calderas that marks the plain, and have the chance to walk along improved trails through a several thousand-year-old basalt flow. We leave the interstate at Idaho Falls, and drive toward West Yellowstone.

Mesa Falls. PHOTO BY ROY MINK

• After the falls, we will head to West Yellowstone where we will settle into our motel for the next two nights, and enjoy the local cuisine (Buffalo Burgers anyone?!).

Tour leader Duncan Foley explains the geology of the Snake River plain on a GRC Fieldtrip in 2015. PHOTO BY IAN CRAWFORD • We plan to stop at Mesa Falls, a scenic waterfall along the Henry’s Fork River. We will continue our discussion of calderas while we are at the waterfall, as the rocks here mark the second of three major super-volcano eruptions The Three Bears Lodge in West Yellowstone. COURTESY THREE that compose the Yellowstone volcanic field. BEARS LODGE

May/June 2017 33 Friday and Saturday, September 29 • Norris Geyser Basin – This geyser basin and 30 features highly dynamic thermal systems, We will spend most of Friday and Saturday which tap some of the deepest and hottest exploring geothermal and geologic features of waters in the park. Norris Geyser Basin is Yellowstone. Our travels will emphasize the located where an old fault zone intersects the geology and hydrothermal features that are margin of the Yellowstone Caldera and where within or immediately adjacent to the Yellowstone the zones are kept permeable by seismic Caldera. At each stop, we will review the local activity. Geysers at Norris erupt at intervals geological and geophysical environments ranging from a few minutes to several and introduce trip participants to important decades. It’s impossible to predict which of hydrothermal features. The geochemical data will these geysers will erupt during our visit. This be used to infer what might be happening in the area also has unusual acidic waters in some of subsurface. We will describe results from recently- its geysers and thermal features. published research, as well as older data, such as the results of drilling that occurred in 1929, • Midway Geyser Basin – This is the site of 1930 and the 1960s. Where appropriate, we will Grand Prismatic Hot Spring, which is the weave in links among geological, biological and largest in the park, and among the most cultural (human history) factors as part of our colorful. We will travel along the boardwalk conversations. to see both Grand Prismatic and the crater left by Excelsior Geyser. Among the sites that we plan to see are:

Grand Prismatic and Excelsoir Hot Springs from above. PHOTO BY DUNCAN FOLEY • Upper Geyser Basin – This area is home to many of the Park’s most famous geysers. We will see Old Faithful, and discuss what is currently inferred about the subterranean plumbing of geysers, and look at potential interactions between thermal systems and human activities. We will select the route of our walks based on short- term forecasts for other major geysers, such as Grand, Riverside and Daisy. There will be options for short walks, as well as an option for a walk of several miles.

Two views of Porcelain Basin at Norris. On the top is a normal view. On the bottom is a Forward Looking Infrared (FLIR) image showing the same scene. The hot areas show up as paler areas in the image. PHOTOS BY DUNCAN FOLEY

34 GRC Bulletin l www.geothermal.org • Mud Volcano area – This is a large zone of vapor-dominated features, such as mud pots, fumaroles and vapor-driven churning pools. We will discuss the geologic history of this area, as well as caldera unrest, while we walk the boardwalks here.

• Mary Bay – Hydrothermal explosion craters are one of the manifestations of a highly active volcano. Mary Bay, located on the north shore of , is one of the largest such craters in the world. We will walk along its hot shoreline and discuss the origins of hydrothermal explosions and the risks such explosions currently present to visitors.

• West Thumb Geyser Basin – This area is home to Fishing Cone and other thermal features that poke through the lake’s surface. West Thumb will be our last look at geysers before we head south.

Beehive (foreground) and Old Faithful geysers erupting simultaneously. PHOTO BY DUNCAN FOLEY

Fishing Cone Geyser - Walter Trumbull of the 1870 Washburn-Langford- Doane Expedition described a unique event while a man was fishing adjacent to the cone: “…in swinging a trout ashore, it accidentally got off the hook and fell into the spring. For a moment it darted about with wonderful rapidity, as if seeking an outlet. Then it came to the top, dead, and literally boiled.” PHOTO BY IAN CRAWFORD

• On Saturday afternoon we will leave Riverside Geyser. PHOTO BY ROY MINK Yellowstone and drive to Jackson, , • Grand Canyon of Yellowstone – The Grand where we will stay Saturday night. Our drive Canyon provides a three-dimensional will take us past the Teton Range. We will crosscut through highly altered rocks, which stop at least once on our drive to stretch our host hydrothermal systems. We will look at legs and view the spectacular mountains. the intricate fracture networks that occur in the rocks as analogues for water circulation beneath geyser basins.

May/June 2017 35 Registration Sign-up on the GRC Annual Meeting webpage at https://geothermal.org/meet-new.html. There are only 24 places available so register as soon as you can. Included in the cost of the fieldtrip is transport in a luxury minibus, double occupancy accommodation at two hotels, daily breakfast and lunch and one group dinner at the Old Faithful Inn.

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A GRC Fieldtrip in Grand Teton National Park, 2015. PHOTO BY IAN CRAWFORD Trip Leaders GRC Fieldtrips offer the opportunity to observe Sunday, October 1 geothermal features in beautiful surroundings and For those who are interested, we will to offer learn about the science of geothermal energy from a sunrise trip to photograph the Tetons. After world-renowned experts in the field. This trip will returning to town for breakfast and joining with be no exception. those who didn’t want to rise well before the sun, we will drive back to Salt Lake City. We will travel Roy Mink via a different route than we took northbound, Leland “Roy” Mink which will take us through the overthrust belt. This began his career as a route will give us the opportunity to discuss the hydrogeologist with the geology and thermal features of this fascinating, Idaho Bureau of Mines complex geological environment. and Geology. He was a geothermal energy project manager for the Department of Energy, spent eight years as a hydrology project engineer for Morrison-Knudsen Co in Boise, and for more than ten years directed the Idaho Water Resources Research Institute at the University of Idaho. Most recently, he was Program Director of the Geothermal Technologies Program for the Department of Energy in Washington DC. Currently, he is consulting in water and geothermal energy in both domestic and The Teton Range rises to more than 13,000 feet above sea level. PHOTO BY international projects and is a GRC Board Director. DUNCAN FOLEY Roy has taught summer courses at the Yellowstone Institute for 25 seasons. Over the years, he has led many field trips through the park and surrounding areas.

36 GRC Bulletin l www.geothermal.org Duncan Foley Duncan Foley has All attendees been leading field trips on the fieldtrip will and conducting research get a copy of the in Yellowstone Park for 40-page full-color more than forty years. He book "Yellowstone’s has taught the geology of Geysers and other Yellowstone to geothermal hydrothermal professionals, park guides, systems" by tour tourists, and the Park leader Duncan Foley. Service. He is currently conducting research on PHOTO BY MANUEL CANALES the near-surface geology ~~~~~~~ of Old Faithful Geyser and For the most up-to-date the nearby thermal deposits. information on this fieldtrip go to Duncan’s photographs of Yellowstone’s thermal the Fieldtrips webpage for the GRC features and descriptions of their geology are Annual Meeting at: https://goo.gl/ highlighted in his book, “Yellowstone’s Geysers CHspdO n and other hydrothermal systems”, which is in now in its third printing.

Registration Opens Late June

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