A little juniper, and a bit of sage ...

Evelyn Mervyn at Georneys is hosting this month’s Accretionary Wedge -- the topic is Field Trip/Camp Moments:

“Share a fun moment from geology field camp or a geology field trip ...”

Having just returned from a road trip, it’s not surprising that the memorable moment that comes to mind is a recent one -- a night last week in the White Mountains of eastern California.  Amazingly, there was no fire ban in effect, and I foresaw an evening around the campfire, with dancing flashing light and comforting warmth.

Wandering up the slope behind camp, I picked up small juniper branches and a bit of sagebrush too.  Juniper burns hot and flashy, and both are sweetly aromatic.  Just a small fire is enough to keep the dark and cold away, to provide an added measure of security.  The sweet smoke seems to free deep memories ... maybe even hard-wired instincts of ancestors long ago for whom fire was so important, far more than just a pleasant addition to an evening in the mountains.

Stack twigs, then small branches.  Set a match to the wood.  Feed the little fire occasionally.  In the safety of its bright crackling warmth, let the mind drift.

After an afternoon communing with ancient bristlecone pines on really ancient dolomite, I had much to contemplate.  Some of the bristlecones have been growing for over 4000 years.  The dead go back even further, to almost 10,000 years ago.  Who was wandering through these mountains and building evening fires when these trees were young?  Surely people were gathering piñon nuts -- cones were abundant where I camped.  But would they have continued on up to 10,000 feet elevation, to where there were only stunted trees with tiny seeds?  I’m guessing not.  Contemplation of nature for its beauty and amazing stories must be a modern luxury.  We had to wait -- for both leisure time and the insights of science.

Two dead bristlecone pines on slope in mid-distance.  Dense bristlecone wood decomposes very slowly in this cold dry environment.  The dead may stand for thousands of years.

Of course, lifespans of even the oldest bristlecones are but the most fleeting of moments compared with the ages of the rocks around them.  The sandstones and quartzites of the Deep Springs Formation are ca 550 million years old.  The calcareous muds that became the Reed dolomite accumulated even earlier ... maybe 570 million years ago.

Quartzite of the Cambrian Deep Springs Formation.

Bristlecone pine on Proterozoic - early Cambrian Reed dolomite.

These rocks aren’t just old.  They’re special in that they were deposited at a time not well-represented in the rock record -- late Proterozoic and early Cambrian.  This is the gap that we in the western USA know as the Great Unconformity.  Seas had retreated westward, leaving much of western North America exposed to the elements.  Nothing was deposited, and erosion wore away at the landscapes, sometimes all the way down to Archean basement rocks.  But not here.  Today’s eastern California remained inundated in early Cambrian time, being west of the shoreline.  In fact, one of the most complete early Cambrian sequences in the world is found here in the White and nearby Inyo Mountains -- on the order of 20,000 feet thick.

Crest of the White Mountains -- high, dry and with lots of early Cambrian rocks.

Why are Paleozoic rocks so often described as “drab”?  They’re not as colorful as the sandstones of the Colorado Plateau, it's true, but the patterns and arrangements are quite striking.  I was easily lost in shooting them.

Back to the fire -- I occasionally added more wood, and let my mind drift.  Just imagine a sparkling shallow ocean in eastern California, with low hills barely visible on the horizon to the east in Nevada.  Strange little creatures wriggle in sand and mud that will become rocks of the Reed and Deep Springs formations in 550 million years or so ... wow, what a view!  As always, I was struck by the adventures that our minds can create for us.  We may not have complete stories of how these landscapes came to be, but take the information we do have, add a bit of human imagination and ... voilá! ... such wonderful experiences materialize!  I’m grateful to all the botanists and geologists who have helped tell these stories.

I am indebted to two authors in particular for making my recent trip so enjoyable.  Frank DeCourten’s Broken Land, about the Great Basin, is packed with pleasure for both the mind and the spirit (or soul, as DeCourten says).  Ronald Lanner also conveys a strong sense of love and amazement, as well as knowledge, in his wonderful Bristlecone Book.

For more on the ancient bristlecone pines of the White Mountains, see but there s life in the old dame yet, a post I put together after a visit there last spring.

Leaf Fairies ... and ghosts of travelers past

Fall aspen, just west of Fish Lake, Utah.

It’s the time of year when our mountain landscapes quickly change.  The Leaf Fairies have arrived and are hard at work painting leaves.  The trees become very colorful but also very still, and there’s an ominous sense of something about to happen.  I love fall, it’s beautiful, but there is always this odd discomforting feeling ...

Botanists say that aspen produce yellow pigments throughout the growing season, but that they are masked by the green of chlorophyll.  When chlorophyll production ceases for the year, yellow pigments take over, and the aspen leaves glow in the sunshine.

Sunny aspen leaves against dark volcanic rocks, Pelican Canyon near Fish Lake.

Some aspen make red anthocyanin pigments in fall -- these are the trees with orange and red leaves.   There's some evidence that anthocyanin production is clone-specific -- only certain stands of aspen will turn orange and red.  But anthocyanin synthesis also depends on adequate production of sugars during summer months.  Apparently leaf color is both genetic and environmentally-dependent ... according to scientists anyway :)

At Navajo Lake east of Cedar City, Utah, there were many red and orange aspen ...

... glowing in the morning sun.

Many of the high plateaus of central Utah are capped with volcanic rocks -- including the areas around Fish and Navajo Lakes.  The colorful fall aspen contrast nicely with the dark volcanics -- nice job, Leaf Fairies!

Aspen trees get all the attention, but there's plenty of color happening at ground level too.

The Leaf Fairies are working on the meadow rue.

Oregon grape -- obviously into anthocyanins.

Thistle rosette.

Wild geranium.

Fallen leaves litter the ground.  Another season of leaves, flowers and exuberant life is about to end.

My dog and I weren't the only ones on the trails.  Given the time of year, I was not terribly surprised to meet up with spirits of travelers past.  They seemed to be in a hurry, perhaps they're worried about getting to Pueblo de los Los Angeles before the snows arrive.  We know winter's not far off!

Ghostly pack train passes through aspen on the Fish-Lake cutoff between Santa Fe and Los Angeles.

I was thrilled to meet up with apparitions, but Sparky -- ever the practical dog -- wasn't impressed.