OUTCROP
Newsletter of the Rocky Mountain Association of Geologists
OUTCROP
Newsletter
of the Rocky Mountain Association of Geologists
730 17th Street, B1, Denver, CO 80202 • 720-672-9898
The Rocky Mountain Association of Geologists (RMAG) is a nonprofit organization whose purposes are to promote interest in geology and allied sciences and their practical application, to foster scientific research and to encourage fellowship and cooperation among its members. The Outcrop is a monthly publication of the RMAG.
2025 OFFICERS
PRESIDENT
AND BOARD OF DIRECTORS RMAG STAFF
Matthew Bauer matthew.w.bauer.pg@gmail.com
PRESIDENT-ELECT Sandra Labrum slabrum@slb.com
1st VICE PRESIDENT
Nate La Fontaine nlafontaine@sm-energy.com
1st VICE PRESIDENT-ELECT Rachael Czechowskyj sea2stars@gmail.com
2nd VICE PRESIDENT Ali Sloan ali@sloanmail.com
2nd VICE PRESIDENT-ELECT Lisa Wolff lwolff@bayless-cos.com
SECRETARY Drew Scherer latirongeo@gmail.com
TREASURER
Astrid Makowitz astridmakowitz@gmail.com
TREASURER-ELECT
Walter Nelson wnelson@integratedenergyresources.com
COUNSELOR
John Benton jbenton@haitechinc.com
ADVERTISING INFORMATION
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The Outcrop is a monthly publication of the Rocky Mountain Association of Geologists
DESIGN/LAYOUT: Nate Silva | n8silva.com
EXECUTIVE DIRECTOR
Bridget Crowther bcrowther@rmag.org
LEAD EDITOR
Danielle Robinson danielle.robinson@dvn.com
CONTRIBUTING EDITORS
Elijah Adeniyi eadeniyi@slb.com
Nate LaFontaine nlafontaine@sm-energy.com
RMAG CODE OF CONDUCT
RMAG promotes, provides, and expects professional behavior in every engagement that members and non-members have with the organization and each other. This includes respectful and inclusive interactions free of harassment, intimidation, and discrimination during both online and in-person events, as well as any content delivered by invited speakers and instructors. Oral, written or electronic communications that contain offensive comments or demeaning images related to race, color, religion, sex, national origin, age, disability, or appearance are not appropriate in any venue or media. RMAG reminds members of the diversity and mission statements found on our website. Please direct any questions to staff@rmag.org
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COMMUNITY CONTACTS IN 2024YOUR SUMMIT SPONSORSHIP DOLLARS SUPPORTED: 1,200 1,200 8,000 8,000 5,000 4,000 23 13 10
October 30, 2024
Geoscience Community:
We sincerely appreciate the support every Summit Sponsor and Event Sponsor provided over the past year. Your contributions are vital to the success of the Rocky Mountain Association of Geologists (RMAG).
In 2024, the RMAG was proud to host a dynamic lineup of events, including the CCS Workshop, which provided an in-depth look at advancements in carbon capture and storage. Members explored the beauty and geological wonders of the Colorado Rockies with ten diverse field trips and shared our passion for geoscience with students across the region through classroom visits and community festivals. Additionally, we fostered connections among members through monthly lunches, coffees, happy hours, and our annual Golf Tournament.
Looking ahead to 2025, we are excited about new opportunities for RMAG. Your sponsorship will help RMAG realize a robust calendar of continuing education opportunities, an exciting season of field trips, high-impact short courses, and a dynamic lineup of luncheon speakers. In April 2025, we look forward to the North American Helium & Hydrogen Conference, building on the success of our 2023 North American Helium Conference. Your sponsorship empowers RMAG members to impact the next generation at outreach events throughout the community and provides invaluable networking opportunities for the geoscience community. Furthermore, your financial support plays a crucial role in our publication efforts, which include the monthly Outcrop newsletter and the quarterly Mountain Geologist journal.
In recognition of your financial commitment to supporting geoscience in the region we recognize our sponsors through in-person signage, advertising on our website, publications, and social media promotions leading up to each event. With a LinkedIn group of almost 3,000 members, we ensure our sponsors are visible to the geoscience community for both virtual and in-person events.
Thank you to our current Summit Sponsors; we look forward to your continued support in 2025. For those considering sponsoring, we encourage you to explore the many benefits included at each sponsorship level and consider how you can promote geoscience in the Rockies. If an annual sponsorship doesn’t suit your company’s needs or if you wish to sponsor a specific event, please inquire about our single-event sponsorship opportunities. Feel free to reach out to our staff with any questions about sponsorship at bcrowther@rmag.org or by phone at 720- 672-9898 ext. 102.
On behalf of the RMAG staff, volunteers, and myself thank you all for your continued support, and we look forward to connecting with you in 2025.
Sincerely,
Matthew Bauer
Bridget Crowther 2025 RMAG President RMAG Executive Director
RMAG 2025 SUMMIT SPONSORSHIP
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RMAG MAY 2025 BOARD OF DIRECTORS MEETING
By Drew Scherer, Secretary flatirongeo@gmail.com
With summer just around the corner, the RMAG Board of Directors gathered via Zoom on May 21st to keep the gears turning across all fronts. With solid attendance and spirited committee updates, the meeting covered everything from investment planning to family hikes.
It was a strong month financially, thanks to successful events like the helium/hydrogen conference and the sold-out Grand Canyon raft trip. RMAG netted over $72K in total revenue, including gains and losses from our investment accounts. The Finance Committee also announced that they’ll be introducing a new investment strategy proposal at next month’s meeting, aimed at ensuring long-term financial resilience.
The Continuing Education Committee is
brimming with ideas. Luncheons are booked through November, and planning is underway for a 2026 basin-focused conference. Career fairs, Python courses, and talks on AI and geothermal are also in the mix, ensuring our programming continues to evolve with the industry.
Summer fun is heating up on the Membership Committee. Upcoming events include a kid-friendly hiking passport series, a July volleyball in the park day, and the annual golf fundraiser in August. The committee is actively seeking new members to help plan these social events, if you’re interested in being part of the fun behind the scenes, we’d love to hear from you!
The Publications team remains on track with a packed publishing schedule. Outcrop editions are lined up through August, and the spring issue of The Mountain Geologist is in layout, featuring topics ranging from dinosaur fossils to detrital zircon dating.
The Geoscience Outreach Committee is fresh off a successful Cinco de Mayo event and gearing up for Juneteenth and Pride in June. Plans are also in motion for summer science field trips for kids and fall events with local museums and schools.
Finally, On The Rocks is riding the momentum of two soldout spring trips and has a full field season ahead. They’re also exploring the creation of an annual Denise Stone Memorial Trip, honoring her legacy and generous donation to RMAG.
From investment strategies to field trips, career fairs to community outreach, RMAG is charging into summer with purpose and enthusiasm. We hope to see you out there!
GLENWOOD SPRINGS CAVE AND CARBONATES 10-11 MAY
DOTSERO VOLCANO RESCHUDLED DATE TBD
SALIDA TO CANON CITY TRANSECT 23-24 AUGUST
6 SEPTEMBER LYONS-INGLESIDE/RED MOUNTAIN OPEN SPACE 17 MAY
OURAY - SAN JUAN MOUNTAINS 19-21 SEPTEMBER
PICKETWIRE DINOSAUR TRACKWAY 4-5 OCTOBER
PUEBLO LOWER CRETACEOUS 18 OCTOBER
Dates subject to change. View website for additional info.
PRESIDENT’S LETTER
By Matthew Bauer
Fellow Members,
Summer is upon us, and with it comes the perfect excuse to step outside and reconnect with the land beneath our feet. I just returned from a camping trip at Mueller State Park, nestled on the west side of the Pikes Peak batholith. The weekend was filled with fresh mountain air, bright green rustling aspens, campfires, and the joyful noise of kids exploring the woods.
What struck me most wasn’t just the beauty of the park, but the curiosity it sparked. Children wandered the woods collecting bits of white quartz, their pockets full of “gems,” and their minds full of questions. “Why are these here?” “Are they treasure?” “Why are they in lines?” These simple questions open doors to deeper conversations about earth science, geology, and the ancient forces that shaped
Colorado’s many geologic landscapes.
We’re lucky to live in a region so geologically diverse — from granite intrusions weathering into rolling mountains, fossil beds, hogbacks, canyons, volcanic terrains, to glacial valleys. These outdoor classrooms offer something screens never can: direct, hands-on awe. Whether you’re an expert or a novice, there’s nothing quite like watching a child discover the world beneath their boots, on their terms, at their own pace.
Camping, hiking, and simply turning over a rock can be the start of a lifelong interest in science. I encourage anyone with kids — or just a curious mind — to head outside this season. Go find a rock, ask questions, and see the path it leads down.
Stay curious & Be Good to People,
-Matthew W. Bauer, PG
Saturday June 21, 2025 Saturday June 21, 2025
South Valley Park - North Trail Head
South Valley Park - North Trail Head
More and RSVP @ rmag.org /familyhike
CORPS OF DISCOVERY IN MONTANA THE GEOLOGICAL STORY OF THE
BY STEVEN L. QUANE Montana Bureau of Mines and Geology
INTRODUCTION
Tense from incessant rattlesnake warning signs, I ease the loaded canoe from the bank into the murky, reed-laden water of the longest river in the United States with simultaneous trepidation and anticipation. Venturing into personally novel territory guided by the lasting missives of the Corps of Discovery, I navigate the lazy current, a few paddle strokes relax my rigid frame. My mission is miniscule relative to what Lewis & Clark and the Corps of Discovery achieved, but the planning and effort have nonetheless been significant. The fundraising, gear-sourcing, route-mapping, packing and driving done, excitement overtakes trepidation. As a neophyte waterman, the rocking imbalance with each paddle stroke preoccupying my mind slowly gives way to the solace of processing scientific observations. The flow of the current and the nature of the stratigraphy on the immediate banks and distant hills revive and inspire the geologist set to explore the White Cliffs section of the Upper Missouri River
Breaks National Monument (Figure 1). My modest goals include exploring the “scenes of visionary enchantment” noted by Meriwether Lewis in 1805, including a “white free-stone...worn into a thousand grotesque figures” as well as “walls of tolerable workmanship”. I will be overnighting in the same camps as the Corps of Discovery on their up-river journey. In addition, on my return from the river, I extend my quest to explore “the largest fountain or spring I ever beheld” with hopes of understanding and explaining the observations of Meriwether Lewis in the context of today’s geologic paradigm. Indeed, the Corps of Discovery were not the first peoples to interact with and attempt to understand these landscapes. However, their journals are the oldest written observational record of rock types and landforms to which we have access. In 1805, the science of Geology was in its infancy; therefore, the Corps of Discovery had little to no training in the subject. That being said, while some of their interpretations do not stand the test of time, their core observations hold great value.
GEOLOGIC CONTEXT
Ferried along by the current, I try to imagine the immense effort and scenes of unspoiled countryside as Lewis and Clark and the Corps of Discovery trudged upriver through the White Cliffs section of the Missouri River in May 1805 and Meriwether Lewis and crew returned downriver in July 1806 (Figures 2a & b). After a few minutes on the river, the pace of my once fledgling, now burgeoning J-stroke quickens in response to a glimpse of river-bounding cliffs in the distance. Are these the famed White Cliffs of the Virgelle Sandstone Member of the Eagle Formation? My pretrip planning included pouring over Montana Bureau of Mines and Geology (MBMG) maps to determine what geologic units I would encounter (Figures 3a & b). If I am correct, the mud drying in the roasting sun on my rapidly pinkening, sandal-clad feet must be derived from shales from either the Telegraph Creek or Claggett Formations. As I move downriver, I expect to find sedimentary facies associated with the shifting shoreline of a shallow Cretaceous seaway intruded
by ~50-million-year-old igneous rocks of the Central Montana Alkalic Province, associated with the Laramide Orogeny. With growing confidence in both the surrounding stratigraphy (Figure 4) and my borrowed canoe, I maneuver toward the cliffs, truly engrossed in the journey ahead.
THE WHITE CLIFFS – A MOST ROMANTIC APPEARANCE
Reaching out to feel some of the billions and billions of grains of sand that make up the Virgelle Sandstone cliff from my position on the water, the geologist in me is trying to reconcile modern day observations and interpretations with particular passages written by Meriwether Lewis in the journals of the Corps of Discovery on May 31st, 1805…
“The hills and river Cliffs which we passed today exhibit a most romantic appearance. The bluffs of the river rise to the height of from 2 to 300 feet and in most places nearly perpendicular; they are formed of remarkable white sandstone which is sufficiently soft to give way
FIGURE 1: I observe the famed White Cliffs as I traverse the current of the Missouri River.
FIGURE 2A: (above) Map of the route and campsites of Lewis and Clark in Montana. Modified from Bergantino and Sundau, 2004; MBMG Publication SP 116. Black box denotes area shown in Figure 2b. Blue dots represent camps in 1805, red in 1806. L and C stand for Lewis and Clark, respectively.
FIGURE 2B: (below) Close-up of the route and campsites of Lewis and Clark in Montana focusing on the White Cliffs and Great Falls area covered during my journey. Modified from MBMG Special Publication 116. Colors and labels as in Figure 2a.
FIGURE 3A: (above) Geologic map of Montana simplified from Vuke, S.M., Porter, K.W., Lonn, J.D., and Lopez, D.A. 2007, MBMG Geologic Map 62A. Black box denotes area shown in Figure 3b.
FIGURE 3B: (below) Detailed geologic map focusing on the White Cliffs and Great Falls area covered during my journey. Map simplified from Vuke, S.M., Porter, K.W., Lonn, J.D., and Lopez, D.A., 2009 Geologic Map of Montana Field Notebook, MBMG Geologic Map 62E. Relevant map units described in Figure 4.
Coffee Hour
June 26, 2025 10am
Denver Earth Resources Library 730 17 St. B1 th Denver, CO
Join RMAG for a special coffee hour at the Denver Earth Resources Library. The Library is looking to rehome duplicates of its extensive collection of RMAG publications (list coming soon), and others. Are you looking to fill out your own personal collection or your offices? Stop by and see what we have and consider a donation to the library to support their continued curation of geoscience in the Rocky Mountain Region.
Don't need more books for your own library, come by and join us of a coffee and pastries any way and connect with local geoscientists.
RSVP AT RMAG.ORG/COFFEE
readily to the impression of water; two or three thin horizontal strata of white free-stone, on which the rains or water make no impression, lie imbedded in these cliffs of soft stone near the upper part of them…”
Indeed, the Virgelle Sandstone is soft. As I dunk my hand in the cool water to rinse off sand grains from touching the wall, cliff swallows peer down at me from their nests of mud likely sourced from the nearby Marias Formation. Moving downstream, the river at a leisurely summer pace, I seek fleeting shade beneath cliffs that consistently tower vertically from the water (Figure 5a). I drag my canoe onto the sandy bank and venture inland, and see more evidence of the Virgelle Sandstone as “sufficiently soft to give way readily to the impression of water”. The bluffs are pock-marked by interaction with wind and water (Figure 5b). Also present throughout the unit are layers stained brown from iron concretions that constitute more resistant horizontal strata.
“The water in the course of time in descending from those hills and plains on either side of the river has trickled down the soft sand cliffs and worn it into a thousand grotesque figures, which with the help of a little imagination and an oblique view at a distance, are made to represent elegant ranges of lofty freestone buildings, having their parapets well stocked with statuary…”
Hiking the sandy trail up to the top of the Virgelle Sandstone, I weave between individual rock spires that take on curious shapes, commonly exhibiting a human or ghostly appearance (Figure 5c). Of course, these “grotesque figures” are what we call hoodoos, spires of less resistant rock protected by an overlying cap rock. Once perched on top of the unit, I look down and see a geological reason explaining the nature of the sheer cliffs and hoodoos. The Virgelle Sandstone has at least two main joint orientations that intersect at roughly 90 degrees (Figure 5d). Erosion along the main joint surface cleaves the sandstone into cliffs parallel to this part of river, while the intersection of the joints creates pillars eventually sculpted into hoodoos. As I move downriver, I continue to observe more of Lewis’ perceptive descriptions through a modern lens…
“columns of various sculpture both grooved and plain, are also seen supporting long galleries in front of those buildings; in other places on a much nearer approach and with the help of less imagination we see the remains or ruins of elegant buildings; some columns
FIGURE 4: Idealized stratigraphy of the White Cliffs and Great Falls area. Information sourced from various MBMG Publications.
FIGURE 5A: The White Cliffs of the Upper Missouri River Breaks reflect in the morning light near Eagle Creek Camp.
FIGURE 5B: I stand atop ancient sand dunes preserved in the Virgelle Sandstone.
FIGURE 5C: A curious hoodoo in the Virgelle Sandstone perched above the Missouri River.
FIGURE 5D: A view from above the Virgelle Sandstone showing weathering influenced by the main jointing surfaces.
how it was formed through continual weathering along the vertical joints
FIGURE 5E: I ascend the trail towards the hoodoos and pillars to the Hole in the Wall formation (far left on ridge).
FIGURE 5F: Looking through the Hole in the Wall formation, one can see
in the Virgelle Sandstone.
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standing and almost entire with their pedestals and capitals; others retaining their pedestals but deprived by time or accident of their capitals, some lying prostrate and broken others in the form of vast pyramids of conic structure bearing a series of other pyramids on their tops becoming less as they ascend and finally terminating in a sharp point…”
I pull my canoe onto a silty bank comprised of shales of the Marias Formation, and stare expectantly up at a feature called Hole in the Wall. Seeking a cool breeze to escape the stifling stillness at river level, I ascend through beautiful pillars whose shapes are aptly described by Lewis and mount the ridge (Figure 5e). As I traverse the spine directly above the Hole in the Wall, clues to its formation become evident underfoot. One can see that a fracture through the Virgelle Sandstone has expanded to create the window-like void (Figure 5f). This particular feature is not mentioned anywhere in the Corps of Discovery journals, so perhaps it has formed in the intervening 220 years? Likely such a feature would not have gone unnoticed by the Corps, given their penchant for keen observations including:
“the thin strata of hard freestone intermixed with the soft sandstone seems to have aided the water in forming this curious scenery.”
IGNEOUS INTRUSIONS - SCENES OF VISIONARY ENCHANTMENT
Trained as a volcanologist, I admit a volumetrically less significant rock type continually pulled my attention and focus away from the dominant sedimentary rock stratigraphy. Intrusions of shonkinite, a rare volcanic rock, also drew the eye of Meriwether Lewis:
“As we passed on it seemed as if those scenes of visionary enchantment would never have and end; for here it is too that nature presents to the view of the traveler vast ranges of walls of tolerable workmanship, so perfect indeed are those walls that I should have thought that nature had attempted here to rival the human art of masonry had I not recollected that she had first began her work. These walls rise to the height in many places of 100 feet, are perpendicular, with two regular faces and are from one to 12 feet thick, each wall retains the same thickness at top which it possesses at bottom. The stone of which these walls are formed is black, dense and durable, and appears to be composed of a large portion of
earth intermixed or cemented with a small quantity of sand and a considerable portion of talk or quarts.”
Trapsing through knee-high vegetation laden with burrs, I ignored the discomfort on my bare legs and the lingering fear of snakes to investigate a beautiful igneous dike cutting through the Virgelle sandstone (Figure 6a). It turns out, the “black, dense and durable” walls are comprised of a gray porphyritic igneous unit with a dark exterior coating. And rather than being “earth intermixed or cemented with a small quantity of sand and a considerable portion of talk or quarts”, this particular outcrop comprises a fine-grained potassium feldspar-bearing crystalline groundmass with small phenocrysts of olivine, pyroxene, hornblende and biotite peppered throughout. Quickly, I excuse Lewis for his misidentification as this particular composition I had not seen before in 25 years researching and teaching igneous rocks in the field and laboratory (Figure 6b). Excitedly, I tag this unit as the rare shonkinite from the Central Montana Alkalic Province. Surrounding the river and in the hills beyond, I begin to recognize more erosional remnants of this low-silica, high-potassium volcanic rock. The remnants are dikes and plugs from feeder systems of what must have been expansive lava fields that were subsequently eroded away over the past ~50 million years.
The following morning, I rise stiffly my tent at Eagle Creek camp to view the river cliffs in the morning light. Undoubtedly, the Corps of Discovery did the same on May 31, 1805. I was immediately inspired to continue my journey after seeing the “tolerable workmanship… that nature had attempted here to rival the human art of masonry”. Lewis’ words must be a reflection of the presence of columnar jointing in La Barge Rock, a large shonkinite massif immediately across the river (Figure 6c). Columnar jointing is a fracture pattern that develops perpendicular to a cooling surface in igneous rocks. The material cools and contracts, commonly in a hexagonal pattern. I harken back to researching these features in the mountains of British Columbia and on black sand beaches of Iceland and beam with excitement to see them in central Montana. Buoyed by this discovery, I splash into the muddy current to see what more this journey has in store…
“These walls pass the river in several places, rising from the water’s edge much above the sandstone bluffs, which they seem to penetrate; thence continuing
6B: Close-up of the shonkonite dike from Figure 6a showing a fine grained matrix with phenocrysts of olivine, pyroxene, hornblende and biotite. My pencil points towards my personal favorite, olivine.
FIGURE 6A: I walk through the brush towards a shonkinite dike cross-cutting the Virgelle Sandstone.
FIGURE
FIGURE 6C: A near full moon above La Barge Rock shonkinite. I have traced the columnar jointing visible in the morning sun and sketched in a likely cooling surface.
FIGURE 6D: A shonkinite dike shown on both sides of the river near Eagle Creek Camp.
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FIGURE 6E: A shonkinite dike disappearing into the hillside far above river level.
FIGURE 6F: A shonkinite dike providing support for the Virgelle Sandstone to create the ridge of the Hole in the Wall formation.
FIELD TRIPS
From Canada to trinidad, these trips will rock your brain!
April 25 - Day Trip Through Colorado's Collections. A day behind the scenes at Dinosaur Ridge, Morrison Natural History Museum, and the Denver Museum of Nature and Science.
May 17 - Day Trip to Red Rock Canyon. A geology-focused hike through Red Rock Canyon in Colorado Springs. Trip will be led by Dr. Louis Taylor.
June 6-8 - Green River Fish Dig. We partner with Fossil Lake Safari in Kemmerer for a full day dig, and exploration & guest speaker at Fossil Butte National Monument.
September 9-14 - Alberta Badlands. Dr. Robert Raynolds will lead this exploration of Alberta's dinosaur badlands! Only a couple of spots remain, sign up TODAY!
October 11-12 - A Trip to the End of an Era. We'll travel south to the Paint Mines and Trinidad, Colorado to see the K/Pg boundary, the dinosaur extinction line. Led by Dr. Louis Taylor. register today! member discounts available!
their course on a straight line on either side of the river through the gradually ascending plains, over which they tower to the height of from ten to seventy feet until they reach the hills, which they finally enter and conceal themselves. these walls sometimes run parallel to each other, with several ranges near each other, and at other times intersecting each other at right angles, having the appearance of the walls of ancient houses or gardens.”
Indeed, the dike and plugs are visible crossing the river as I continue downstream (Figure 6d) and from viewpoints high off the river, you can see them disappearing into the distant hills (Figure 6e). In places, the dikes are continuous for several miles cutting through the Cretaceous sediments. On my journey up to Hole in the Wall, I notice that the dike actually supports the sandstone ridge (Figure 6f), preserving this erosional landmark, for the time being.
Bald eagles monitor my progress, binoculars often pressed to my face, as I allow the current to slowly drift me downstream and down section, going further into the geologic past. The river-bounding cliffs give
way to gentle shale slopes as the river’s course widens and the current slows. The ghostly faces of hoodoos no longer peer at me from the banks as I make my final paddle strokes to pull ashore at Judith landing. After 47 miles on the river, despite my sore back and sunburned knees, I crave more of what Lewis and Clark and the Corps of Discovery observed and described.
GIANT SPRINGS – THIS FOUNTAIN, THE LARGEST I EVER BEHELD
The chore of loading the canoe and gear and shuttling the trucks finished, I check the map to plot my journey home. Mildly annoyed by the lack of good phone service to use my digital devices, I humorously reflect on the relative ease and comfort of my journey and dare not imagine the hardships of the Corps. I decide to take advantage of my modern conveniences and make one more stop along their journey, this one a Montana State Park in suburban Great Falls. What is now called Giant Springs was observed by Lewis on June 29th, 1805:
“I think this fountain the largest I ever beheld, and the handsome cascade which it affords over some steep and irregular rocks in it’s passage to the river adds not a little to it’s beauty. It is about 25 yds. from the river, situated in a pretty little level plain, and has a sudden descent of about 6 feet in one part of it’s course. The water of this fountain is extremely transparent and cold; nor is it impregnated with lime or any other extraneous matter which I can discover, but is very pure and pleasant. It’s waters mark their passage as Capt. Clark observes for a considerable distance down the Missouri notwithstanding it›s rapidity and force.… the water of the fountain boils up with such force near it’s center that it’s surface in that part seems even higher than the surrounding earth which is a firm handsome turf of fine green grass.”
I navigate the park’s paved walkway in the summer heat under smoke-filled skies and savor intermittent cool breezes wafting from the spring which keeps a constant temperature of 54 degrees Fahrenheit. Due to the dams constructed on the Missouri
FIGURE 7A: Google Earth image showing the location of Giant Springs as well as several springs in the middle of the Missouri River. The dark blue spring water is seen mingling with the river water as it flows downstream. The water from Giant Springs noticeably hugs the near bank for an appreciable distance (estimated at ½ mile by William Clark).
FIGURE 7B: View as I look over Giant Springs towards the nearby Missouri River. The upwelling springs feed the short but mighty Roe River.
FIGURE 7C: Water from Giant Springs pours over the Kootenai Sandstone on its way to the Missouri River. Fractures created by perpendicular joint surfaces are visible in the Kootenai Sandstone. Flow along these surfaces allow the groundwater to reach the surface.
7D: An underwater scene in Giant Springs taken near an upwelling spring. One can see an exsolved gas bubble moving towards the disturbed surface of the water from a point source below.
FIGURE
8: Simplified cross section detailing the flow of groundwater originating as precipitation in the Little Belt Mountains through the Madison Limestone to Giant Springs.
River in the late 1800’s and early 1900’s, the spring is now very close to the banks of river (Figure 7a). From above, you can see water springing up underneath the middle of the river and trace the path of the deep blue spring water as it flows “down the Missouri notwithstanding it›s rapidity and force”. I stand hypnotized by the roiling of the water in the springs which bring 156 million gallons a day of freshwater to the surface (Figure 7b). I later learn from my colleague, MBMG Hydrogeologist and Research Division Chief John LaFave, that these waters originate as precipitation about 25 miles south in the Little Belt Mountains and travel through the Madison Formation as groundwater (Figure 8). Hydraulic head forces water to the surface through systematic cracks from jointing in the sandstone of the Kootenai Formation (Figure 7c). As the water reaches the surface, you can see gases exsolve, likely CO2 that was sourced from dissolution of the Madison Limestone (Figure 7d). Unpublished analyses of chlorofluorocarbons in the water indicate a recharge date of 24 years, meaning it travels at about 1 mile per year in this part of the aquifer to reach Giant Springs. Standing at the confluence of America’s shortest river, the Roe, and its longest, the Missouri (Figure 7b), I reflect on the rapid pace of human development of the Rocky Mountain west and wonder what it must have been like to come upon a scene like this unaware of its existence:
“I continued my route to the fountain which I found much as Capt. C; had described & think it may well be retained on the list of prodigies of this neighbourhood towards which, nature seems to have dealt with a liberal hand, for I have scarcely experienced a day since my first arrival in this quarter without experiencing some novel occurrence among the party or witnessing the appearance of some uncommon object.”
What a journey.
NOTES
The Meriwether Lewis quotes used here were sourced from The Journals of the Lewis and Clark Expedition Online from the University of Nebraska. They were lightly edited for modern reading. This work stems from previous efforts and publications of MBMG scientists Bob Bergantino, Kenneth Sundau and Ginette Abdo. Thanks go to MBMG Geologist Yan Gavillot for loaning his canoe to an amateur canoeist. An excellent reference for a journey downriver include Magnificent Journey: A Geologic River Trip with Lewis and Clark trough the Upper Missouri River Breaks National Monument by Schumacher and Woodward, 2004. Funding was provided by MBMG and the Foundation for Montana History. All photos were taken by Steve Quane. A video production of this journey can be viewed on the MBMG YouTube channel.
FIGURE
The GCSSEPM Foundation 41st Annual Perkins-Rosen Research Conference
17- 19 November 2025 Houston, TX
Cycles and Sequences, So What? A 21st century perspective in memory of Peter Vail, Bob Weimer, and Larry Sloss Announcement and Call for Papers
With the recent passing of Pete Vail and Bob Weimer and the approaching 50th anniversary of the publication of AAPG Memoir 26, not to mention the recent retirements of the 1st generation that grew up with Memoir 26 and the rise of new generations of practitioners and innovative techniques, it is a propitious time to take stock of sequence stratigraphy in particular and applied stratigraphic analysis in general: where it came from, where’s it going, and what’s it good for…and to pass along hard-won practical lessons.
This year’s conference features a hybrid program of short talks by practitioners who worked with Vail, Weimer, and Sloss, as well as those who have applied and expanded their concepts, hands-on exercises, discussions, case-study talks, and panel discussions that illustrate each of four focus areas:
• Historical Perspectives on the development of present-day integrated stratigraphic analysis since Sloss (e.g., incorporation of high-resolution age control and seismic, expansion to non-marine systems, etc.).
• Regional- to basin-scale concepts and applications (e.g., cycle chart uses and abuses, tectonic influences, systematic changes in reservoir-target age across a basin, etc.).
• Play- to field-scale concepts and applications (e.g., incised valleys, resource plays, sub -unconformity plays).
• Practical applications and tools for energy and other resources (groundwater, GCS/CCUS, H2 storage) and planets.
This program will offer opportunities to examine classic data sets in a series of collaborative exercises, affording a shared experience to focus discussion of foundational concepts…and assumptions…considering more than 50 years of application, experience, and innovation. We welcome industry and academic practitioners who have tested, applied, improved, and expanded these concepts, students and practitioners who would benefit from understanding their development and application, and researchers looking for new opportunities to advance these concepts.
We invite a diverse set of papers illuminating the history of integrated stratigraphic analysis and the near-term and long-range future, especially those that explore the practical application of such analyses to hydrocarbon and critical mineral exploration, groundwater, geothermal, and emerging resource exploitation, and the interpretation of the geological history of Earth and Mars. Student posters and presentations are encouraged.
Organizing Committee - Conveners
Kevin Bohacs: bohacsk@gmail.com; KMBohacs GEOconsulting LLC, Houston, Texas
Art Donovan: art.donovan@tamu.edu; Professor & Director UROC, Texas A&M University
Jack Neal: jeneal2022@gmail.com; Consultant, Houston, Texas
Keith Shanley: keith_shanley@oxy.com; Geological Consultant, Oxy Petroleum, Denver, Colorado
Steve Sonnenberg: ssonnenb@mines.edu; Colorado School of Mines, Golden, Colorado
Important Dates and Deadlines Perkins-Rosen
June 1 – 15, 2025
June 30, 2025
August 4, 2025
October 3, 2025
Expression of interest: Provide title of presentation and brief abstract (~250 words, to fit on one page)
Preliminary Program Announced
Abstracts, Extended Abstracts, and Full papers due See below for guidelines on format and length
Final revised manuscript and illustrations due
November 17-19, 2025 Conference in Houston
Abstract submission opening and Venue details coming soon to: https://sepm.org
General information for Abstracts, Extended Abstracts, and Full papers
o Abstracts should fit on one page (body text = Arial 11pt, double-spaced, single column for all submissions).
o Extended Abstracts can be 2 to 4 pages (excluding references).
o Full Papers can be up to twelve (12) pages (excluding acknowledgements, illustrations and references).
o Microsoft Word format for draft and final submissions; documents will be converted to .pdf for publication
o Illustrations: Resolution: 300 to 600 dpi; Landscape or portrait orientation; up to 11 x 17 in. (or A3)
o Prefer figures at end of draft submissions, clearly identified as Figure ##
o References: SEPM Special Publication format preferred, but not necessary; references will be converted to SEPM format for publication. Use Arial 10 pt normal/roman font.
Guidelines for Extended Abstracts and Full Papers
- Title
- Author information – First name, middle initial, last name; Affiliation – do NOT include city/state with affiliation
- Summary
- Introduction (please indent all sub-headings)
o Statement of Problem
o Background information and previous work
- Method(s)
- Data and Results
- Discussion (please do not add any new data or information in this section!)
- Conclusions (consider summarizing as bullet points)
- Acknowledgements
- References
The GCSSEPM Foundation supports and follows the SEPM Code of Conduct
For more information, or to sponsor the Conference, contact John R. Suter, Executive Director, GCSSEPM Foundation at gcssepm1@gmail.com.
Speaker: William R. Drake
Date: June 4, 2025 | 12:00 pm - 1:00 pm
A Mass-Balance Organic Geochemistry Approach To Characterizing Hybrid Unconventional Plays
Examples from the Montney and Green River Formations
Presenter: William R. Drake, Kimmeridge Energy
Unconventional oil and gas plays range from true source-rock mudstones with little to no reservoir lithofacies to tight conventional reservoirs with little to no source rock potential. Most unconventional systems fall somewhere along this spectrum and can be considered hybrid plays. Quantifying the degree of self-sourcing and/or hydrocarbon migration are critical for spatially characterizing the variability of hybrid systems. Several mass-balance organic geochemistry techniques are employed here to quantify
hydrocarbon generation for comparison to resource in place and to produced oils. Two disparate formations and basins are used as examples: the Triassic Montney Formation (marine) of the Western Canadian Sedimentary Basin and the Eocene Green River Formation (lacustrine) of the Uinta Basin. These case studies highlight the importance of correctly characterizing unconventional systems and suggest implications ranging from identifying migration pathways to horizontal well-placement strategy.
WILLIAM R. DRAKE is senior geologist with Kimmeridge Energy, focusing primarily on asset-scale to basin-scale characterization of stratigraphy, source rocks, and overall petroleum systems in most of the basins from Texas to western Canada. He holds a B.S. in geological science from the University of California, Santa Barbara and an M.S. in Geology from the University of Northern Arizona, where he researched the extensional tectonics and stratigraphy of Baja California Sur and the southern Gulf of California. Before Kimmeridge, Bill worked for Pioneer Natural Resources, QEP Resources, and Jonah Energy. Bill also served RMAG for five years as Executive Editor for the Mountain Geologist.
JUNE 3, 2025
IN THE PIPELINE
WOGA Swing into Confidence: Golf Clinic.
Broken Tee Golf Course., Englewood, CO.4:30-6:30 PM.
JUNE 4, 2025
RMAG Lunch. Speaker: William Drake. “A Mass-Balance Organic Geochemistry Approach to Characterizing Hybrid Unconventional Plays: Examples from the Montney and Green River Formations.” 730 17th Street, B1, Denver.
JUNE 6, 2025
COGA Golf Tournament. The Ridge at Castle Pines. 8:00 AM.
JUNE 15, 2025
RMAG and Dinosaur Ridge Booth. Music Festival at Five Points., Denver, CO.
JUNE 17, 2025
DPC Breakfast Speaker Series. Speaker: John Harpole. “Natural Gas In and Out of the Rockies.”
JUNE 19, 2025
WOGA Lean- In. Speaker: Kelly Saucedo. “From Surviving to Thriving: Crafting Your Career Path.” CANUSA, 600 17th Street, #1400n, Denver. 11:00 AM-12:30 PM.
JUNE 21, 2025
RMAG Family Hike Series. South Valley Park-North Trail Head, 90 S Valley Rd, Littleton, CO.
JUNE 24, 2025
RMAG Happy Hour. Littleton Brewing Co., 1201 Littleton Blvd., Littleton, CO.
JUNE 26, 2025
RMAG Coffee Hour. 730 17th Street, B1, Denver.
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By Ronald L. Parker Senior Geologist, Borehole
Image Specialists, Centennial, CO 80111 ron@bhigeo.com
Prismatic translucent nahcolite from Anvil Point, Rifle, Garfield County, Colorado. Used with permission from John Betts Fine Minerals
Nahcolite, NaHCO3, is a rare, naturally-occurring mineral form of sodium bicarbonate, most commonly known to humans as ‘baking soda’. Nahcolite is an evaporite mineral formed in unusual saline lakes in association with the more common evaporites halite, trona, and dawsonite. In these settings, nahcolite is often found as an efflorescence around saline lake margins and as concretions and bedded layers in oil shales. Less abundantly, nahcolite is formed as a precipitate from hot springs and has been reported, in one instance, to be an inclusion in lower mantle diamonds. Nahcolite is exploited using solution mining techniques and is the major source of baking soda. Sodium bicarbonate has many applications beyond the kitchen, acting as an important feedstock for thousands of products. In addition to use as a chemical agent, nahcolite plays a significant role in helping geologists decipher geological process, both at the surface and in the mantle.
The name Nahcolite is clearly a reference to its
Powdered baking soda used in the kitchen experiment. In this pulverized material, there is no hint of the acicular monoclinic crystals that will develop from nucleating my supersaturated sodium bicarbonate solution. Photo by Ronald L. Parker
chemical formula. (Na+ = sodium, HCO3- = bicarbonate ion). NaHCO-lite! The type locality of nahcolite is from Mount Vesuvius, Naples, Campania, Italy. This mineral has also been called “thermokalite” (Bannister, 1929).
Nahcolite usually occurs as a colorless, white, gray, or brown clotted mass. It is colorless in transmitted light. Nahcolite is a soft substance (H=2.5), with a density of 2.2 to 2.35 g/cc. Nahcolite is monoclinic (2/m), with a prismatic habit. It has one perfect cleavage {101} and one good cleavage {111} and displays a vitreous to resinous luster. Nahcolite is fluorescent under both longwave UV (cream-white) and short-wave UV (bluewhite to cream yellow). One of nahcolite’s most endearing properties - one that is important in its thousands of uses for humanity – is that it is highly soluble in water.
Euhedral crystals of nahcolite are almost unknown. This makes sense given its rarity and the ease with which the hydrosphere erases its
Setup of my nahcolite crystal growing experiment in my kitchen. The pyrex bowl was filled with 167 g of Arm and Hammer Baking Soda dissolved in 500 mL of ~50°C hot water. I suspended a damp string from a chopstick coated in baking soda “seed crystals.” The bowl was placed in front of a small desk fan overnight. Crystal nucleation on the sides of the bowl and the string began almost immediately. Crystals occur as the mass adhering to the suspended string, as a thick layer on the bottom and as a bathtub ring of nucleated crystals around the edges. Photo by Ronald L. Parker
Close-up of the “tooth stub” crystal masses of NaHCO3 nucleated to the sidewalls of my pyrex bowl. “Look Ma, no cavities!” (Actually, there are many cavities). Photo by Ronald L. Parker.
crystals. Certainly, this renders nahcolite unfit as a collector’s mineral. This also means that it was difficult for me to find pictures of nahcolite to include in this article. I decided that I would try to make my own nahcolite crystals to see if any were worthy of photographing. I claim mixed results, but am mostly pleased. (I include more about this as an Appendix at the end of this article).
Nahcolite forms in several geologic settings –all unusual – including evaporative lakes, hot springs and from carbonatitic material from the mid- to deep-mantle. The most significant nahcolite occurrences are preserved in the evaporites, often associated with rich organic matter, from internally-drained, fossil, alkaline lakes. The rock star of this association is from the Parachute Creek Member of the Eocene Green River Formation in the Piceance Creek Basin of NW Colorado. In fact, this nahcolite occurrence is the largest presently known.
Let’s look at this amazing locality. The Piceance Basin nahcolite “occurs as disseminated aggregates, nodules, bedded units of disseminated brown crystals and white crystalline beds associated with dawsonite (NaAl(OH)2CO3) and halite (NaCl) (USGS, 2009). Brownfield et. al. (2010), describe the massive effort by the USGS to assess the nahcolite resource in this system. Nahcolite-bearing oil shale underlies a 266 mi2 area of Rio Blanco County, Colorado, ranging from ~100 ft. to more than 1,100’ thick in the nahcolite-halite depocenter. A 580’ zone of highly dissolved and “pseudo-karstified” rocks occur above the nahcolite bearing zones. These are interpreted to be intervals characterized by solution removal of nahcolite and halite. Fifty-eight coreholes were advanced into the Parachute Creek member, most in the thicker parts of the deposit. The details of the assessment analyses are too much to describe here, but the bottom line is that this resource is huge. Brownfield et. al. (2010), estimated that the 169,994 acres of the study area in Rio Blanco County, Colorado were endowed with 43.3 billion short tons of in place nahcolite.
Modern analogs to these enormous Eocene lakes are found in the East African Rift Valley, especially Lake Magadi and Nasikie Engida in Kenya.
These lakes are internally-drained and experience extreme geochemical conditions along with elevated rates of evaporation. Nahcolite occurs around the lake perimeters as efflorescences. Solution chemistry constraints for precipitation of nahcolite (and natrite and trona) are so severe that these natrocarbonates are not found in more “normal” lake systems. In fact, nahcolite requires elevated CO2 activity uncommon in most fresh-water or hypersaline lake systems today.
Nahcolite is an important mineral proxy for estimating the concentration of CO2 from the geologic past. Equilibrium experiments by Eugster (1966) established the stability fields in the system Na2HCO3-NaHCO3-CO2-H2O for Nahcolite + solution, Trona + solution and Natron + solution. The stability fields show that Natron is favored at lower pCO2 and lower T, Trona is favored at lower to midrange pCO2 and higher T and Nahcolite is favored at lower and midrange T and higher pCO2. Jagniecki et. al., (2015) refined the triple point (where all three solid phases are in equilibrium). On the basis of homogenization T derived from fluid inclusions in halite crystallized with nahcolite, this research assigned a range of 680 ppm to 1,260 ppm for atmospheric pCO2 during the early Eocene Climate Optimum (EECO) (~50-52 ma). This work lowers previous pCO2 estimates for the EECO from nahcolite and is aligned with pCO2 estimates from other proxies (paleosols, leaf stomata, and boron isotopes). The nahcolite proxy has also been applied to the deep past. Lowe and Tice (2004) have interpreted nahcolite, found as a primary evaporite mineral in Archean (3.5 -3.2 Ga) rocks of the Barberton and Pilbara cratons, as an indication of a high surface temperatures and elevated CO2 levels in the early Earth.
Perhaps, the most unusual of the oddball occurrences of natural sodium bicarbonate is the discovery of “fresh, well-preserved” nahcolite as micro- and nano-inclusions in diamond crystals collected from placers of the Juina area, Mato Grosso State, Brazil. Nahcolite is found with other carbonates (nyerereite, calcite) and minerals indicative of a carbonatitic-type paragenesis, possibly originating from the lower mantle or transition zone (Kaminsky et al., 2009).
Binocular microscope view of the interior of one of the “teeth” encrustations from my crystallization experiment. Many of the NaHCO3 crystals were prismatic or acicular, often in radiating masses. Although this crystal habit is favored by nahcolite, it is not obvious inspecting powdered baking soda. Magnification 20x. Photo by Ronald L. Parker
Binocular microscope view of elongate NaHCO3 crystals from my nucleation experiment displaying welldeveloped prismatic faces. Several of the prisms display terminations that are close to, but not 90° from, the c-axis elongation. In fact, the beta angle (between the a-axis and the c-axis) for this 2/m monoclinic crystal is ~93° Magnification 20x. Photo by Ronald L. Parker.
Nahcolite, has a multitude of applications in the domestic and industrial arenas of the modern civilized world. These many uses stem from the chemical nature of sodium bicarbonate to buffer pH change, to neutralize acidity, to provide a source of CO2 and to catalyze chemical reactions.
Some of the uses of sodium bicarbonate are familiar to everyone; many others are not. Here I am going to assemble a running list of these multitudinous applications, subdivided into familiar and unfamiliar. These lists were compiled based on the information from the Natural Soda website Chang (2002) and Graves and Qualmann, 2025.
Familiar uses of NaHCO3. Nahcolite, aka sodium bicarbonate or baking soda, is:
• Used as a leavening agent helping dough rise by producing carbon dioxide when heated above 50°C or in the presence of an acid catalyst like buttermilk or yogurt. The carbon dioxide bubbles are the cause of the rising or proofing. Baking soda also reduces the acidity of the baked good, improving flavor. Baking soda appears in the kitchen as a pure substance, but is also present in bakery products like tortilla, pancake, waffle, biscuit and cake mixes, self-rising flours and the fully-cooked bakery goods purchased from grocery stores.
Petrographic microscope photo of grain mount NaHCO3 crystals from my crystallization experiment. Several of the crystals show the angled a-axis relative to the c-axis elongation. Note the droplets signify incomplete desiccation. Magnification 40x.
by Ronald L. Parker.
• Used as the main ingredient in anti-acid medications that help to neutralize stomach acid thereby alleviating heartburn, indigestion and chronic ulcers.
• Used for odor control. Baking soda is wellknown as an odor eliminator and it is widely used to absorb and neutralize odors in refrigerators, closets, cat boxes and shoes. It is also found in natural deodorants.
• Used for cleaning. Baking soda has an uncanny ability to remove stains, dirt and grease from soiled surfaces. Cleaning grease and dirt is enhanced in alkaline solutions and this effect is
Photo
Figure 1 from USGS, 2009, showing the locations of the 58 nahcolite-bearing core holes from Rio Blanco County, Colorado utilized in the Resource Assessment. The red outline is the mapped extent of the nahcolite bearing zone. The USGS (2009) in-place nahcolite estimate for the 169,994 acres within the red boundary is ~ 43.3 billion short tons.
improved by odor control. It is used in dishwasher detergents and tablets and may other cleaning products around the household.
• Used as a common ingredient in toothpaste because it is a mild abrasive. The pH buffering capacity promotes stable, neutral pH which reduces halitosis.
• Used as a skin exfoliant.
• Used in skin creams and ointments for soothing bug bites, sunburns, and rashes. Less familiar uses of NaHCO3. Nahcolite, aka sodium bicarbonate or baking soda is:
• Used in making candy, food colors, food conditioners, breakfast cereals, starches and in refining sugar.
• Used as a pool chemical balance agent. Total alkalinity and pH balance in swimming pools is directly modified by baking soda addition.
• Used in water and wastewater treatment facilities to buffer pH, increase alkalinity and improve particulate flocculation for filtration.
• Used in water softeners.
• Used in bath beads, bath salts and bath bombs.
• Used in denture cleaners, as dental floss coatings and in mouthwash.
• Used in carpet cleaners and deodorizers, detergents and dry bleaches.
• Used in pharmaceutical applications.
• Used as a medicinal agent inhibiting the progression of chronic kidney disease.
• Used for mitigating the influence of lactic acid on muscle fatigue during high-intensity athletic training.
• Used in dry chemical fire extinguishers due to its ability to release carbon dioxide when heated.
• Used as a feed supplement to buffer acidity in the rumen of dairy cows. Also fed to beef cattle, broiler and laying chickens, and turkeys.
• Used as a soil additive to buffer pH and limit fungal growth in crops.
• Used as a raw material source of soda ash (Na2CO3). Soda ash is also used in a myriad of applications in the modern world, most significantly, in glassmaking. Although the most significant source of soda ash is the mineral trona (NaCO3-NaHCO3-2H2O), nahcolite is a close second.
Among the myriad uses of nahcolite is maintenance of swimming pool chemical balance. Weekly adjustment of Total Alkalinity (measured daily) is usually required for my neighborhood pool. When Total Alkalinity drops below 120 ppm, we add 7 lbs per 10 ppm upward shift. We will typically use ~100 lbs of NaHCO3 per season for our 47,000-gallon pool.
Photo by Ronald L. Parker.
• Used in drilling circulation mud to chemically remove excess Ca2+.
• Used in flue gas scrubbers to remove sulfate and other acid producing gases at coal-fired power plants.
• Used in the pulp and paper industry and in the manufacture of rubber and plastics.
• Used as an additive in fireworks.
• Used in fungicides and pesticides. A mix of sugar and baking soda will cause the internal organs of cockroaches to explode!
• Used to remove pesticide residues from apples.
• Used to polish silver.
• Used to remove mold and mildew from shower curtains.
You get the idea. There is almost nothing that this miracle substance cannot find a way to improve or interact with. A quick interrogation at the American Chemical Society website on baking soda returned 1433 articles.
Although nahcolite is mined around the world, one of the major producers is located in the Rocky Mountains, in the Piceance Basin - the company Natural Soda. Natural Soda is the only company extracting from the largest nahcolite resource in the world. Extraction is accomplished by solution mining – injecting hot water into nahcolite bearing substrata, then collecting the NaHCO3 bearing solution. Recovered water is brought by pipeline to a processing facility where it is cooled and crystallized. Impurities are removed. Water stripped of solids is reused, resulting in no wastewater discharges.
Nahcolite is known from global occurrence. Significant nahcolite resources are found in Botswana, Kenya, Uganda, Turkey and Mexico. Other notable locations are Mount Vesuvius, Italy (lava tunnels), Salar del Hombre Muerto, Argentina, the Kola Peninsula, Russia and, Mount Erebus, Antarctica. In the United States, the Parachute Creek Member of the Green River Formation in the Piceance Basin of Colorado contains one of the largest and most commercially significant nahcolite deposits. Searles Lake, California, also contains large quantities of nahcolite.
The next time you brush your teeth or bake cookies or wash your clothes or swim in a pool, you can thank nahcolite for making it all work out for you! And, don’t forget to celebrate National Bicarbonate of Soda Day on December 30th! (Graves and Qualmann, 2025).
APPENDIX
From chemistry classes, I knew that I could grow my own crystals by evaporating a supersaturated solution. I dissolved 167 g of Arm & Hammer
Baking Soda in 500 ml of distilled water on my kitchen stove. I then placed the warm supersaturated solution in a Pyrex cooking vessel with a chopstick suspending a thin string laced with “seed crystals” of NaHCO3, I set this up in front of an office fan to cool it and provide a uniform draft to facilitate evaporation. This configuration, right in my kitchen, was a source of amusement to my family. Over the next day, I also played with conditions – with no real objective except, perhaps, to induce changes in crystallization character. The initial fan setup yielded to extended proofing in the oven at 125°F, then a bout on the back porch in the sun. Altogether, it took about a full day to create crystal masses that seemed about right. A closer look with binocular and petrographic microscopes revealed pleasing details of crystal morphology that I was not expecting. I’ve included a few photographs of this effort – again, because there are almost no photos of nahcolite out there on the interwebs.
WEBLINKS
• https://www.webmineral.com/data/Nahcolite. shtml
• https://www.mindat.org/min-2831.html
• https://rruff.geo.arizona.edu/doclib/hom/nahcolite.pdf
• https://en.wikipedia.org/wiki/Nahcolite
• https://www.naturalsoda.com/
• https://www.youtube.com/ embed/_Ff_DtJKaCM
REFERENCES
• Bannister, F. A., (1929) The so-called ‘Thermokalite’ and the Existence of Sodium Bicarbonate as a Mineral, Mineralogical Magazine 22I124): 53-64. https://rruff.info/doclib/MinMag/Volume_22/22-124-53.pdf
• Brownfield, Michael E., Tracey J. Mercier, Ronald C. Johnson, and Jesse G. Self, 2010, Nahcolite Resources in the Green River Formation, Piceance Basin, Colorado, Chapter 2 in Oil Shale and Nahcolite Resources of the Piceance Basin, Colorado, USGS Digital Data Series DDS-69-Y https:// pubs.usgs.gov/dds/dds-069/dds-069-y/
• Chang, Luke L.Y., 2002 Industrial Mineralogy: Materials, Processes and Uses, Prentice Hall: Upper Saddle River, New Jersey, 472 pp.
• Eugster, Hans P., 1966, Sodium Carbonate-Bicarbonate Minerals as Indicators of pCO2, Journal of Geophysical Research, 71: 3369-3377. https://doi.org/10.1029/JZ071i014p03369
• Graves, Alice and Kate Qualmann, The Science of Baking Soda, website, https://axial.acs.org/ cross-disciplinary-concepts/the-science-of-baking-soda Accessed 6/2/25.
• Jagniecki, Elliot A., Tim K. Lowenstein, David M. Jenkins and Robert V. Demicco, Eocene Atmospheric CO2 from the Nahcolite Proxy, Geology 43(12): 1075-1078. https://doi.org/10.1130/ G36886.1
• Kaminsky, F. R. Wirth, S. Matsyuk, A. Schreiber and R. Thomas, 2009, Nyerereite and Nahcolite Inclusions in Diamond: Evidence for
Lower Mantle Carbonatitic Magmas, Mineralogical Magazine 73(5): 797-816. https://doi. org/10.1180/minmag.2009.073.5.797
• Lowe, Donald R., and Michael M. Tice, 2004, Geological Evidence for Archean Atmospheric and Climate Evolution: Fluctuating Levels of CO2, CH4, and O2 with an Overriding Tectonic Control, Geology 32(6): 493-496. https://doi. org/10.1130/G20342.1
• MINDAT, 2025, Nahcolite website, https://www. mindat.org/min-2831.html Accessed 2/21/25
• Natural Soda, 2025, website, https://www.naturalsoda.com/about-us/ Accessed 2/22/25
• USGS (2009) Nahcolite Resources in the Green River Formation, Piceance Basin, Northwestern Colorado, Oil Shale Assessment Project Fact Sheet, 2009-2011, 4 pp. https://pubs.usgs.gov/ fs/2009/3011/pdf/FS09-3011.pdf
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Ananya Singha is a student at University of Wyoming
Andrew Oordt is a student at University of Oklahoma
April Moreno-Ward is a student at University of Oklahoma
Branwen Berger is a student at University of Northern Colorado
Brendan Bialy is a student at Metropolitan State University
Brooklyn Dib is a student at Utah State University
Cade Evans is a student at University of Utah
Connor Smith is a student at Western Colorado University
Danghao Zheng is a student at Princeton
Daniel Kotowski is a student at University of Northern Colorado
Daniel Owodunni is a student at Lousiana State University
Deborah Agbamu is a student at Kansas State University
Diana Urda is a student at Texas Tech University
Donglin Zhu is a student at Colorado School of Mines
Dorothy Mwanzia is a student at Colorado School of Mines
Duke Ozamah is a student at Colorado School of Mines
Grant Barnes is a student at Colorado Mesa Univeristy
Harold Oppenheim is a student at Colorado College
Harper Peck is a student at Fort Lewis College
Ian Taylor is a student at University of Oklahoma
Isaac Pope is a student at Colorado School of Mines
Isabel Hopkins is a student at Colorado School of Mines
James Gutoski is a student at University of Colorado
Jessica Hiatt is a student at Colorado School of Mines
Juliana Kelley is a student at University of Colorado
Juliet Liscomb is a student at Montana State University
Keeya Beausoleil is a student at University of Idaho
Kiara Burgos is a student at New Mexico Institute of Mining and Technology
Lima Choiti is a student at University of Oklahoma
Liv Wheeler is a student at Montana State University
Logan Seymour is a student at Colorado State University
Luke Alder is a student at Utah State University
Luke Gezovich is a student at Colorado School of Mines
Madeline Ferguson is a student at Colorado School of Mines
Marwa Elshebli is a student at Oklahoma State University
Maureen James is a student at Colorado School of Mines
Micha Hernandez is a student at Utah State University
Mingxi Hu is a student at Penn State University
Montasir Akif is a student at University of Oklahoma
Morgan Sholes is a student at Colorado Mesa Univeristy
Muhamed Elshalkany is a student at Texas A&M University
Mustuque Munim is a student at Lousiana State University
Nicholas Borders is a student at University of Idaho
Rakan Alghamdi is a student at Colorado School of Mines
Sadie Almgren is a student at Colorado College
Sophia Werren is a student at Fort Lewis College
Wan Lo is a student at Penn State University
Zane Wasicko is a student at Western Colorado University
Daniel Blankenau with Great Plains Energy, Inc. from Lincoln, Nebraska
Liam Kaltenback with Core Geologic from Littleton, Colorado
Mat Beshears with Quantum Water and Environment from Lakewood, Colorado
Dave Clupper with Clupper Coloradompany llc from Oklahoma city, Oklahoma
James Coleman with Coleman Geological Services from Fayetteville, Geogria
Charley Thompson with GHP, Inc. from Thornton, Colorado
Xiaofei Pu with National Renewable Energy Laboratory from Arvada, Colorado
Rachael Hoover with Southwest Research Institute from Boulder, Colorado
John Reiland with TracerCo from Pasadena, Texas
Cari Johnson with University of Utah
Gerilyn Soreghan with University of Oklahoma
Manika Prasad with Colorado School of Mines
Paul Sylvester with Texas Tech University
Wendy Zhou with Colorado School of Mines
Henok Haile with CTL Thompson Inc from Denver, Colorado
Peter Barkmann with Colorado Geological Survey from Conifer, Colorado
Fabrice Demtare with Geo Squad from Golden, Colorado
Christine Turner with USGS from Morrison, Colorado
Jack Kenning with Fervo Energy from Littleton, Colorado
Christine Thomas with U.S. Department of the Interior - Office of Natural Resources Revenue from Kittredge, Colorado
RMAG and Dinosaur Ridge Booth.
WOGA Swing into Confidence: Golf Clinic.
DPC Breakfast Speaker Series.
RMAG Happy Hour.
RMAG Lunch.
WOGA Lean- In. RMAG Coffee Hour.
COGA Golf Tournament.
RMAG Family Hike Series.