Vision Quest 2016: Bones of the Living Earth
Thursday, June 9th, 2016: 2016 Trips, Mojave Desert, Nature, Regions, Road Trips, Rocks.
Two of the three reasons why I first fell in love with the desert had to do with rocks. One: I spent my early childhood in the foothills of the Appalachians, playing around cliffs and caves and outcrops, and I love that in the desert, the bones of the earth are exposed, dominating the landscape, instead of buried under forest and foliage. And two: the boulder piles I first encountered in the desert offered natural shelter.
My mountains, looking southeast. My land is in the center of the photo, which I took while commuting to the West Coast by air. Length of mountains from near left to far right is 25 miles.
Mountains Alive: Landscape, Weather & Orientation
Peaceful peoples around the world hold mountains sacred, unlike dominant societies that disfigure them with prominent castles, industrial mines, watch towers and antennas.
Mountains are part of the living skin of the earth, rising, tilting, eroding, shaking, or erupting. They shape climate and weather, channeling wind and forming clouds, storing their water and making it available for humans and wildlife, and providing habitat and shelter for level upon level of diverse ecosystems.
Those who live, work or play in mountains rely on their peaks, pinnacles and canyons as landmarks for orientation and wayfinding. This is even more true in the desert, where the lack of uniform forest cover makes unique landforms visible.
The mountains in the distance compressed this morning’s storm clouds, precipitating moisture, and their peaks, reaching into cold air, ensured the moisture would fall as snow
The high peaks of the Spring Range, the Mojave’s tallest mountains, captured snow from yesterday’s storm
A thunderhead dumps rain at the north end of my mountains
The thunderhead spreads southward across the range
Strong desert winds lift rock dust high into the atmosphere and move it across the landscape
This tiny volcanic cinder cone, one of the youngest geological features in the desert, provides a useful landmark for travelers, since it stands alone in a broad basin between mountains
Tiny pinnacles on the horizon four miles south of camp are such familiar landmarks that we’ve given them names
From much closer, we can see that Pyramid and Blockhead are granite monoliths hundreds of feet tall
In the desert, it’s easy to reach a long view over the landscape, and without forest cover, distant ridgelines have unique, easily readable signatures
Confused by turns in the canyon, I thought I was looking east, but when I climbed to this pass, the salt flats just visible over the farthest ridge proved that I was facing south
Some terrain is a real challenge to read; this view is crossed by five side canyons, superimposed from front to back
Reaching a pass on a ridgeline can be a dramatic moment, offering your first view into unexplored territory
Even from many miles away, I can spot a half dozen familiar landmarks in this view of the south end of my mountains
This granitic range, probably the most rugged in the desert and completely devoid of trails like all our other mountains, presents just the kind of challenge we desert hikers crave
Joints, Contacts & Basins: Storing & Releasing Water
People talking about mountains and water often refer to the rock’s permeability or impermeability, but mountains rarely consist of a single solid mass of rock. Granite is a plutonic rock, formed as a great mass of molten material rises through the earth’s crust, cooling and crystallizing into bulbous shapes that continue to settle and deform as they cool, resulting in a three-dimensional network of internal fractures or joints.
Rainwater or snowmelt trickles into these fracture networks, which become storage reservoirs as they slowly fill with water. When the water encounters a solid, impermeable surface below it, it will look for a way out: a seep or spring.
Rain falling or snow melting on granite peaks seeps into a complex network of joints or fractures, where it can be stored for years.
This rare hollow in a granite outcrop, 1,500′ up on a ridgeline, holds 10 liters of water from last weekend’s rain, a precious bounty for wildlife – or passing humans
This mesquite thicket has colonized a horizontal contact with an impermeable layer, where water stored in the mountain is slowly forced out.
This pool, dammed by miners more than a hundred years ago, stores water seeping drop by drop from a tight contact zone between granitic and metamorphic rock
A group of hikers sits across the contact zone, above the seep and pool
Another seep in the bottom of a big canyon, where water stored in the rock drains slowly out of a fracture, depositing minerals the water had dissolved while in storage
Channeling Water: Erosion & Sediment
In granitic mountains, the shape taken by the cooling surface of the pluton provides the original framework for the landscape. Once the living rock is exposed to the air, wind, rain and snowmelt follow hollows and joints on the surface, polishing and eroding for eons, sculpting canyons and valleys, carrying sediment down and away from the mountains, spreading nutrients and creating habitat for diverse communities of life.
This basin high in the mountains is crossed by three major watercourses which merge in the middle to enter a steep canyon, out of sight at left, and drain down onto the bajada. The shape of the granite, cooling and crystallizing as it rose from deep in the earth, created the original framework, and rain has been eroding and further shaping it for millions of years.
Eons of storms, from one ice age to the next, have smoothed and polished the granite ledges of this normally dry waterfall
Furrows in the head of the pluton become canyons on the surface
Sand eroded and carried down from the basin high above spreads out from the mouth of the canyon
Rare flash floods drive sediment far from the mountains into big, forested arroyos that feed the distant Colorado River
Alluvial Fans & Basins
Sediment carried down the mountains by streams and floods is deposited outside, building up for eons to form alluvial fans which gradually bury the living mountains up to their shoulders, separating mountain range from mountain range by broad alluvial basins.
In the bottom of each basin, the alluvial fans of opposing ranges may meet in a big arroyo, or they may drain into a playa, a dry lake with no outlet, sometimes accompanied by a salt marsh and/or wind-formed sand dunes. Alternately flooding and drying out, dry lakes collect, concentrate, and expose mineral salts which become another valuable resource for humans and wildlife.
Desert mountains are buried to their shoulders in their own sediment, weathered off over millions of years and deposited in the form of alluvial fans which slant gently for miles into the bottom of a basin, where they may merge into a dry lake or a big arroyo. Sand and dust from alluvial fans and dry lakes can be moved much farther across the desert by windstorms.
At the upper end of the alluvial fan, and on terraces throughout the mountains, desert pavement may form over long periods as wind removes the fine dust between pebbles, cementing them into a natural mosaic
These sand dunes, blown upslope from the bottom of a long, troughlike basin, have been shaped by longitudinal winds into a pattern of transverse waves
Volcanic Rock
The southwestern Mojave is crossed by a belt of recent cinder cones and the extensive lava fields they produced. Volcanoes are both destroyers, in the short term, and creators, in the long term: creators of mountain habitat, and conduits elevating mineral nutrients to the surface from deep inside the earth.
The southwestern Mojave is crossed by a belt of recent cinder cones and the extensive lava fields they produced
Red volcanic outcrops at the head of the Black Canyon of the Colorado River provide ideal habitat for wild sheep
Plutonic Rock
We desert dwellers know that the best drinking water comes from granite.
My mountain range is known for its granite pinnacles which provide distinctive landmarks on the ridgetops
But at ground level, the gentle slopes and curves of plutonic rock provide shelter and a safe surface for both rest and play
Rare hollows in granite store water for people and wildlife
At sunset, this granitic landscape becomes a warmly glowing rock garden
Granite shows its molten origins in fanciful, sometimes anthropomorphic shapes
But most of the granite in my mountain range is ancient, burnt-looking, forming canyons worthy of Mordor
In a granite landscape, humans gravitate toward boulder piles that promise shelter
A big boulder pile is a labyrinth of light and shadow to explore
As my song says, “exfoliation, crevice invasion” – the pointed rock was knife-thin, having exfoliated from the mother rock long ago. Sometime later, water freezing and expanding in a crevice of the mother rock split off the chunk forming the dark wall at the left of this photo, and the pointed sliver slid down on top of it.
This black xenolith was absorbed by the molten pluton from the country rock it pushed up through
Our granite mountains take on the color of the setting sun
Metamorphic Rock
The north slope of our land is a nappe, a layer of the earth’s crust that has been folded upon itself, creating unimaginable pressure and heat that melted, compressed, and recrystallized the original layers of sedimentary rock
This metasedimentary outcrop is my favorite rock on the property
It includes thin, translucent, jade-green recrystallized layers
Sedimentary Rock
Striped Mountain, in the Mojave National Preserve, with its dramatically tilted layers of limestone
This rare white limestone outcrop hosts exotic endemic plants
A rare plant on the limestone
A small outcrop of bright red mudstone provides a color contrast for native flowers
I found this conglomerate in the bank of a dry wash while exploring a remote canyon
My botanist friend took me into a canyon lined with gabbro
These native flowers love the gabbro
This gabbro boulder in my mountains is decorated with lichen
Near the gabbro is this boulder of breccia, also festooned with lichen
Interface With Life
Biological soil crusts, which have been around much longer than humans, were one of my major discoveries on this trip.
Geologists call rock that is still anchored to the earth “living rock”. Biologists, defending what makes them special, say that rock is nonliving, and lichen is on the front line between the living, the biota, and the nonliving, the abiota. Lichen is a partnership between algae and fungi that breaks down and releases nutrients from the rock.
Biological soil crusts also work at the interface between living and nonliving. They are a complex structure formed in collaboration between algae and many other microscopic soil organisms.
According to the expert, this local soil crust in my mountains is a “green algal lichen crust in the Placidium/Clavicidium complex”. Soil crusts represent one of many ecological frontiers in the desert, just now attracting the attention of biologists.
Shelter
The interior of this boulder pile provided a spacious, weatherproof shelter that Katie and I improved and camped in for years
When Katie and I arrived unprepared one December to find the desert under 6″ of snow, we built a fire and stayed comfy in our rockshelter
This huge freestanding granite boulder, four times the height of a human, provided precious afternoon shade for a prehistoric Indian campsite
One of my honored elders, an artist, taught himself to paint the desert while living as a hermit for 7 years in this remote rock house
I enjoy the shade and shelter of a granite boulder, high on a windswept ridge
Tools & Signage
I repair gaps in the roof of our historic shade house, using metamorphic rocks to anchor sheet metal left by the old miners
Desert Indians made exquisite tools from stone
This obsidian, the ultimate tool rock, was traded for and carried from a source far away to the north
Granite boulders with “desert varnish” were used as public sign boards by Native Americans
Rock piles and caverns also provided hidden, intimate shelters for paintings and petroglyphs which communicated with the spirit world
Mining
Mining by dominant societies has been terribly destructive to both human communities and natural ecosystems, but ironically, my friends and I wouldn’t have been able to enjoy the desert for all these years if these mountains hadn’t been full of valuable minerals, and if we hadn’t had access to the roads built and long abandoned by miners and prospectors. I actually bought my land from an old prospector who just loved being out there and used prospecting as an excuse for camping in the mountains.
As likely applies to the other sciences, many if not most geologists work for private industry, prospecting for minerals to be exploited. Compartmentalization in science, as in the larger society, undercuts accountability, since a specialist has little or no knowledge of the larger system his work will impact.
An abandoned silver mine, 1,500′ up the side of our canyon
The shaft entrance
The mine shaft
Swimming pool of the rich and famous? No, a water tank for the steam-powered stamp mill installed farther down the slope to break up ore from the silver mine
This arrastra, far up a side canyon, was a primitive Old World device for grinding ore
The arrastra
Ruins of the cabin above the arrastra where the mine operator lived
Desert mountains are littered with pork and beans cans and sardine tins from the old mining days
This abandoned mill in what is now a ghost town along the railroad was built to process tungsten from a mine in our canyon
Giant salt mines operate full-time on the salt flats below our mountains
Landscape Engineering
The engineering of natural habitats for sole human use appears to be the critical error leading to the downfall of dominant societies across time and space, from ancient city-states in the jungles of Southeast Asia, to the modern United States. You can see examples of this all over the desert.
Giant, failed solar power plant, next to superhighway which is itself a failure, gridlocked on weekends
Lake Mead, a huge man-made reservoir which is shrinking and silting up
Tunnels built for railroad supplying construction of Hoover Dam, which created Lake Mead, now part of a public trail
Unsustainable suburban sprawl on the edge of Las Vegas
Your geological descriptions are perfect, Max, and your prose is sensitive to the nature around us and poetic in style. The wonderful pictures bring back great memories for me, particularly the boulder-rich outcrops. Boulders – they can be left by glaciers. Called erratics, they are all over New England where we now live. They can be formed by running water, such as in the alluvial fans you describe, moved only by occasional super floods, getting more rounded and smaller with each passage. But the ones on the mountain tops and ridges with unusual shapes at times, are the product of spheroidal weathering, first along joints with their dust debris cleanly spirited away over time by wind.