Thursday, December 29, 2016

2017 Wishes, Plans and a Resolution

Life ahead.
First …

Best wishes to all!! May your 2017 be filled with plants, rocks and good times. And fellow bloggers—please keep blogging! I would miss you if you quit.


Travel in a new-to-me field vehicle thanks to the uninsured driver who totaled my Honda CRV just before Christmas. No injuries, not much expense (thanks, Geico) and a low-mileage replacement CRV that doesn’t look like a baked potato.
Field vehicle and field assistant then …
… and now.

For tree-following, track an extinct palm tree, including a visit to its home on the shores of tropical Fossil Lake in southwest Wyoming (fertile imagination required).
Southwest Wyoming 50 million years ago (Chicago Field Museum).

Pursue life-long learning (antidote to aging says Mike the rock guy), specifically Basin and Range Volcanism at the University of Wyoming. Classes are free now that I’m 65! Expect volcanic posts.
Lunar Crater volcanic field in central Nevada.

Make a pilgrimage to the Central Coast of California in search of ophiolites, wildflowers, and lost youth.
Youthful days on the Coast of Dreams.

Return to South Pass (southern Wind River Range) in search of more rare rockcresses.
I will carefully search among Captain JC Fremont's "irregular lumps of clay."

And then—who knows? But I’m prepared, as this year I have a resolution: Always keep eyes, ears and mind open to new opportunities and adventures.

Still round the corner there may wait
A new road or a secret gate,
And though I oft have passed them by,
A day will come at last when I
Shall take the hidden paths that run
West of the Moon, East of the Sun.

Once I met a crystal unicornat Cottonwood Falls. Who would have guessed?!!

Monday, December 19, 2016

What are these rocks telling us?

“The heart of field geology is going up to rocks and getting them to tell you their stories” (source).
Beneath us are hundreds of feet of rock, often in layers that can be read like chapters in a book … if only we could see them! Fortunately, rivers sometimes come to our aid, cutting down through rocks to reveal their stories. Probably the most famous is the masterpiece cut by the Colorado River—the Grand Canyon. This is a story 1.75 billion years long, told in a stack of rocks a mile thick. The tale is fairly straightforward; sediments were turned to rock but otherwise not much altered. They remain mostly flat, like an immense layer cake.
Panorama from Point Sublime. WH Holmes, 1882. David Rumsey Map Collection.

But sometimes the reading isn’t so easy. Consider the cuts made by the Yampa and the Green, near their confluence on the south flank of the Uinta Mountains. I spent a long time pondering them, and never really understood the whole story. But I didn’t mind—it was a beautiful and remarkable place to be.
“Like an expression of frozen movement, or of time standing still, these faults accent the grandeur of the scene and stir wonder in the heart of the viewer.” Wallace Hansen, 1969
Confluence of Yampa and Green Rivers. View from Harpers Corner Trail, Dinosaur National Monument.
First I had to figure out which river was which. Fortunately I had help—the Harpers Corner Trail Guide (river labels circled: yellow – Yampa, green – Green).
The Green River flows south behind a long sandstone fin, is joined by the Yampa, and then turns back sharply to the north. In the photo below, the dashed arrow is the Green behind the long sandstone fin.
A Google Earth view helps:
These are crazy rivers!
The Yampa and the Green are thought to be superimposed drainages. There was a time when the Uinta Mountains were nearly buried in their own debris—sediments eroded off the range—and the Yampa and the Green flowed across the thick layer of debris as broad meandering streams. But then the region was uplifted, and erosion exhumed the buried mountains. The meandering rivers were “lowered” onto the underlying rocks, but they kept cutting down and maintained their circuitous paths! The Yampa is especially sinuous, winding for 22 miles through narrow canyons to cover less than ten air miles before joining the Green. [The whole story is more complicated; see Hansen 1986).]
Looking east up the Yampa River, above the confluence with the Green.
After making the sharp bend back north, the Green heads west and crosses the Mitten Park Fault, which it has exposed spectacularly for all to enjoy.
“Few faults anywhere are better displayed” (Hansen 1969). USGS photo, 1959.
These rocks started as sediments laid down on beaches, shallow sea floors, and in deltas and swamps, layer after layer. Next came humongous fields of sand dunes, and so on … for millions of years. The sediments were lithified, becoming a stack of mostly flat rock layers.

So why are they no longer flat? In fact, why are these rocks so severely deformed?! It's because they got caught up in mountain-building—specifically uplift of the Uinta Mountains between 70 and 40 million years ago.
Mitten Park Fault, NPS photo.
The folded rocks and fault were clear, especially with the trail guide to help, but the story behind them was not. This is not an easy read! The steeply-tilted rocks may be part of the local monocline—the huge step-like fold visible to the east. It’s broken by the Mitten Park Fault, with rocks to the east down-dropped relative to those to the west. Perhaps they were drug along the fault as the blocks moved past each other, creating the spectacular folds or enhancing those already there.
Monocline arrow marks change in dip from steep to gently-sloping.
Rocks left (west) of the fault are older and still roughly horizontal. Those at the same level to the right (east) are younger and severely deformed.
The timing is unclear. Some sources suggest the Mitten Park Fault came to be during the main uplift of the Uinta Mountains. Or it may represent a later stage, when the crest of the eastern Uintas collapsed (wow!). Movement may continue into the present.

In any case, these folded faulted rocks lay deep underground until the Green and Yampa Rivers finally cut down far enough to expose them.

Contrary to appearances, it wasn't a cataclysm that produced these tortuous rocks—just slow steady work. Crustal plates shifted a bit, rocks gradually folded, fractures grew inch by inch, maybe there was an occasional earthquake. This went on for tens of millions of years. Then the rivers went to work, slowly excavating dirt and debris, eventually exposing the rocks. But even with a plot this monotonous, a story tens of millions of years long can have a dramatic climax.
Having added a tiny bit of dirt from Mitten Park to its load, the Green continues on (NPS).

This is the last post from my September trip to the Uinta Mountains—a place I had long wanted to visit (~30 years) and finally did. Two weeks were only enough for an introduction; I need to return. Many thanks to Mike of CSMS GEOLOGY POST for the encouragement, and for recommending books to read, places to go, things to see.


Frishman, JA. 2011. Crest, Cliff and Canyon (blog), Geology of Dinosaur National Monument.

Gregson, JD, and Chure, DJ. 2000. Geology and paleontology of Dinosaur National Monument, Utah-Colorado: in Sprinkel, DA, Chidsey, TC, Jr. and Anderson, PB, eds. Geology of Utah’s Parks and Monuments. Salt Lake City: UGA Publication 28, p.155-188.

Hansen, W. 1969. The geologic story of the Uinta Mountains. USGS Bulletin 1291. PDF

Hansen, W. 1986. Neogene tectonics and geomorphology of the eastern Uinta Mountains in Utah, Colorado, and Wyoming: USGS Professional Paper 1356.

Untermann, GE, and Untermann, BR. 1969. Popular guide to the geology of Dinosaur National Monument. Dinosaur Nature Association. (out of print)

Saturday, December 10, 2016

In Search of a Tree

For almost a year I’ve followed a serviceberry tree 30 miles south of town, out in the Laramie Basin. What a surprise to find a serviceberry in a land of grass, sagebrush and greasewood flats! It was on the north side of a small ridge of tilted sandstone, in a tiny “forest” with aspen and cottonwoods, enjoying shade and tapping into water that accumulates in fractured bedrock. Yes, geology is destiny.

But too often I found it inconvenient to visit the serviceberry; I guess it exceeded my distance limit for convenience. So yesterday I set out in search of next year's tree in town, on the University of Wyoming campus. There were plenty of candidates.

My favorite was a palm. Yes, a palm tree in Laramie! It’s a plants-and-rocks kind of tree, specifically a plant in rock. But there’s no point in following this palm tree—it never changes. Or rather it hasn’t changed in the last 52 million years.
One of the many palm trees that grew on the shores of Fossil Lake 52 million years ago.
Fossil Lake was small compared to others, but the record it preserved is astounding!
The palm frond is in the Geology Museum. Actually it’s in the hallway, due to space constraints, along with other amazing fossils from the Green River Formation. The fish are most famous, but plants are well-preserved too, in beautiful detail.
Above and below, beautifully preserved veins (click on images to view).

Outside the museum, I wandered among the conifers that dominate university landscaping. They aren’t exactly exciting. Being evergreen, they don’t change much through the year. But one stood out—an unusual Colorado blue spruce next to the geology museum. It supplies cones to the resident Tyrannosaurus rex.
The amazing vegetarian T rex.
But amazing enough for a full year? Maybe not.

Next stop was the Williams Conservatory, where I entered a warm humid green world.
Most impressive was the Cook pine, which is about to burst through the roof. I liked the patterns made by the leaves. Cook Pine (Araucaria columnaris) is not to be confused with Norfolk Island Pine.

Another candidate was a fig tree, only about six feet tall. I love fig trees! The leaves have beautiful forms with contrasting shades of green, and fresh figs are really tasty. But since there were only a few figs, a taste test probably would be discouraged.

A stand of bamboo caught my eye. Bamboo is woody, and I’m fascinated by the idea of grass as tree. But it never blooms (I asked).

Two trees had the characteristic compound leaves of the legume family, with many leaflets neatly arranged. They made wonderful patterns against the roof of the atrium.
Above and below: rain tree or monkey pod … intriguing names!
The other legume was lead tree (Leucaena leucophylla) in the subfamily Mimosoideae. I’ve never shared habitat with the Mimosoideae, and would like to know more about it.
The lead tree was especially appealing because of the colors and patterns of leaves against the sky. But I saw no sign of flowers or fruit … so would it do anything? I asked the Conservatory Manager: No, it had never bloomed. But it was recently moved from more cramped quarters and seemed to be thriving in its new large sunny space, so maybe …
Lead tree’s simple but beautiful bark.

I explained my mission ("tree-following, an online thing") and waited for a reaction … “Cool!” So I asked which tree she would follow: “strawberry guava” (no hesitation). It blooms several times a year, and produces edible fruit which I would be welcome to harvest for photography and tasting. In fact, it was blooming yesterday …
 … and there were fruit, too. They looked brown and dry, hardly tasty. But I was assured there would be plump yummy red ones later on.
Then I saw one!
Holiday fun!
Strawberry guava (Psidium cattleyanum) is in the Myrtle family, and native to Brazil. It’s invasive elsewhere; in fact it's one of the 100 top invasive plant species. But the fruit are tasty and maybe I'll try strawberry guava leaf tea, also recommended.

So will I follow a strawberry guava in 2017? I'm not sure. That lead tree, with its photogenic leaves, is hard to resist …

December's gathering of tree-followers is underway, kindly hosted by The Squirrel Basket. Come join us!

Friday, December 2, 2016

A Pioneering Geologist on Uinta Plants


Required reading for my recent trip to the Uinta Mountains included several reports from early exploratory expeditions. The Uintas are rich in this kind of literature—the great pioneering geologists Ferdinand Vandeveer Hayden, Frank Emmons (working for Clarence King), and John Wesley Powell all passed through in the decade after the American Civil War. Their writing is scientific and filled with detail. But it's not boring, infused as it is with the excitement of discovery. Passing through the same landscapes, camping by the same rivers, pondering the same outcrops, I feel some of that excitement myself.

Though these men were geologists, they didn’t ignore plants. Usually they had a botanist along, or at least someone capable of collecting and preparing specimens. Those specimens that survived the rigors of travel were sent to experts, who studied and identified them, perhaps describing much-coveted “novelties”—species new to science. A plant list was included in the final report. The leaders themselves recognized the more common plants, and they often described the vegetation of the areas they passed through, in addition to geology, wildlife, natural resources, and any people they encountered.

In September of 1870, Ferdinand Vandeveer Hayden led his US Geological and Geographical Survey of the Territories into Brown’s Hole—the broad valley of the Green River in the eastern Uinta Mountains (now Browns Park):
“There is but little timber along the immediate valley of Green River—only a few bitter cottonwoods and willows; but on the hills there is a thick growth of the low piΓ±on and cedars. … in the valley, there is a universal growth of the sage, (Artemisia tridentata,) greasewood, (Sarcobatus vermicularis, ) and Linosyris.
When I visited Browns Park 146 years later, also in September, I found the vegetation much the same. There were occasional stands of bitter cottonwoods (today’s narrowleaf and lanceleaf) along the Green River, and pinyons and “cedars” (junipers) covered the hills. In the valley bottom, sagebrush and greasewood were extremely common. But Linosyris? I had never heard of this “universal growth” plant. Yet there was nothing common I didn’t recognize. Did geologist Hayden really know what he was talking about? Was Linosyris a misidentification?

A google search revealed that Linosyris grows in Asia, Europe and Great Britain. There are no species native to North America. But when I looked at images, I realized Hayden probably was correct … probably he was just another victim of nomenclatural change.

According to Google, the three plants below are called "linosyris." What very common plant of the basins of the American West do you think Hayden saw? [1. Type specimen of Linosyris (Aster) grimmii from Turkestan, MusΓ©um National d'Histoire Naturelle; 2. Galleta linosyris (“goldilocks”); 3. Linosyris villosa, Russia, maybe today's Aster oleifolius.]

As botany students, we’re repeatedly assured that scientific (Latin) names avoid the horrendous ambiguity of common names. But then when we go out into the real world, we quickly learn that these names change too, as taxonomists study and reclassify plants. To make things worse, experts don’t always agree. Old literature is especially challenging.

But Hayden’s Linosyris puzzle was easy to solve. In the “Catalogue of Plants” at the end of the report was Linosyris graveolens, under Compositae (Aster family). graveolens and compositae were the final clues. This is our rubber rabbitbrush, Ericameria nauseosa var. graveolens, which used to be a member of the genus Linosyris.

Rabbitbrush is extremely common in Browns Park. It definitely qualifies as “universal growth”—especially in September when it’s covered in flowers.
Bright golden floral displays can’t be missed.
Rubber rabbitbrush in morning sun.
Stems have a felt-like covering of dense white hairs.
As you may have guessed, rabbits like rabbitbrush. In fact, many wildlife species benefit from its abundance. Birds and small mammals use it for cover. Deer, antelope, elk, small mammals and birds feed on the leaves, flowers and seeds. Rabbitbrush is visited by a wide range of native insects, especially in late summer and fall. It’s said to support more native bee pollinators than any other cold desert shrub in the Intermountain West (Waring 2011).

Typical of the Aster family, what look like rabbitbrush flowers aren’t flowers. They’re small heads of tiny flowers, each with reproductive parts—stamens and pistils. [The Aster family was originally called Compositae because what look like flowers are actually composites. Not that long ago, it was changed to Asteraceae to be consistent with naming rules.]
The pungent flowers explain the scientific name, Ericameria nauseosa. But they're not that bad. I would say resinous rather than nauseating.
Flowers are tubular, less than a half inch long. Stamens and pistils emerge from the tubes. Source.

I took many photos of rabbitbrush in Browns Park … unintentionally. It was that common.
With dark dikes intruded into the ancient Red Creek Quartzite (more here).
With more rocks from the core of the long-gone Red Creek mountain range.
On a CO2 pipeline project (more here).
Approaching the Gates of Lodore on the Green River.
Rabbitbrush lined most of the roads in Browns Park, which isn't surprising since it thrives on disturbed sites. It often dominates initially, but in the absence of continued disturbance, becomes just a minor part of the native vegetation.
Above and below: rubber rabbitbrush along the Irish Canyon road, which cuts through the north flank of the Uinta Mountains near the east end of Browns Park.
Rabbitbrush is taking over the dugout where James Jarvie lived in 1880, his first year in Brown’s Hole.

In between Linosyris graveolens and Ericameria nauseosa, rubber rabbitbrush was called Chrysothamnus nauseosa. This is my choice of names because Chrysothamnus means “golden shrub”—which they certainly are! Rabbitbrushes are super difficult to classify, and experts surely will continue to rename them. Maybe someday some taxonomist will move rubber rabbitbrush back into Chrysothamnus, proving me prescient ;-)

Rubber rabbitbrush is the most complex of the rabbitbrushes, with 24 subspecies and varieties, many of which overlap or hybridize. Within these, there are multiple ecotypes, for example adapted to different soils. And within ecotypes there’s a “great deal of variability in morphological characteristics and chemical composition” (Scheinost and Ogle 2010). No wonder rubber rabbitbrush is so successful—so widespread and common. And no wonder rabbitbrush taxonomists struggle to classify them. In this case, maybe it’s best to use common names after all.
Rubber rabbitbrush and rainbow on my last day in Browns Park.


Anderson, L. 1995. The Chrysothamnus-Ericameria connection (Asteraceae). The Great Basin Naturalist, 55:84-88. Retrieved from

Porter, TC. 1871. Catalog of plants. in Hayden, FV. Preliminary report of the United State Geological Survey of Wyoming, and portions of contiguous territories. Washington: Government Printing Office. [Thomas C. Porter was professor of botany, geology and zoology at Lafayette College in Easton, Pennsylvania.]

Scheinost, PL, Scianna, J, and Ogle, DG. 2010. Plant guide for rubber rabbitbrush (Ericameria nauseosa). USDA-Natural Resources Conservation Service, Pullman Plant Materials Center, Pullman, WA. Accessed 2016, November 29.

Tirmenstein, D. 1999. Ericameria nauseosa. In: Fire Effects Information System [Online]. USDA Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory. Nomenclature updated 2014. Accessed 2016, November 29.

Waring, GL. 2011. A natural history of the Intermountain West; its ecological and evolutionary story. University of Utah Press.