Exploring the Earth and Sky of the West

Posts tagged “geology

Another Hidden Utah Gem: Pine Park

Pyramid-shaped white cliffs of tuff in golden sunset light
Intricately carved white rocks in a forest

Panorama overlooking Pine Park at sunset.

Tucked away at the terminus of a winding gravel road in the Dixie National Forest near the Utah/Nevada border, Pine Park would probably be a beloved national monument or state park were it located literally anywhere other than Southern Utah. We’ve been fortunate to come across quite a few places that fit this profile: stunning, unique, reasonably accessible, and—here’s the big one—empty. Places like Zion National Park may be bursting at the seams, but vast swaths of Southern Utah remain deliciously deserted. On a warm and beautiful weekend in early May, we had Pine Park pretty much all to ourselves!

Pyramid-shaped white cliffs of tuff in golden sunset light

Large Ponderosa Pines complement the smooth knobs of white tuff. 

The main draw at Pine Park are the spectacular rock formations carved into the Tuff of Honeycomb Rock. Tuff is a deposit of consolidated volcanic ash combined with rock, mineral, and glass fragments that forms only in very explosive volcanic eruptions. Pine Park sits on the margin of some of the most voluminous and expansive deposits of tuff in the world. Collectively, the thousands of feet of tuff scattered across large swaths of Nevada and western Utah represent a time when, for lack of a better descriptor, all hell was breaking loose across what is now the Great Basin. The Tuff of Honeycomb Rock is just a hair under 12 million years old, and thus one of the youngest deposits from this intense and violent episode of volcanism.

While the backstory of the tuff is intriguing, the real allure is the wonderland of creamy white spires, domes, and hoodoos emerging from the otherwise nondescript juniper, ponderosa, and piñon pine forest. Weathering and erosion have sculpted a masterpiece at Pine Park. In many places, the architecture almost resembles Bryce Canyon, albeit whitewashed, and with no maintained trails (several Forest Service trails wind through this area, according to the official map, but we had difficulty following them for any more than a hundred yards past the trailhead) the many pockets of eroded tuff are truly a blast to explore.

A single green pine tree emerge from cliffs of white rock

The Ponderosa’s don’t require much soil to gain a foothold in small depressions between ridges of tuff.  

Purple flowers grow in a sandy wash with rock formations in the background

This species of lupine (Lupinus aridus?) seemed to love the gravelly, sandy soil produced by weathering of the tuff.

A small pine tree grows in sculpted white rock

Fantastic rock formations immediately adjacent to our campsite. 

The tall, stately Ponderosas and a small stream give Pine Park a high-altitude feel, but in reality it sits at just 5700 feet above sea level, plenty low and warm enough for a plethora of wildflowers to be in full bloom during our visit:

Two white flowers with many petals and pink stamens

Bitterroot (Lewisia rediviva) are abundant on long-ago burned slopes above Pine Park, now home to open grasslands. 

Bright red cactus flowers

A claret cup cactus (Echinocereus triglochidiatus) in full bloom. I’m fully aware that the color appears somewhat enhanced on this photo, but it’s not; the claret cup flower really is that brilliant!

A cluster of purple flowers on a slope

The lupines were everywhere. 

Purple flowers growing from within a green plant and white rocks in the background

Everywhere!

Pink and brown boulders lie strewn in a chute of white tuff

Multicolored boulders litter a chute in the Tuff of Honeycomb Rock. 

 


Slots of Fun in Cottonwood Canyon

Multicolored sandstone ridges on Yellow Rock
Multicolored sandstone ridges on Yellow Rock

Multicolored Navajo Sandstone at Yellow Rock, Cottonwood Canyon, Utah

The 47 mile-long Cottonwood Canyon Road slices through some of the most otherworldly terrain in Southern Utah, connecting Highway 89 in the south with the Bryce Canyon region in the north. Mostly unpaved, some GPS devices have been known to lead travelers down this road in the name of a shortcut to Bryce Canyon National Park. When dry, Cottonwood Canyon makes for a wonderful scenic drive and is indeed a shortcut. But in the days following rain or snow, the layer of clay-rich shale the road follows for most of its length turns into a veritable morass, and renders the road impassible regardless of how many-wheel drive your vehicle might possess. Coming from the south, the road initially follows the broad valley of the Paria River drainage, before leaving the river behind and heading up the narrower valley of Cottonwood Creek. This portion of the road passes through Grand Staircase-Escalante National Monument; other sections used to as well before the monument experienced its recent “downsizing.”

We recently took a three-night camping trip to explore Cottonwood Canyon and some nearby areas. Our first stop was Yellow Rock, near the south end of the road about 13 miles from Hwy 89. Yellow Rock is a massive dome of Navajo Sandstone, easily visible from the road as is rises high above the jumble of rock layers alongside Cottonwood Creek. While the hike to its summit is not long, getting there requires a moderately-difficult scramble up a hidden rocky chute littered with loose boulders. Hiking poles/sticks highly recommended. After scrambling to the base of the rock, the real fun begins. After a few years living in Southern Utah, it is natural to assume that you’ve seen every color, pattern, and texture of sandstone that can possibly exist, but then Yellow Rock comes along and proves you wrong:

Yelow, red, orange, and pink swirls in the Navajo Sandstone

Walking up the east flank of Yellow Rock, enjoying the outdoor art gallery of beautiful colors, shapes, and patterns in the Navajo Sandstone. 

Multicolored sandstone and a view looking north along Cottonwood Canyon

Colorful sandstone near the summit of Yellow Rock, looking north towards Hackberry Canyon. 

Yelow, red, orange, and pink swirls in the Navajo Sandstone

Mesmerizing soft-serve patterns. 

While the abundant cottonwood trees lining the canyon bottom were still quite leafless, even in early April other signs of spring were beginning to show in this high desert. Traversing across Yellow Rock, we encountered many pockets of Desert Paintbrush, Anderson’s Buttercup, and Manzanita in sandy stream bottoms or in crevices in the sandstone, already in full bloom:

Bright red desert paintbrush plant.

Desert Paintbrush (Castilleja chromosa) growing in deep sand. The flower of this showy plant is actually the inconspicuous green spike at right; the bright red parts are the bracts and sepals. 

Orange and white spotted butterfly atop a yellow flower.

A orangetip butterfly enjoys the wild mustard buffet in the Cottonwood Canyon Narrows. 

Alternating bands of white and red rock.

For over a dozen miles, the Cottonwood Canyon road parallels the “Cockscomb”, a jagged ridge of resistant sandstone tilted to near-vertical. Here, varicolored rocks of the Carmel and Entrada Formations line the road near the Cottonwood Canyon Narrows trailhead. 

On our final night, we camped near the north end of the road, not far from Kodachrome Basin State Park, where we were treated to a spectacular sunset and even more stunning dark, moonless night skies:

Pink clouds and a band of pink rocky cliffs at sunset

Sunset from our campsite overlooking Kodachrome Basin.

Photo of the spring night sky with zodiacal light and Orion

Three landmarks of the winter night sky, Sirius (left), Orion (center, in flashlight beam), and the Pleiades (right) make their way towards the western horizon, where the bright band of the zodiacal light juts into the sky. 

No Southern Utah camping trip would be complete without a saunter through a slot canyon, so on the way home in the morning, we made a quick detour to Willis Creek Canyon. At the beginning of our trip, we had briefly probed the famous Buckskin Gulch, just south of Cottonwood Canyon in Arizona, but were quickly turned back by waist-deep mud & debris pools that were emanating quite possibly the most foul stench to ever besmirch this Earth. In contrast, Willis Creek Canyon is a rare bird in Southern Utah; a beautifully sculpted slot with no technical obstacles to rappel over, and no putrid cesspools to wade through. Instead, a small babbling brook winds through the sandstone narrows, seemingly oblivious to its own high-quality handiwork:

white and black streaked sandstone canyon walls

Narrows section of Willis Creek Canyon

A small stream flows between narrow sandstone canyon walls

Approaching a wide portion of the canyon. 

Narrow sandstone canyon walls

Back in the narrows!


Gold Butte National Monument in Pictures

Swirls of color on slickrock sandstone.
Sunset light on rock formations, Joshua Trees, and desert mountains.

A beautiful view from our camp in Gold Butte National Monument just after sunset, looking north towards the Virgin Mountains.

Gold Butte is one of our nation’s newest National Monuments, tucked away into a small corner of Southern Nevada, northeast of Lake Mead and snuggled up along the Arizona border. Unfortunately, Gold Butte was recently recommended for a “boundary reduction.” After spending a few days exploring the areas, I can confidently say that this is a truly stunning Mojave Desert landscape, home to amazing views, endangered wildlife, unique geology, and priceless relics of the past. If nothing else, I hope these photos demonstrate that this area is worthy of more protection, not less.

Joshua Trees and red sandstone rock formations

With abundant Joshua Trees, Creosote Bush, and stark rock formations, much of the landscape is vaguely reminiscent of Joshua Tree National Park, but with the colorful Aztec Sandstone providing a wonderful ruddy backdrop to the bright green Joshua Trees.

Late afternoon sunlight on sandstone rock formations and desert mountains

Late-afternoon view from a ridge overlooking Whitney Pocket, Gold Butte National Monument. You can just barely see our car next to the rocks at center right. 

Sunrise light illuminates Joshua Trees and colorful sandstone boulders. A notch in a sandstone boulder frames a view of a desert landscape.

Swirls of color on slickrock sandstone.

The Aztec Sandstone in this area is without a doubt the most colorful rock formation I’ve ever seen. Much like at nearby Valley of Fire State Park, around every corner are stunning swirls of color that would look more at home in a modern art gallery than in the desert. 

Red, pink, and yellow swirls in sandstone.

We found the most intense colors on un-weathered boulders associated with recent rockfalls. 

Fossil brachiopods in a limestone boulder with sunlit Joshua Trees in the background.

Many of the ridges and mountains in the Gold Butte area consist of Paleozoic limestones. Fossils, such as the brachiopods seen here, are a dime a dozen.

Petroglyph of a man that appears to be falling through space.

One of the primary justifications for the creation of Gold Butte National Monument was the abundance of rock art throughout the region. We saw petroglyphs pretty much wherever we went. The “Falling Man” seen here is perhaps the most well-known.

A large sandstone boulder containing numerous petroglyphs.

Petroglyphs, Gold Butte National Monument, Nevada.

Petroglyphs in the shape of Desert Tortoises.

More petroglyphs…Desert Tortoises perhaps?

Bright pink and yellow cactus spines

Lest we neglect the living, we also saw roadrunners, kangaroo rats (one inspected our dinner one night but successfully eluded being photographed) as well as burrows made by endangered Desert Tortoises and other creatures. Somewhat more stationary and easier to capture were the bright pink and yellow spines of the California Barrel Cactus (Ferocactus cylindraceus)

A small fishhook cactus growing in rocks.

A tiny fishhook cactus (Mammillaria tetrancistra) growing in rock rubble.

Several yuccas grow in sandy soil surrounded by sandstone rock formations.

Utah Yuccas (Yucca Utahensis) thrive in the thin sandy soils formed in alcoves within the Aztec Sandstone.

Large Joshua Tree with person for scale.

A large Joshua Tree (Yucca brevifolia) specimen.  

A raptor perches atop a Joshua Tree

I’m ornithologically-challenged; this appears to be some sort of hawk waiting patiently for it’s next meal from atop this Joshua Tree. If you know what it is, let me know!


The Many Faces of Limestone

Star trails over Notch Peak
Grotesque cave formations in Lehman Caves, Great Basin National Park, Nevada

Bizarre and grotesque cave formations in Lehman Caves, Great Basin National Park, Nevada

Limestone is a unique character is the rock world. There are only a handful of rocks that can be dissolved in water, and limestone is by far the most common of that group (other members include salt and gypsum). Most limestones are composed of the skeletal remains of deceased marine organisms (a handful are formed by entirely inorganic processes), so their presence generally indicates that an area was home to a warm, shallow sea at some time in the past. Fossils of coral, clams, snails, and other water-loving critters are often abundant in limestone, and in some ways, a chunk of marine limestone IS one gigantic fossil!

The aforementioned critters make their shells out of calcium carbonate, which is soluble in slightly acidic water. Most water on Earth’s surface is slightly acidic (due to interactions with carbon dioxide in our atmosphere) so interesting things can happen when water and limestone interact…especially if you give them lots of time! In particular, groundwater is capable of dissolving huge voids in limestone bedrock over long periods of time, forming features such as sinkholes and caverns.

Limestone is an abundant rock in our neck of the woods, especially in the mountain ranges astride the Utah/Nevada border in the Great Basin. Throughout much of the Paleozoic Era (541 to 252 million years ago), this region was covered by a series of vast, warm, shallows seas, much like the one that now draws millions to the Bahamas every year.

A great place to see limestone in action is the area around Great Basin National Park. Tucked away in extreme east-central Nevada, Great Basin is one of my favorite national parks, far removed from the hoards that descend annually on many of the west’s more well-known attractions. You have to make an effort to get here and at first glance, the Snake Range of Great Basin NP looks pretty much like any other mountain island rising up out of the Basin & Range. Upon closer inspection, it’s actually home to a stunningly diverse array of landscapes: The 2nd highest peak in Nevada (Wheeler Peak at 13,065 feet), some of the world’s oldest trees, and arguably the darkest night skies in the Lower 48 all reside here.

Various cave formations in Lehman Caves

Stalactites, stalagmites, draperies, shields, and other speleothems (cave formations) abound in Lehman Caves.

But limestone is ultimately the reason a national park exists in this corner of Nevada. A small portion of the area was originally set aside as a national monument in 1922 to protect Lehman Caves, a stunning cavern eaten into the 500 million year old Pole Canyon Limestone. Only in 1986 was the monument enlarged into a National Park encompassing both the caves and the surrounding mountain landscape.

While small in size, Lehman Caves is exquisitely decorated with a wide variety of speleothems (cave formations). Stalactites, stalagmites, shields, draperies, cave bacon, cave popcorn, soda straws, and helectites surround you at every turn as you wander through the cave. Photos show details not immediately visible to the human eye in the dimly lit cave, revealing an underground world that looks more like a well manicured sci-fi movie set than a natural place sculpted by nothing more than the water, limestone, and time.

Small stalactites aligned with fracture patterns in the limestone

Baby stalactites on the ceiling of Lehman Caves trace out fracture patterns in the Pole Canyon Limestone. Groundwater containing dissolved calcium carbonate seeps through these fractures, eventually emerging into the cave where the decreased pressure causes the calcium carbonate to precipitate out of solution, forming stalactites. 

Caves formations in Lehman Caves

Back on the surface, no trip to Great Basin NP is complete without a hike to admire some of the oldest living things on the planet: the Great Basin Bristlecone Pines (Pinus longaeva). Curiously, even these trees have an intimate relationship with the limestone that is so common here. Most of the bristlecone pine groves throughout the Great Basin are found growing on soils derived from limestone or dolomite (a limestone relative). For some reason, the bristlecones seem to prefer this rock type, perhaps because many other species do not, thus minimizing competition. The easily accessible grove on the flanks of Wheeler Peak (pictured below) is perhaps the most notable exception. Here the trees grow not in limestone, but among hard quartzite boulders deposited by old glaciers.

Scraggly bristlecone pine tree

Admiring a several thousand-year-old Bristlecone Pine (Pinus longaeva) in Great Basin National Park, Nevada

Ice and moss along a creek in Great Basin National Park

Early-season ice accumulation along Lehman Creek, Great Basin National Park, Nevada

About an hour east of Great Basin, slightly younger (~490 million years) limestone in the House Range forms another unique feature: Notch Peak. At just 9,658 feet, Notch Peak doesn’t measure up in altitude with many other summits in the region. It’s claim to fame is its 2,200 foot sheer northwest face, one of the tallest cliffs in North America. Where exactly it ranks on that list depends on your definition of “cliff,” but there seems to be little debate that it is the tallest limestone cliff on the North American continent. The peak is striking, especially when viewed from the west, where the full magnitude of its 4,000+ foot rise from the Tule Valley below is apparent.

Panorama of the House Range, Utah

The House Range and Notch Peak (right of center) at sunset. 

We spent an enjoyable evening camping in the shadow of Notch Peak and had hoped to hike to the summit the next day via Sawtooth Canyon on the east side, but unfortunately car issues derailed that plan.

Star trails over Notch Peak

Autumn star trails over Notch Peak, House Range, Utah. The mountains are lit by the light of a first quarter moon. 


The Heart of Utah: Capitol Reef National Park

Hickman Bridge, Capitol Reef National Park, Utah

Hickman Natural Bridge, Capitol Reef National Park, Utah

The least visited and most isolated of Utah’s five national parks, Capitol Reef hosts what is perhaps the quintessential Utah landscape. It is as if someone took small portions of the other four parks and mashed them into one; here you can find a plethora of arches and natural bridges, deep snake-like canyons, soaring Navajo and Wingate Sandstone cliffs, and even a few hoodoos thrown in for good measure.

Looking east across the Waterpocket Fold toward the Henry Mountains

Looking east across the Waterpocket Fold toward the Henry Mountains, the last mountain range in the lower 48 to be mapped and named, and their high point: 11,522′ Mt. Ellen.

The skinny sixty mile long park was originally established as a national monument in 1937, but became a national park in 1971. The odd shape stems from the inherent nature of the feature it protects: the Waterpocket Fold, a 100+ mile-long kink in the Earth’s crust known as a monocline. Creeks and rivers have dissected the fold over millions of years to reveal what is quite possibly the most colorful and diverse array of rock layers in Utah.

Capitol Reef is far from just about everywhere (which made the flat tire we experienced on the way that much more annoying). To the east and south lie the last major mountain range and river, respectively, to be mapped and added to the map of the lower 48 states. Not until the 1960s did a paved highway cross the Waterpocket Fold through Capitol Reef. In the northern part of the park, the Fremont River slices a narrow canyon through the Waterpocket Fold, its water creating one of the few habitable areas in the entire region. Petrogylphs attest to the importance of this year-round water source to ancient inhabitants. In 1880, Mormon settlers established the settlement of Fruita along the banks of the Fremont. The remains of this historic farming community and the abundant, lush green orchards and fields seem out of place in the otherwise stark central Utah canyonlands but add to the allure of the park.

Early morning in the Fruita orchards and pastures

Early morning in the Fruita orchards and pastures

Bighorn sheep petrogylphs along the Fremont River, Capitol Reef National Park, Utah

Bighorn sheep petrogylphs along the Fremont River, Capitol Reef National Park, Utah

Here are some of the sights from our quick trip to Capitol Reef this past weekend:

Patterns in colorful sandstone, Capitol Reef National Park, Utah

On a hike through Capitol Gorge, we encountered a bed within the Navajo Sandstone with some unbelievably complex and colorful patterns:

For the most part, the landscape at Capitol Reef is quite open, allowing vast views and superb light at sunset:

Chimney rock at sunset, Capitol Reef National Park, Utah

Chimney Rock, a tower of soft Moenkopi Formation mudstone capped by harder sandstone belonging to the Shinarump Member of the Chinle Formation

Sunlight on cliffs, Capitol Reef National Park, Utah

Late afternoon scene along the Chimney Rock Trail, Capitol Reef National Park, Utah

Sunlit cliffs at Capitol Reef National Park, Utah

More sunset scenes

Crumbling cliffs of Wingate Sandstone, Capitol Reef National Park, Utah

Hiking among crumbling cliffs of Wingate Sandstone, Capitol Reef National Park, Utah

Moon rising above cliffs, Capitol Reef National Park, Utah

A nearly full moon made it hard to do much stargazing at Capitol Reef, which is world-renowned for dark night skies.

Not far from the park campground and visitor center are the remnants of an old trail leading up a sandy wash, then up a short but steep talus slope before arriving at a hidden basin containing hoodoos and other strange rock formations. Unfortunately it was just about noon and the light was about as direct and harsh as possible, but it was cool to explore an area off-the-beaten path yet still in sight of the tour buses below:

Climbing up a talus slope, Capitol Reef National Park, Utah

Ascending the talus…

Balanced rock hoodoo, Capitol Reef National Park

Gravity-defying hoodoos were the reward!

Hoodoos at Capitol Reef National Park, Utah

Hoodoos in the Chinle Formation at Capitol Reef National Park, Utah


Colorful Geology at Valley of Fire State Park

Compaction bands and sandstone, Valley of Fire, Nevada

Compaction bands in multi-colored Aztec Sandstone, just one of many geologic wonders in Valley of Fire State Park, Nevada

One of the great things about living in Southern Utah is the abundance of different climates within a small geographic area. When temperatures rise into the 90s and 100s in the low-elevation valleys, we can be in cool alpine meadows at 10,500′ in less than an hour. When snow, slush, and mud cover the trails in winter, vast portions of the Mojave and Great Basin Deserts are within a day’s drive. One of these desert areas is Valley of Fire State Park in southern Nevada, not far from I-15 between St. George and Las Vegas.

Perhaps not surprisingly, upon arrival at Valley of Fire one is greeted with an array of whimsically sculpted red rock formations. Now red rocks are hardly unique in this part of the country, and the crimson cliffs here are no more notable than those found anywhere else in Utah or Arizona. But head into the interior of the park and you soon realize the allure of the Valley of Fire. After cresting the red cliffs, the hues begin to multiply exponentially and before long you are surrounded by just about every color of sandstone imaginable.

Colorful rocks at Valley of Fire State Park, Nevasa

A layer-cake of spectacular colors in Valley of Fire State Park, Nevada

To put it bluntly, the colors at Valley of Fire are simply ridiculous…and attributable to its unique geologic location. The rocks here are mostly equivalent to those found throughout southwestern Utah and the Colorado Plateau. The Aztec Sandstone, the dominant rock unit exposed in the park, is the equivalent of the Navajo Sandstone that makes up the cliffs of Zion National Park. Geologists just assign it a different name when it appears in Nevada and the Great Basin. Perhaps the distinct name is appropriate though, given that the sandstone seems to take on a life of its own here.

Valley of Fire State Park lies within the Basin and Range province, a vast region covering Nevada and portions of half a dozen other western states where the Earth’s crust is being slowly but violently stretched apart. As the writer John McPhee once noted, so much stretching has occurred here that 20 million years ago, Salt Lake City and Reno would have been more than 60 miles closer together. Faults are abundant in this land, and fluids associated with some of these faults have at various times leached iron compounds from the originally all-red sandstone, causing some layers to become bright white, and re-deposited them in other layers, leading to the wide variety of colors.

Some of the most impressive colors are found just to the west of the “Fire Wave” feature near the northern terminus of the park’s scenic drive:

Vibrant colors in the Aztec Sandstone in Valley of Fire State Park, Nevada

Vibrant colors in the Aztec Sandstone in Valley of Fire State Park, Nevada

Fire Wave in Valley of Fire State Park, Nevada

A feature known as the “Fire Wave,” Valley of Fire State Park, Nevada

While there are numerous hiking trails, there is also lots of off-trail terrain to explore. Some of the most spectacular scenery can be found by parking at one of the numerous pull offs and just wandering out into the rock wonderland. One particular geologic feature of note is what are known as “shear-enhanced compaction bands,” thin brittle fins of rock that rise almost vertically out of the ground and often run continuously for dozens to hundreds of yards. At first glance, these features look like mineral veins, but upon closer examination they are composed of the same material as the surrounding sandstone, but are obviously slightly harder than the host rock. In many places there are two perpendicular sets of the bands, forming a checkerboard like pattern superimposed on the sandstone.

Compaction bands in the Aztec Sandstone, Valley of Fire State Park, Nevada

Compaction bands in the Aztec Sandstone, Valley of Fire State Park, Nevada

The bands are the result not of stretching, but of compressional forces that predate the formation of the Basin and Range. Stresses associated with an earlier mountain building episode (known as the Sevier orogeny) created these funky bands by essentially “squeezing” together (and even breaking) the sand grains that make up the rock, eliminating much of the empty space between the grains and forming a miniature layer of tougher, harder, and more compact sandstone that is slightly more resistant to weathering and erosion. As a result, the bands tend to just out from the surrounding slickrock by several inches, and even several feet in some locations. For such a seemingly obscure feature, many papers have been written about these compaction bands (and similar ones in a few other locations in the region). However my understanding of the structural processes behind their formation is limited and the most recent articles about them appear to be behind a paywall. If anyone reading this has more insight into these things, I would love to hear from you.

As mentioned before, these bands are quite thin, in most less than a centimeter thick and thus, sadly, quite brittle. They are easily broken by an errant boot step so if you find yourself among them, tread carefully so that future visitors will be able to experience this unique and colorful landscape.

Colorful sunset on red rocks, Valley of Fire State Park, Nevada

Sunset from the Old Arrowhead Road in Valley of Fire State Park, Nevada

 

 


The “Caves” of Cathedral Gorge State Park

cathedral_gorge_badlands

The badlands of Cathedral Gorge State Park, Nevada

Next time you find yourself in extreme eastern Nevada with time to spare, I highly recommend checking out Cathedral Gorge State Park. This gem lies tucked away on the floor of Meadow Valley, about halfway between Las Vegas and Great Basin National Park, not far from the bustling hub of Panaca, Nevada. In other words, for a place fully accessible by paved roads, Cathedral Gorge is about as off-the-beaten path as you’re going to get.

Despite its under-the-radar status, Cathedral Gorge was established all the way back in 1935, and was one of Nevada’s four original state parks (along with the more well-known Valley of Fire north of Las Vegas). The highlight here is a shallow valley excavated out of a layer of soft lake sediments by Meadow Valley Wash and numerous small tributary streams. The sediment was originally deposited in a freshwater lake that called Meadow Valley home during wetter times in the Pliocene epoch (~2.5-5 million years ago). This area has been the epicenter for some pretty extensive volcanic activity over the past few dozen million years, so the sediment that accumulated in the lake was rich in volcanic ash.

Today, with the lake gone, the exposed sediment is so soft that it erodes extremely rapidly. Few plants can gain a foothold in earth that is crumbling so rapidly, so the water (and to a lesser extent, wind) have created a intricate landscape of badlands along the margin of the valley. The scenery is bizarre and not all that unlike what you might find in the famous badlands of South Dakota and the Great Plains. It definitely feels out of place in the sagebrush expanses of the Great Basin. While Cathedral Gorge bakes in the summertime, during our visit it was cold, windy, and virtually empty. We saw not another soul on a four mile loop hike around the perimeter of the valley.

cathedral_gorge_miller_overlook

Miller Point Overlook, Cathedral Gorge State Park, Nevada

cathedral_gorge_cave_3

The terminus of one of the narrow “mud slot canyons” in Cathedral Gorge State Park, Nevada

While the loop hike around the valley was enjoyable (if a bit windy), we didn’t stumble upon the highlight of our visit until we started poking around the rock formations adjacent to the trailhead parking lot. In a matter of minutes, we found ourselves exploring a landform that I still don’t have the right words to describe.

At the edge of the valley, runoff has carved a series of deep, extremely narrow, and almost perfectly vertical crevices into the soft sediments. The park calls them “caves” but the words cave, crevice, gully, crevasse, gorge, and ravine all fail to accurately capture their bizarre and truly unique nature. Perhaps the best way to describe them is as “slot canyons of mud.”

They evoke the sandstone slot canyons of Utah in the sense that they were so narrow that in many spots only a tiny sliver of blue sky could be seen overhead. Unlike most slot canyons though, whose delicate curves are clearly the result of flowing water, the walls here were angular and almost perfectly vertical. It was as if someone had carved huge blocks out of the mud with a chainsaw and then splattered the walks with mud to cover their tracks. Each little mud slot terminated abruptly in a roughly circular chamber whose walls were lined with linear grooves etched into the mud, extending all the way up to the rim. These chambers were clearly the work of waterfalls that spill into the canyons with each heavy rain.

As fragile and precarious as the mud walls looked, there were surprisingly few signs of catastrophic collapse. We explored about a half dozen of these little canyons, all of which were located right along the main road into the park. There were surely more that we missed, good enough reason to make the drive back to Meadow Valley another day.

cathedral_gorge_cave_1

Water flowing into the gullies erodes and redeposits mud, creating intricate shapes and patterns that line the walls.

cathedral_gorge_cave_2

Light streaming into a deep “mud slot canyon” in Cathedral Gorge State Park, Nevada


A Hidden Geologic Gem: Ashdown Gorge

alcove along ashdown gorge
alcove along ashdown gorge

Inside a spectacular alcove along Ashdown Creek. Alcoves such as these are numerous along Ashdown Gorge where the stream has eroded laterally into soft rocks near the canyon bottom. The perspective here makes the alcove appear a little deeper than it actually is, but the entire creek bed lies beneath the overhanging cliffs.

Not far from the increasingly overrun splendors of Bryce and Zion is a canyon frequently overlooked when discussing the many attractions of Southern Utah. The stunning Ashdown Gorge lies just a few miles from Cedar City off of Highway 14, yet I’ve seen a grand total of three other people on a pair of weekend hikes up the gorge this summer & fall. The solitude likely stems from the fact that there is no marked trail or trailhead for this hike; Ashdown Creek is the trail for a spectacular jaunt up the canyon. One must also scramble down the steep toe of an active landslide strewn with old vehicles, guardrail fragments, and asphalt chunks just to reach the creek bed from the highway. Once this has been accomplished though, it is fairly easily walking for many miles up the gorge as the water in the creek is typically only ankle deep except during spring snow melt and after heavy rains.

colorful scene along ashdown gorge

Beautiful colors in a narrow section of Ashdown Gorge.

Ashdown Gorge has a very different character than many canyons in Southern Utah, starting with the color of its walls. Not red or pink – the famous layers of Zion and Moab are well below the surface here – but rather varied shades of grey, tan, and yellow. The majority of the gorge is carved into the Cretaceous Straight Cliffs Formation, an impressive unit formed when southwestern Utah was a swampy coastal plain trapped between a disintegrating mountain range to the west and the shallow Cretaceous Interior Seaway to the east. Periodic but short lived rises in sea level are marked by occasional beds that contain almost nothing but fossilized oysters and other marine organisms.

Ripple marks on boulder, Ashdown Gorge

Not far from the junction of the gorge and Highway 14 is a gigantic boulder of the Straight Cliffs Formation displaying some of the best preserved ripple marks I’ve ever seen!

Ashdown Gorge is not quite a slot canyon, although it tries in places. Despite this, the walls for much of its length are several hundred feet high and there are many locations where you would NOT want to find yourself during a flash flood, so take a close look at the weather forecast before attempting to explore the gorge! Unlike the relatively hard sandstone that forms most of Utah’s famous slot canyons, the Straight Cliffs Formation is rather soft and crumbly. The creek has taken advantage of this by eroding laterally in many places. The result of this erosion is perhaps most spectacular around the outside edges of the many tight meanders of Ashdown Creek. Here the creek has carved into soft layers near the canyon bottom, undercutting harder layers of sandstone near the rim, creating vast alcoves that completely cover the creek bed.

Another alcove along ashdown gorge

Inside another alcove further downstream. Beneath this one were a plethora of large, partially pulverized blocks of grey rock that had clearly fallen quite recently (they had not yet been covered in the orange mud like most of the rocks in the creek bed) from the overhang above. We chose not to stick around in this one for long…

While walking along the creek, one thing that is striking is the color of the boulders upon which you walk. Not grey and tan like the canyon walls, but rather varying shades of orange, pink, and red. This is because Ashdown Creek drains the vast amphitheater of Cedar Breaks National Monument upstream to the east. The soft limestones and siltstones of Cedar Breaks are easily eroded, and Ashdown Creek can turn bright orange during even minor rains.

Flanigan Arch from Ashdown Gorge

Flanigan Arch from Ashdown Gorge

Another highlight of a hike up Ashdown Gorge is a good view of Flanigan Arch, an impressive span (reputable estimates of its length are hard to find, but most seem to say ~60 feet) that is difficult to access or even see from any other location.

In addition to the lack of crowds, the high elevation of Ashdown Gorge (7000-8000′) makes it a wonderful day hike (or potential overnight trip) for escaping the heat in summer (just watch for flash floods…) Ponderosa Pine, spruce, and fir are the most commonly seen large trees in the gorge which has a very “mountainous” feel to it. When we hiked it in late October, the temperatures were actually getting a little too cool to fully enjoy the numerous required stream crossings. In June when it was 80 degrees, the creek crossings were heaven!

Ripples in the creek in Ashdown Gorge

Some small riffles along Ashdown Creek.

small waterfall along ashdown gorge

Hiking up the gorge is fairly easy, a few small riffles and waterfalls can be easily scrambled around.


Rocks and (Musk)Rats of the Rockies

stream meanders along the Fall River, Rocky Mountain National Park, Colorado
stream meanders along the Fall River, Rocky Mountain National Park, Colorado

Textbook stream meanders along the Fall River, Rocky Mountain National Park, Colorado

A few weekends back I led my semester-ly geology field trip to Rocky Mountain National Park. Each time I end up finding new gems that I had previously overlooked, such as the spectacular stream meanders along the Fall River pictured above. One good flood and the stream will erode through the narrow strip of land separating the two meanders, leaving the bend in the middle of the photo high and dry. Places like this are a great opportunity for students to see in action a geologic process that every introductory geology instructor teaches in the classroom.

Despite many areas of the park still being covered in umpteen feet of snow, wildflowers are beginning to appear in the lower elevations around Estes Park:

Early blooming pasqueflower in Rocky Mountain National Park, Colorado

Early blooming pasqueflower in Moraine Park, Rocky Mountain National Park, Colorado

Longs Peak shrouded in a late-season storm, Rocky Mountain National Park, Colorado

Longs Peak shrouded in a late-season storm, Rocky Mountain National Park, Colorado

The biggest cause for excitement actually occurred after the field trip was over. I had intended to stick around in the park for a longer hike after setting the students free, but I quickly realized I had left my filled camelback on the kitchen counter. Lacking any sort of water carrying device, not wanting to shell out the cash to buy one, nor desiring to try to fashion one out of ungulate intestines, that plan was foiled. In lieu of a hike I headed for a short stroll around Lily Lake to try to get some pictures of the incoming storm enveloping Longs Peak.

While snapping the above photo, I was startled by what sounded like a cannonball being dropped into the lake behind behind me. My initial suspicion of hooligans launching boulders into the lake was discredited when I turned around and saw no one within half a mile. I made my way to the edge of the lake and remained motionless; after a few moments, this little guy appeared:

Muskrats in Lily Lake, Rocky Mountain National Park, Colorado

Beaver? Otter? Furry fish?

Lily Lake, Rocky Mountain National Park, Colorado

Lily Lake, Rocky Mountain National Park, Colorado

Noticing the presence of a nearby mass of chewed up sticks (above), I hastily assumed I was in the presence of a beaver. In short time, a second critter appeared and the pair began to tussle, albeit sadly behind a willow bush from my point of view. It soon became clear that these animals were more agile and less chunky and rotund than your typical beaver. Not being able to see them clearly with the naked eye, my next guess was river otter, which persisted until I got home and took a closer look at the pictures below. Otters would have a tough time leading their carnivorous lifestyles with only those gigantic incisors to work with. I was out of ideas (this is why I lead geology field trips, not wildlife watching trips…) , so I was forced to the internet where I learned that I had just seen my first muskrat.

Muskrats in Lily Lake, Rocky Mountain National Park, Colorado

Two combative muskrats in Lily Lake, Rocky Mountain National Park

Muskrats in Lily Lake, Rocky Mountain National Park, Colorado

Nice teeth!

Finally, on the way home, I made a quick stop at a rock shop in Estes Park that I’ve driven past dozens of times. I quickly discovered that knowledge of basic geological principles is not a prerequisite for owning a rock shop when I found a large bin of black limestone labeled:

estes_park_rock_shop

{facepalm}


A Sandstone Wonderland: Snow Canyon State Park

moqui marbles in snow canyon state park, Utah
moqui marbles in snow canyon state park, Utah

Thousands of moqui marbles, concretions of iron oxide minerals, accumulate in small troughs eroded into the Navajo Sandstone, Snow Canyon State Park, Utah

Southern Utah is a mecca for tourists from around the world, and most of that blame can be placed on the shoulders of a single layer of rock: the Navajo Sandstone. Quite possibly one of the most famous geological formations in the world, the Navajo Sandstone is responsible for the soaring cliffs of Zion National Park, the monoclines of Capital Reef, and the undulating, swirling, entrancing patterns of the The Wave in Arizona and Grand-Staircase Escalante National Monument in Utah. The Navajo Sandstone also rears its beautiful head in lesser known gems, such as Snow Canyon State Park just a few minutes northwest of St. George, Utah.

Snow Canyon is actually several canyons in one, all cut into the Navajo Sandstone. The original Snow Canyon existed up until about one million years ago, when it was rudely filled in by a series of basaltic lava flows originating from the northeast. Water, being the couch potato that it is, doesn’t like to carve through hard volcanic rock, so the stream that had excavated Snow Canyon promptly jumped ship to find some more Navajo Sandstone, and thus began establishing a new canyon slightly to the west. The stream went about its business carving Snow Canyon #2 until about 10,000-20,000 years ago, when it was thwarted by yet another lava flow. True to history, the stream changed course a second time, and is now busily carving Snow Canyon #3 even further to the west. The result is a multi-tiered canyon, with the remnants of the canyon-filling lava flows forming the tread of each step.

panorama of snow canyon state park, utah

360 degree panorama of Snow Canyon State Park from the top of a “turtleback” of Navajo Sandstone, a small knob of rock that was surrounded by basaltic lava flows that diverged around it during eruptions 10,000-20,000 years ago. The small dark black patch just to the left of center is the entrance to a lava tube. The current iteration of Snow Canyon is seen at left. 

The Navajo Sandstone itself is a colossal formation, several thousand feet thick in places, representing the lithified remains of a large Jurassic sand dune sea (known as an erg), likely analogous to the modern day Sahara desert. If you think Southern Utah is hot and dry today, imagine being there 180 million years ago when the climate was hot and hyper-arid. Add some dinosaurs and you’ve got yourself a fun day in the Jurassic desert. Over time, mineral-rich fluids percolated through the sand, depositing mineral cement in between the sand grains, binding them together into stone. The Navajo Sandstone is known for its spectacular aeolian (fancy geology-speak for “wind-blown”) cross-bedding, inclined layers that form when winds blow sand up the shallow face of a dune, only to have it tumble down the steep slip face on the other side.

cross beds in navajo sanstone, snow canyon state park, utah

Cross bedding in the Navajo Sandstone becomes even more pronounced as sunset nears and shadows lengthen

view of navajo sandstone ridges cliffs in snow canyon state park, utah

Looking south across swales and ridges of Navajo Sandstone from the Petrified Dunes trail in Snow Canyon State Park, Utah

A especially peculiar property of the Navajo Sandstone is the presence of occasional beds containing abundant spherical concretions of sand held together by the iron oxide minerals goethite and hematite (see photo at top of page). Commonly known as “moqui marbles,” these small spherules are slightly harder than the rest of the sandstone, so as the rock weathers away, the concretions are left behind to accumulate in large quantities on the surface of the rock. Moqui marbles can be found in many locations throughout Utah. And on Mars. The discovery of nearly identical hematite concretions by the Opportunity rover was some of the first definitive evidence that liquid water once flowed on the red planet, since the formation of the marbles requires groundwater to dissolve, and then re-precipitate iron minerals in the subsurface. If you are intrigued by my incredibly vague and simplistic description, you can find much, much more on the moqui marbles and their mode of formation here. If not, you are hereby forgiven and are welcome to enjoy the final photo without guilt:

black boulders of hematite rich beds in the navajo sandstone, snow canyon state park, utah

Hematite rich beds in the Navajo Sandstone are more resistant to weathering & erosion, forming large brown, black, and red boulders that are scattered across the landscape


Into the Valley of Death (Part 3): Canyon Combing

Colorful rocks in Gower Gulch, Death Valley National Park
Colorful rocks in Gower Gulch, Death Valley National Park

“Canyon of Color”: A walk through lower Gower Gulch reveals rocks in nearly every color of the spectrum

No tour of Death Valley would be complete without a peek into the myriad of mysterious canyons that slice abruptly into the mountain ranges surrounding the valley. When rain does bless Death Valley, it often arrives quickly and in large quantities, which can quickly turn a storm from a blessing into a nightmare. With little soil and few plants to soak up the water, most precipitation ends up rapidly draining into creeks and streams. Canyons that are bone dry 99% of the year can almost instantaneously find themselves channeling deadly flash floods, mudflows, and debris flows. Each time this happens, the canyons get slightly deeper (and the mountains slightly smaller) as the water picks up and transports bits of rock down to the valley floor where it dumps them in large piles known as alluvial fans. If the mountains weren’t continually being uplifted by tectonic forces (which most of the ranges in Death Valley are), this process would quickly erase the mountains from the landscape.

In October 2015 (just a few months before our visit), portions of Death Valley received several inches of rain in just a few hours, a nearly unprecedented storm for such a dry environment. Many roads were damaged or wiped out completely by floods and debris flows and portions of the park remained closed even several months later.

One of the most interesting canyons in Death Valley is Gower Gulch, located just south of Furnace Creek. Until recently, Gower Gulch was a small, run-of-the-mill canyon carved into the soft, buff-colored badlands of the Furnace Creek Formation. Things took a dramatic turn in the 1940s when the waters of the nearby (and much larger) Furnace Creek Wash were deliberately diverted into Gower Gulch in an attempt to prevent them from flooding populated areas downstream. With the drainage area of Gower Gulch enlarged by over 16,000%, periodic floods began to incise Gower Gulch at an alarming rate. The Gulch has deepened by more than 20 feet in just the last several decades, an erosion rate nearly unheard of in the geological world. The rapid erosion rate has caused some unintended consequences to overlooks, roads, and other park infrastructure but has simultaneously provided geologists with a fascinating window into what happens when you make a stream too big for its own britches.

Colors in Gower Gulch, Death Valley National Park

Late afternoon sunlight bathes the cliffs above Gower Gulch in golds, pinks, and oranges. Note the mud line on canyon wall.

Gower Gulch had experience once of these erosive floods just a few months prior to our visit. The lower walls of the canyon were still coated in a thin layer of tan mud left behind by the October 2015 floods. In many cases, the mud line was 10-15 feet high. Little imagination was needed to realize that Gower Gulch would be a terrifying place to be during such an event!

Flood deposits in Gower Gulch, Death VAlley National Park

Two different types of flood deposits in Gower Gulch; multicolored gravel originating from Furnace Creek Wash, and buff-colored mud from the badlands surrounding the gulch. 

An hour north of Gower Gulch is Mosaic Canyon. Cut into the Panamint Mountains the rise to the west of Death Valley, Mosaic Canyon also experiences mudflows and debris flows during intense rains. The bedrock of the canyon is ancient dolomites, limestones, and marbles; in many places, these rocks have been polished to a shine by floodwaters roaring through the canyon.

The highlight and namesake of the canyon though are the spectacular deposits of breccia (a sedimentary rock made of coarse-grained, angular rock chunks cemented together by a finer-grained matrix) that have been pasted onto the canyon walls by repeated debris flows. The high carbonate content of the rocks allows percolating water to quickly cement the debris flow deposits together into a solid layer that can adhere to the canyon walls. The fragments of rock within the breccia are a representative sample of those that comprise the Panamint Mountains, and thus vary widely in color making the breccia appear like a complex fresco created by a powerful force of nature.

Colorful breccia in Mosaic Canyon, Death Valley National Park

Mosaic Canyon gets its name from the colorful breccias that coat much of the canyon wall. 

breccia in Mosaic Canyon, Death Valley National Park

More breccia in Mosaic Canyon, Death Valley National Park

Breccia and marble, Mosaic Canyon, Death Valley National Park

Colorful breccia fills a depression carved into the polished marble walls of lower Mosaic Canyon, Death Valley National Park

One can hike up Mosaic Canyon (some moderate scrambling required) for about a mile and a half, admiring the rock formations, before coming to a ~50 high cliff (a waterfall during wet periods) that inhibits further upstream travel. Hiking up Mosaic Canyon is truly spectacular, each bend reveals a new assortment of geological treasures, only some of which are pictured here.

Looking down Mosaic Canyon, Death Valley National Park

A hike up Mosaic Canyon ends here unless you have a rope; behind me is a 50′ dry waterfall

Rock patters in Mosaic Canyon, Death Valley National Park

The character of Mosaic Canyon change with every bend!

 


Into the Valley of Death (Part 2): Ventifacts and Dunes

View of Black Mountains from Ventifact Ridge

Wind gets far more credit for shaping the surface of the Earth than it should. Contrary to popular belief, wind is a relatively poor sculptor of landscapes, especially when compared to water in its many forms.

Remove water from the equation though, and the influence of wind becomes magnified. The planet Mars is a great example. Dry for billions of years, with no streams or ocean waves to shape its landscape, Mars has become a barren land of sand dunes and sandblasted rocks.

If you want to experience a Mars-like landscape without the inconvenience of a long flight, Death Valley just might be your best bet. Here, water is so sparse that the effects of wind are more prominent and striking than anywhere I’ve ever visited.

Death Valley and Telescope Peak from Ventifact Ridge

Martian-like landscape on Ventifact Ridge, Death Valley National Park. A snow-dusted Telescope Peak (11,043′) is visible in the background.

View of Black Mountains from Ventifact Ridge

Looking east along Ventifact Ridge toward the Black Mountains

My personal favorite wind-driven geologic phenomenon are what are geologists call “ventifacts.” Ventifacts are rocks (usually boulder-sized) that have essentially been sandblasted by wind-blown sand particles for extended periods of time. Ventifacts are consequently pockmarked with an array of pits, grooves, gouges, striations, and etchings that betray their uncomfortable past. Near Badwater in southern Death Valley, a low, linear ridge covered in boulders of dark black volcanic rock juts out into the valley, intercepting the strong winds that often blow along the valley’s length. Nearly every rock on this ridge shows these telltale signs of sandblasting. Combined with the lack of vegetation, photos from here resemble many of those taken by the Mars rovers more than just about anywhere else on Earth.

Ventifact and sand ripples, Death Valley National Park

Ventifact and sand ripples, Death Valley National Park

Close up of sandblasted ventifacts in Death Valley

A pair of excessively pockmarked ventifacts. Note that the top portion of the foreground ventifact has been completely eaten away near the top.

Larger ventifacts like the one below often take on an exceptionally strange shape. This is because wind (even very strong wind) is incapable of picking up anything bigger than a large grain of sand, and even then it can’t lift it more than a few feet off the ground. The result is that the bottom two or three feet of the bounder gets abraded away, while the top remains relatively intact, leading to the classic “hourglass” shape of large ventifacts.

Man standing on ventifact

Yours truly atop a large roadside ventifact in Death Valley

All of the sand blown along the valley has to go somewhere. In several locations around Death Valley National Park, mountain ranges act as obstacles to wind, and where the wind stops or slows, the sand is deposited in large dune fields.

Death Valley has not shortage of dunes but the most accessible are the Mesquite Flat Dunes near Stovepipe Wells. Unfortunately, the proximity of these dunes to paved highways means that they are also one of the most visited locations in the park. Upon arrival at the dunes a bit before sunset, we were immediately greeted by the high-pitched insectile buzz of an amateur drone (currently prohibited in national parks) hovering overhead. Fortunately, such devices have a limited range and we were soon free of the annoyance. Even though the Sun was getting low, our plan was to stay awhile. Before long, the Sun set, the stars came out and we had the dunes almost entirely to ourselves as the nearly full Moon illuminated our path:

Death Valley sand dunes with stars

A clear winter night in the Mesquite Flat Sand Dunes, Death Valley National Park. The yellowish glow on the horizon at right is light pollution from Las Vegas, nearly three hours away.

Ripples in sand dunes, Death Valley

Ripples in the sand, Mesquite Flat Sand Dunes, Death Valley

One unique feature of the these dunes is the presence of large patches of dried & cracked mud between the dune crests. Having been to dozens of different sand dunes, seeing anything other than sand (and the occasional hardy bush) in a field of sand dunes in a strange sight. The origin of the mud is connected to the fact that the dunes lie nestled against the base of the Panamint Mountains. Periodically, mudflows and debris flows burst forth from the canyons at the foot of these mountains, migrating their way into the low spots between the dunes. The mud dries quickly in the arid climate, forming the large mudcracks. The sand dunes, constantly in a state of motion, eventually bury most of the mudflow deposits, leaving only portions peeking through.

Mudcracks and sand dunes at night, Death Valley

Mudcracks in the Mesquite Flat Sand Dunes, the dried remains of mudflows from the Panamint Mountains that occasionally penetrate the dunes. The Pleaides star cluster is visible near the top of the photo.

Coming up in part three, we leave the valley behind and explore the myriad of canyons cut into the mountains ringing Death Valley. Then it’s on to Joshua Tree!


Fun in the Fort Collins Foothills

Horsetooth Rock

Horsetooth Rock, a famous Fort Collins landmark, is composed of hard Precambrian pegmatite.

It is currently snowing so hard I can barely see across the street. Fortunately, I haven’t been able to say this very often this winter, and I strongly suspect it won’t even be true 10 minutes from now. After six winters in the Pacific Northwest, once again residing somewhere where “warm” and “dry” are not mutually exclusive weather conditions has been quite refreshing. The mild weather has made hiking and all the other outdoorsy things that are practically a prerequisite for obtaining a Colorado driver’s license quite enjoyable. I’ve written about some of my adventures up to Rocky Mountain National Park but have yet to share any photos of our more immediate surroundings here in Fort Collins.

Fort Collins itself, lying at the extreme western edge of the Great Plains, is…well…flat. The only sledding hill I’ve yet seen here is a pathetic 20 foot run down the side of a large pile of gravel in the corner of the college football stadium parking lot. (As you’ll notice though, there is very little snow in any of these photos, so this is sort of a moot point.) Immediately west of town though lie the foothills of the Rocky Mountains, a beautiful landscape of ridges and valleys that mark the boundary between the plains and the Rockies.

Fort Collins at sunset

Overlooking Fort Collins just before sunset from cuestas (ridges) between town and Horsetooth Reservoir.

Lichens on sandstone boulders

Colorful lichens coating sandstone ledges of the Cretaceous-age Lytle Formation, Coyote Ridge Natural Area.

Geologically speaking, the foothills are fascinating (though geologists find just about any landscape fascinating…heck even Iowa has one of the largest asteroid impact craters on Earth lurking just beneath its surface) because they  represent where the Rocky Mountains pushed their way up through the crust. Prior to the uplift of the Rockies, this portion of Colorado was covered in a thick, continuous stack of colorful but more or less flat-lying sedimentary rock layers, much like one sees at the Grand Canyon today. Eventually, the Rockies thrust their way upward through the sedimentary rock, forcing the formerly flat layers to tilt toward the east. Over time, the softer sedimentary layers were (relatively) easily eroded away, forming long north/south trending valleys. Other layers were harder and resistant to erosion, forming dramatic sloping ridges known as cuestas and hogbacks that parallel the valleys.

The resulting pattern of alternating ridges and valleys is striking and has practical uses as well. In many places, streams flowing out of the mountains have been dammed at the point where they slice through the ridges, forming long, slender reservoirs that flood the valley bottoms. Horsetooth Reservoir, which provides some drinking water for Ft. Collins and irrigation water for the plains, is perhaps the best example.

Devils Backbone hogback

Devils Backbone, a nearly vertical hogback of Dakota Sandstone south of Fort Collins.

Slightly further west, the landscape changes as the sedimentary layers give way to the igneous and metamorphic rocks that compose the bulk of the Rockies, forming famous local landmarks such as Horsetooth Rock (above) and Arthur’s Rock.

The plethora of city, state, and county parks that protect large swaths of the foothills are increasingly important as the cities below the foothills encroach on wildlife habitat. Mammals like deer, elk, bobcat, and bear are abundant in the foothills. As the cities below continue to push up against, and even into, the foothills, it’s not uncommon to read stories in the local newspaper about a moose, bear, or mountain lion wandering into town.

Mule deer on cliff

Mule Deer, Maxwell Natural Area

Black-tailed prairie dog, Coyote Ridge Natural Area

Black-tailed prairie dog, Coyote Ridge Natural Area

Cottontail rabbit in snow

Cottontail rabbit, Coyote Ridge Natural Area

Eagles Nest and Cache la Poudre River

Eagles Nest Rock and the North Fork of the Cache la Poudre River

Mahoney Park, Bobcat Ridge Natural Area

Mahoney Park, Bobcat Ridge Natural Area


(Petrified) Forests of Stone

Close-up of log of petrified wood
Close-up of log of petrified wood

Despite being comprised almost entirely of quartz, trace amounts of elements like iron and manganese give petrified wood its myriad of colors.

I grew up about 90 minutes away from Petrified Forest National Park and, aside for a quick lunch stop about 10 years ago, had never visited before last week. While this is nowhere near as inexcusable as living in Arizona for decades and never visiting the Grand Canyon (yes, such individuals exist…I’ve met many), it still seemed like a bit of an oversight on my part. Or it could simply be a reflection of the inordinate number of outdoor activities that exist in northern Arizona; even living in the area for 10+ years isn’t enough time to hit everything. Either way, after finally venturing into the Petrified Forest, I can emphatically say that it should be mentioned with the best that northern Arizona has to offer.

Located amongst the vast Painted Desert of northeastern Arizona, the main attraction of Petrified Forest is of course the petrified wood. The formation of petrified wood is initiated when downed trees are quickly buried by sediment. Once entombed in the sediment, the lack of oxygen prevents the logs from decaying as they normally would when exposed directly to the atmosphere. In this case, the logs (none of which remain standing, despite the name “Petrified Forest”) were likely brought here in massive logjams along an ancient river system that existed during the Triassic period. A combination of sediment from the river and ash from nearby volcanoes buried the logs, not to be seen again for more than 200 million years. During this time, as the logs became buried under an increasingly deep pile of overlying sediment, dissolved silica began to crystallize in the pore spaces of the wood as quartz, eventually replacing all of the organic material while maintaining the original shape and structure of the log.

Brilliantly colored petrified wood fragment

A brilliantly colored petrified wood fragment.

Petrified wood is not particularly rare. Good examples abound in Yellowstone National Park, Washington state, Utah, Colorado, Oregon, Alberta, New Zealand…the list goes on and on. What makes Petrified Forest National Park unique is the quantities found here. Due to the aforementioned Triassic log jams, large quantities of wood were concentrated in small areas. In a location known today as Jasper Forest (see photos below), movement was not possible without walking over a nearly uniform carpeting of small petrified wood fragments and frequently having to clamber over 2-3 foot diameter logs. Truly stunning!

Petrified wood in the Jasper Forest

Petrified wood in the Jasper Forest, Petrified Forest National Park.

Overlooking the Jasper Forest at sunset.

Overlooking the Jasper Forest at sunset.

Another unique aspect of Petrified Forest is the colorful canvas on which the wood is found. The wood is eroding out of a rock unit known as the Chinle Formation, which essentially consists of all of the river sediment and volcanic ash the buried the trees in the first place. More than 1000 feet thick in the park, the Chinle Formation is composed primarily of extremely soft mudstones, clays, and volcanic ash. Water is able to easily sculpt the soft rock into fantastically colored and oddly shaped badlands that make a spectacular backdrop for the logs.

Chinle badlands

The soft muds and clays of the Chinle Formation are easily eroded, forming badlands-like topography throughout the Painted Desert.

Colorful badlands in the Chinle Formation

Colorful badlands in the Chinle Formation at Blue Mesa.

Petrified Forest National Park faces an issue not encountered by most other national parks, namely, the wholesale theft of the very resource it was established to protect. For this reason, the park is only open during daylight hours (from 8-5 in the winter) to minimize opportunities for looting. It strike me as very sad that such measures are necessary. With a little geological perspective, it becomes clear how incredibly lucky we are to experience a landscape like Petrified Forest at this moment in time. So easily eroded is the Chinle Formation that in many locations, several inches of it are removed each year. This may not sound like much, but geologically speaking, that’s a veritable bullet train of erosion. While it took tens of millions of years for the Chinle to be deposited, it will be erased from our planet by the unceasing forces of weathering and erosion in a tiny fraction of that. The petrified logs, being comprised mostly of silica, are harder and will last a little longer, but are still brittle and will eventually be washed into the Little Colorado River and swept downstream along with the colorful Chinle badlands.

What all this means is that the colorful Painted Desert/Petrified Forest landscape we see today is one that is extremely temporary. While this is true of most landscapes we see on Earth today—our planet likes to re-build, re-arrange, re-shape, and remove constantly—the Painted Desert is even more ephemeral than most. While mountain ranges comprised of harder, erosion-resistant granite or quartzite (like most of the Rockies) can stand the test of time to some degree, the longevity of the Painted Desert, its soft sediments, and its brittle petrified wood is comparatively brief. Stealing this treasured natural resource only abbreviates our time with the Petrified Forest even more.

Petrified wood in the Chinle Formation

Pieces of petrified wood accumulate in small hollows in the extensively gullied Chinle Formation.

Petrified logs in a small wash

The soft sediment surrounding the logs is easily transported away by small streams and washes.

Petrified wood and quartz on pedestals

Relatively hard chunks of petrified wood and quartz protect the softer sediment of the Chinle Formation from erosion, forming pedestals small…

Large piece of petrified wood in pedestal.

…and large!

 


A Photographic Journey Down Chuckanut Drive

Chuckanut Drive, a.k.a. Washington State Route 11, is one of the premier attractions here on the extreme northwestern fringe of the U.S. “The Nut”, as I like to call it, winds for just over 21 miles between Bellingham and Burlington. Hemmed in by the Chuckanut Mountains to the east and numerous scenic bays, inlets, and islands on the west, it offers a stunning variety of scenery for such a short stretch of road. Chuckanut Drive has truly been a gift to me the last year and a half, because I can be cruising down it (well, as least what passes for “cruising” in a 16 year old Corolla…) and taking photos within 5 minutes of leaving my house. I’ve done this several times recently, now that the Sun is once again gracing us with its presence past 4pm.

Chuckanut Drive is chock full of destinations that make you feel further from civilization than you actually are, places that are perfect for occasions when time is in short supply. One of my favorite such spots is the beach walk at Chuckanut Bay. Fortunately for me, it also happens to be one of the closest, sitting just barely inside Bellingham city limits. Close enough for me to walk if I was feeling ambitious. Nearly inaccessible at high tide, once the water level drops a couple of feet, a few hundred yard stroll to the northwest shore of the bay puts you in the middle of spectacular and bizarre rock formations sculpted out of the Chuckanut Sandstone by freezing sea spray that accumulates along the margin of this sheltered cove. This is also a great place to see honeycomb weathering features along the shore, as is adjacent Teddy Bear Cove.

Low tide critters at Chuckanut Bay

I’m not sure what sort of critter makes these little volcano-like structures, but they are all over the place at low tide in Chuckanut Bay, one of my favorite local spots for photography.

Rock formations along the Chuckanut Bay Walk

Some of the intriguing and bizarre rock formations along the Chuckanut Beach Walk.

Chuckanut Drive is heaven for the geologically inclined for a couple of reasons. For one, the road itself is built on layers of weak sandstone that slope precariously towards the sea. When it rains, water seeps into the spaces between the layers, dramatically decreasing something called the coefficient of static friction, which is normally responsible for keeping the rock intact. In other words, the water essentially lubricates the surface between rock layers, causing causing large chunks of the hillside to frequently slough off, making Chuckanut Drive one of the most landslide prone highways in the state. Last winter, it seemed like the road was closed at least every few weeks in order to repair large gashes in the pavement caused by falling boulders.

Two, the sandstone exposed here, a rock unit known as the Chuckanut Formation, is chock full of fossilized ferns, palm fronds, gingko leaves, wood, and bark, relics from a time when the Pacific Northwest was just as wet as today, but a whole lot warmer. An exposure of this same rock unit an hour to the east even turned up a footprint of a giant Eocene flightless bird a few years back, which is now on display at Western Washington University.

A few miles further south of Chuckanut Bay is Larrabee State Park, the first state park in Washington, whose landscapes and marine life I’ve documented previously and continues to be a favorite spot to catch the sunset:

Sunset at Larrabee State Park

The Sun dips behind the San Juan Islands as seen from Larrabee State Park.

Sunlight streams through the fog along Chuckanut Drive
Winter brings frequent morning fog to the coast of NW Washington, but it usually starts to burn off around mid-day. 10 minutes after I took this photo, the fog was gone, replaced by sunshine and a clear blue sky. 

Heading south from Larrabee State Park, the road becomes increasingly curvy and narrow as it clings to the hillside passing oyster bars, cascading waterfalls, and smattering of million-dollar homes. (You never actually drive along the coast proper, that route is reserved for the Burlington Northern Railroad, but the views are even better as a result.) Keep your eyes on the road and wait for one of the plethora of pull-offs where you can take it all in without running the risk of driving off a cliff.

A short but steep hike from near the route’s southern end puts one at Samish Overlook, which offers unparalleled views of the San Juan Islands, the Skagit River Valley, Olympic Mountains, and even Mt. Rainier on a clear day. On days when the winds are right, this is a launching point for local paragliders. It’s also a cool place to go during a foggy spell; at nearly 1300 feet above sea level, the Overlook sits above the fog deck most days making for spectacular sunsets and less than spectacular dark and foggy hikes back to your car.

Sunset from Samish Overlook, with fog and San Juan Islands in the background.

A colorful winter sunset from Samish Overlook, nearly 1300 feet directly above Chuckanut Drive. The tops of a few of the San Juan Islands are visible protruding above the fog.

The last nine miles of the route angle away from the mountains and coast and traverse the flat lands and fields of the Skagit River Valley. But just a few miles west of the Drive, along Bayview-Edison Road, you’ll find the Padilla Bay National Estuarine Reserve, which operates an excellent interpretive center with exhibits about the coastal ecosystems of the Puget Sound area and a small aquarium. This is also a great place to spot a number of the bald eagles that visit the Skagit River Valley and surrounding area each winter to feast upon dying salmon. Padilla Bay (actually an estuary) is so shallow that at low tide, mudflats extend for hundreds of yards away from the coast.

A bald eagle sits in a tree at the Padilla Bay National Estaurine Reserve

Spring brings large quantities of nesting Bald Eagles to the Skagit River Valley. We saw four eagles within five minutes of exiting the car at the Padilla Bay Interpretive Center.

Ripples in the sand catch the last light of Sunset at Padilla Bay

Ripples in the muck reflect a cold, windy, and colorful  sunset out on the mudflats at Padilla Bay.

Eventually, Chuckanut Drive meets up with I-5 in Burlington, just a few miles north of the infamous I-5 bridge that collapsed into the Skagit River last year. From here it’s a quick 15-20 minutes drive back to Bellingham along the interstate. Or if you feel like braving that bridge, I hear there are a few good breweries in Mt. Vernon….


Honeycomb Weathering from the Desert to the Sea

Continuing on with our recent geological theme here at Pyroclastic Pixels (you’d almost think I was a geology grad student or something…), today we are going to take a look at one of the most picturesque geological curiosities you’ll ever find: honeycomb weathering, also frequently referred to as “tafoni”.  Those two terms aren’t really exactly quite completely equivalent but we’re not going to journey down the nit-picky fork in the road today.  Honeycomb weathering is pretty cool. About the only thing that would make it better is if the holes were actually filled with honey. That joke sounded way better in my head than it looks on the screen.

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Honeycomb weathering in sandstone at Teddy Bear Cove, Chuckanut Bay, WA (all pictures are from this locality unless otherwise noted)

Specific geographic and geologic conditions are needed for honeycomb weathering to develop, yet these conditions can be satisfied in a variety of places, from the arid deserts of the American Southwest, to the storm-battered shores of the Pacific Ocean. Here in northwestern Washington State, honeycomb weathering occurs along the coast, along and just above the high tide mark, in areas where a rock unit known as the Chuckanut Formation is present.  The pictures on this page were taken at Teddy Bear Cove, just south of Bellingham, WA, which has some of the most spectacular examples I’ve ever seen. The Chuckanut Formation, or “the Nut” as I like to call it when I’m feeling lazy, is a thick series of sandstones, conglomerates, and occasional coal seams that were deposited about 60 million years ago when NW Washington occupied a large basin at the foot of an ancient mountain range that occupied more or less the same space that the Modern Cascades now occupy.

There is a good reason that sandstone is one of the rock types most susceptible to this type of weathering. Sandstone is essentially composed of countless tiny, sand-sized particles of various minerals (mostly quartz and feldspar in the case of “the Nut”) which are held together by some sort of substance, known as cement, that “glues” them all together into a solid mass. In most sandstones, this substance is either calcium carbonate (CaCO3) or silica dioxide (SiO2), also known as quartz. Honeycomb weathering forms when salt-laden sea spray lands on the sandstone. As the salty sea water evaporates, tiny salt crystals form on the surface of the rock. The growth of these salt crystals on the surface of the rock physically separates the sand particles from the cement. Over time (a long time…), this creates a small depression in the rock. Once a small indentation forms, a positive feedback effect is created; the hole has a greater surface area than a flat surface and thus more rock is exposed to incoming sea spray. Sand grains are thus separated from the cement at a faster rate, thereby enlarging the hole. In some locations, you can actually see little piles of sand grains in the cavities, grains that were once part of the rock but have now been forcibly removed by the salt. I’ve found that this is most prevalent in areas just above the high tide line where wave action can’t wash the sand grains back out to sea.

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But Zach, you say…how then does honeycomb weathering form in places like the desert Southwest where the closest thing to sea spray you’re going to find is mule deer pee?  Ah…well I’m glad you asked. We often observe honeycomb weathering in sandstone in places such as Southern Utah that are far away from the sea. I had some difficulty finding a halfway decent picture of desert honeycomb weathering from my archives, but I was able to find one that I took in 2008 in Capitol Reef National Park (see below). If you want to see a lot better examples, just do a Google image search for “Utah tafoni”. While the exact cause may vary, and the individual pits tend to be larger, the process involved is essentially the same. We still need to find some way to separate our sand grains from the cement. Many washes in the southwest are dry for most of the year but are very rich in dissolved salts when they do flood. In desert environments, it’s no surprise then that we tend to find honeycomb weathering predominantly along dry stream beds and canyons. When a flood comes through, even though the water may not be as saline as the ocean, it is still salty enough to form small salt crystals when it evaporates, which it invariably does. In other locations, slightly acidic groundwater percolating through rocks can actually chemically dissolve calcium carbonate cement, leaving the sand grains with nothing to cling to.

Larger scale cavernous weathering features in Capitol Reef National Park, Utah

Larger scale cavernous weathering features in Capitol Reef National Park, Utah

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Hard as it might be for you to believe, this has been only a cursory explanation of the honeycomb weathering formation process. If your brain hasn’t begun to resemble honeycomb weathering by now and you are interested in the gritty details (perhaps you arrived here in the process of researching a paper or maybe you’re a geology nerd like me and just like knowing about such things), an excellent academic paper on the formation of honeycomb weathering can be found here.  Regardless, your next step should be to pull out a geologic map, find the closest beach with some sandstone, pull your boots on and go find yourself some honeycomb weathering! Or you could always just look at the rest of these pictures I suppose…

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Back to the Northwest: the Land of Homework and Geology

Yes, I am still alive. Although I imagine that someone who wasn’t would have marginally more time to attend to a photo blog than I have over the past few months.  Between a full class schedule, 15 or more hours of work a week, writing a thesis, and occasionally taking time to interact with other human beings in a social setting leaves sadly little time for photo editing and blogging.  But now that the annual bundle of happiness that is the four days off from school offered by Columbus Day weekend is here, I find myself with free time (gasp!) and no shortage of photos to sift through from the past several months.

My most recent excursion was the 4-day whirlwind of turtle tops, rock hammers, marshmallow volcanoes, humorous jokes, campfires, burritos, and all-around general merriment that is our bi-annual Regional Geology field trip.  This year we made a circuit through central Oregon to look at the ancient Cascade volcanoes and some of the best preserved fossil beds in the world. Rather then bore you with my umpteen pictures of rock outcrops with my lens cap or pencil in them for scale, I’ll share the ones that show why trips like these are the biggest perk of being a geology student:

Smith Rock State Park, Oregon: a rock climbers paradise and caldera of an ancient supervolcano.

Preserved ancient soils in the Painted Hills, John Day Fossil Beds National Monument

Mescall Overlook, John Day Valley, OR

Dogs in Oregon apparently like chasing flying moustaches...who knew?!

Thick lava flows beneath the US 97 Bridge over the Crooked River, near Bend, OR

My big fossil find of the weekend: ammonites native to Asia plastered onto North America via plate tectonics!

Community Hall in Izee, OR

P.S.  For those of you stumped by the marshmallow volcano reference, watch this to see what to see a geology department tradition and learn what happens when you stuff several bags of marshmallows inside an empty beer can.  Yes, this is how geologists entertain themselves.

 


HOLY CRAP ORION IS UPSIDE DOWN! and other New Zealand stories

So about an hour ago, I was hanging up my laundry to dry outside on my balcony when I happened to notice that there was a star visible in the small slice of sky visible between my roof and the apartment building next door.  This was significant because it marked the first time since arriving in New Zealand that the sky wasn’t 100% overcast at night.  This was further significant because it means I got to see southern constellations for the first time!  The fact that this was definitely one of the highlights of my trip so far may only serve to further affirm my nerdyness but for an avid amateur astronomer and astronomy major, this was big news.  I grabbed my iTouch (upon which I had installed an app called SkyVoyager specifically in preparation for this moment) and rushed outside.  Now the sky was only about half clear and I am in the middle of a pretty good sized city but it was still cool to see stars that I had never seen before.  The Southern Cross, Alpha Centauri, Magellanic Clouds, etc…were all visible.  The Southern Cross was shockingly underwhelming to be quite honest. The Big Dipper could kick it’s you know what (we’ll keep the blog family friendly for now…) any day.

Anyways, enough Astro babble.  I just got back from a 5-day field trip for the geology field mapping class that I’m taking down here.  Disregarding the fact that there weren’t enough cabins at the campground for everyone (as we had been told there would be), the fact that the tent to which I was assigned had fist sized holes in it and leaked like a sieve, the fact that trying to make a geologic map in the rain/wind is rather difficult and unpleasant, and the fact that I still have absolutely no clue what I was eating for lunch every day, it was a great trip.  There were about 70 students in the class making it a far larger operation that any Whitman geo trip I’ve ever been on.  We we’re camped near a place called Maerewhenua (pronounced Mar-eh-feh-new-ah or something close to that….) and spent the better part of four days combing over 70 square kilometers of sheep farms and river valleys making a geologic map of the area all while laughing uproariously (inside at least) at how all of the Kiwi’s pronounce “basalt”.  It was a decently scenic area and great fun when it wasn’t windy and raining.  With the exception of the aforementioned lunches, the food was excellent.  The university hires a local woman to come cook for us all week and on the last night, we even got to eat fresh lamb that she had brought in from her own farm earlier in the day!  Plus I somehow managed to only shock myself once on the 8-billion or so electric fences we crossed so I consider the week a roaring success.

Now for some pictures!   Given that it was raining most of the time, I actually didn’t take many pictures…at least not nearly as many as I would normally take over a 5-day span.  The fact that there is sunshine in many of the pictures does not imply that sunshine was frequent, just that that’s when I actually got the camera out.

Typical view of the field area

Maerewhenua River flowing past the campground

The awesome sign we got to set up along the road wherever we went

Part of the class checking out a limestone quarry

Hedgehog chilling in a cow pie

Elephant Rocks. Apparently scenes from the Narnia movies are filmed here although I'm not sure which ones since I only ever saw the first movie and even that was a long time ago.

Castle set used in the Narnia movies

That’s all for now.  Classes start tomorrow morning…finally. Feels weird to have academic obligations again after a 2+ month break.  I’ll post more pics of the Dunedin area later this week.


A Day at Soldier Pass

Soldier Pass is one of my favorite areas in Sedona for hiking and photography.  It is close to town and doesn’t require taking my car on roads that make me feel like the axles are going to spontaneously detach from the car at any moment.  Plus, one can find enormous sinkholes, picturesque pools of waters, and a cluster of natural arches all within about 1.5 miles of one another.  Here’s a few pictures from a hiking and geocaching excursion to Soldiers Pass last weekend:

This is the final Arizona entry for awhile.  As of Thursday, I am off to Utah, Walla Walla, and then New Zealand for a study abroad semester. More to come on that soon…with pictures of course!

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