Archive for the ‘Geology’ Category

Washington’s Channeled Scablands   5 comments

A very calm dawn at Hutchinson Lake in eastern Washington's Columbia National Wildlife Refuge.

A very calm dawn at Hutchinson Lake in eastern Washington’s Columbia National Wildlife Refuge.

Several recent posts have highlighted eastern Washington, a region I visited the last week or so of May to scout and photograph.  While the Palouse in the southeast is quite famous as a landscape photography destination, I made a point to visit an area that is just as famous but with a different group of people altogether.  The Channeled Scablands cover a rather large region in central Washington with spectacular erosional features.  It’s unusual geography records the largest flood we know of in earth history.  For this reason the Scablands are on most geologists’ bucket lists.

In springtime, Drumheller Channels in eastern Washington is a paradise for wildlife because of the numerous wetlands formed in a normally dry area.

In springtime, Drumheller Channels in eastern Washington is a paradise for wildlife because of the numerous wetlands formed in a normally dry area.

GEOLOGIC SUMMARY

The Missoula Floods came racing down through this area towards the end of the last ice age.  The last one happened about 12,000 years ago, but there were dozens of similar deluges stretching back thousands of years before that.  The floods were triggered when an ice dam across the Clark Fork River in western Montana burst and the enormous Lake Missoula drained catastrophically.  The water cascaded down through what is now eastern Washington, down the Columbia River to what is now Oregon, and on to the coast.  Some of the larger floods equaled more than 10 times the annual flow of all the rivers in the world.

The Channeled Scablands in eastern Washington are a maze of canyons cut into thick columnar basalt lava rock.

The Channeled Scablands in eastern Washington are a maze of canyons cut into thick columnar basalt lava rock.

As you might expect with that much water, the evidence of its passing is still around.  Now it seems obvious of course, but it was not until a geologist named J. Harlan Bretz studied the area in detail in the early 20th century that the story was uncovered.  Initially, Bretz’s interpretation was rejected by the “titans” of the science of the time.  Sounds familiar doesn’t it?  Eventually one of the more powerful geologists of the day, Thomas Crowder Chamberlin, visited the scablands and came around to Bretz’s point of view.  It helped that the source lake, glacial Lake Missoula (which Bretz originally did not identify) was identified from ancient shorelines in Montana.

A quiet evening descends at Drumheller Channels in the Columbia National Wildlife Refuge in eastern Washington.

A quiet evening descends at Drumheller Channels in the Columbia National Wildlife Refuge in eastern Washington.

IF YOU VISIT

Over the whole length of the floods, across 4 states, there is abundant evidence that any visitor to the region can see.  In recent times the area has been receiving more attention of the tourist variety, but it is still very lightly traveled.  There is a great non-profit, called the Ice Age Floods Institute, who pushed congress to establish the Ice Age Floods National Geologic Trail in 2009.  The Institute runs great field trips, so if you’re planning to visit this region check out their website in the link above.  Most field trips run in spring and summer.

The Channeled Scablands in eastern Washington were carved by massive ice-age floods.

The Channeled Scablands in eastern Washington were carved by massive ice-age floods.

I visited a small portion of the scablands.  Traveling west from the Palouse I passed through Othello, visited the Drumheller Channels, and moved on to the Columbia River near Quincy.  The Potholes lies between these two.  With spring’s high water, I found superb wetlands and wildlife (especially birds) all through this area.  But Drumheller Channels was perhaps my favorite, because of its manageable scale and beautiful terrain.  It is part of the Columbia National Wildlife Refuge.

Despite the harsh name, Washington's Channeled Scablands are full of wetlands and beautiful at sunset.

Despite the harsh name, Washington’s Channeled Scablands are full of wetlands and beautiful at sunset.

GEOLOGIC FEATURES

      • Coulees.  The most obvious terrain feature through the scablands is the coulee.  The word comes from the French (to flow) and describes any drainage that is intermittently dry and wet.  In the Channeled Scablands the coulees take on a variety of sizes, and were all carved by the Missoula Floods.  Because the bedrock here is all Columbia River Basalt (a very hard lava rock formed 17 million years ago), the coulees are typically steep-sided.  Grand Coulee (site of the large dam), Frenchman’s Coulee, and Moses Coulee are among the largest.
Columnar basalt is found throughout eastern Washington.

Columnar basalt is found throughout eastern Washington.

      • Giant Ripples.  Amazing features that are much rarer than coulees but also testify to the catastrophe are giant current ripples.  When you walk along a tidal flat or beach area, you often encounter those small ridges in the mud or sand.  They are only an inch or two high.  Giant current ripples were formed in a like manner (water currents) but on a huge scale.  They can reach 20 meters (66 feet) high!  They occur near the town of Quincy on the west bank of the Columbia River, across from the resort of Crescent Bar (see image).
Giant current ripples formed during the ice-age Missoula Floods are found along the Columbia River in eastern Washington.

Giant current ripples formed during the ice-age Missoula Floods are found along the Columbia River in eastern Washington.

Potholes & Erratics.  Another type of flood feature to look out for are the abundant pothole lakes and ponds.  These depression, now havens for migrating birds and other wildlife, were either scoured out by the floods or formed when giant icebergs (torn from the ice dam and floated down by the floodwaters) grounded and then melted, leaving a depression.  Large rocks carried within these icebergs, rocks like granite that occur in the Rockies but nowhere near this area, were simply dropped on the landscape when the floods receded.  Now they stick out like a sore thumb, in fields and along gentle hillsides.  They are called glacial erratics.  You’ll see them along the Frenchman Hills road just west of Potholes Reservoir, among other places.

A glacial erratic dropped from an iceberg rafted down by a giant ice-age flood sits incongruously in a central Washington farm field.

A glacial erratic dropped from an iceberg rafted down by a giant ice-age flood sits incongruously in a central Washington farm field.

      • Steptoes.  Underlying part of the Palouse is terrain similar to the Scablands.  The floods formed three main channels, and the eastern-most carved into the Palouse, eroding away much of the rich soil.  Fortunately for us, the floods were no bigger than they were.  Otherwise all of the rich loess soils of the Palouse would have been carried away.  Underlying all of this are the lava floods of the Columbia River Basalts, one of the world’s great lava provinces.  But poking up in a few places (particularly in the Palouse) are small islands of older rock.

Both Kamiak and Steptoe Buttes in the Palouse are made of seafloor sedimentary rock that is much older than the surrounding sea of basalt.  A bit of geo-trivia: a steptoe is the name that geologists use for this formation, where older rock pokes up island-like through younger rocks.  The name comes from the town and butte of the same name in eastern Washington’s Palouse.  Palouse Falls, described in a previous post, is a great place to get a feel for the power and scale of the floods.

The Potholes area in eastern Washington's Channeled Scablands is filled with wildlife-rich wetlands in springtime.

The Potholes area in eastern Washington’s Channeled Scablands is filled with wildlife-rich wetlands in springtime.

I know I will return to the Channeled Scablands for further exploration, and you should do the same if you’re ever passing through the area.  If you’re interested in any of these images simply click on them to go to the high-resolution versions.  Then click “add this image to cart” to get price information (it will not be added to your cart until you make a choice).  Being copyrighted, the images are not available for free download, sorry.  Please contact me with any questions.  Thanks for reading.

The Upper Columbia River in eastern Washington is full of water during spring's heavy snow-melt in the Rockies where the big river originates.

The Upper Columbia River in eastern Washington is full of water during spring’s heavy snow-melt in the Rockies where the big river originates.

The Palouse III – Loess & Farming   1 comment

The classic view of the Palouse from atop Steptoe Butte in eastern Washington.

The classic view of the Palouse from atop Steptoe Butte in eastern Washington.

I just returned from a trip to southeastern Washington.  The Palouse region north of the Snake River and stretching along the Idaho border was my prime destination.  Among landscape photographers, the Palouse is justifiably famous for its unique landscape of rolling, wave-like fields of wheat.  It is a very rich farming region, primarily known for its dryland wheat.  But it’s also one of the world’s premier lentil-growing regions.

As is the case for most of our planet’s resources, where and how we take advantage of the bounty is dictated by geology and geography.  This is especially true of farming.  The Palouse bears a lot of resemblance to other rich farming regions in the world in at least two respects: it is relatively flat and it’s covered in a special kind of silt called loess.  You can pronounce loess anyway you want.  But perhaps Lois is best reserved for some women by that name.  Most people in the know pronounce it somewhere between loose and lus, sort of luhs.  Brits put an r in there right before the s.

Some of the terrain in the Palouse of eastern Washington is left golden-bare even in late spring when most everything is vibrant green.

Some of the terrain in the Palouse of eastern Washington is left golden-bare even in late spring when most everything is vibrant green.

Loess is a windblown silt found in many places throughout the world.  It is made of angular pieces of rocks and minerals somewhat finer than sand.  It forms such rich soils because the minerals in it are diverse.  This is not always the case with fine debris deposited on the earth’s surface, but loess is special.

It is a gift of the Ice Ages.  All over the world, when glaciers retreated (both after the last time 10,000 years ago and during previous retreats), the fine debris scoured from the various rocks that the ice passed over was left bare.  Winds picked up this silt and sand and deposited it downwind, often far downwind.  Natural depressions, the base of mountains, or anywhere that wind speed drops, were natural places for loess to be deposited.

In springtime, wildflowers bloom on Kamiak Butte in the Palouse.

In springtime, wildflowers bloom on Kamiak Butte in the Palouse.

In the case of the Palouse, loess from the Ringold Formation and from glacial deposits exposed to the west and south was blown in and deposited essentially in dunes.  This is a big reason for the wave-like nature of the landscape.  It accumulated during the drier and windier climates between glacial advances, and did so for over a million years.  The loess in the Palouse reaches up to 200 feet thick in places.

Two little extra features of the loess deposits found in the Palouse help to make it such a rich dryland farming region.  For one, the Cascade volcanoes to the west occasionally supplied layers of ash into the mix.  This ash not only adds to the mineralogical diversity (and thus the richness of the resulting soil) but is also very good at holding water.  The Palouse soils are famous for their ability to hold onto the modest amount of water they receive.

The wheatfields of the Palouse in eastern Washington on the north side of Kamiak Butte.

The wheatfields of the Palouse in eastern Washington on the north side of Kamiak Butte.

The second feature is another happy coincidence.  The topmost loess deposits, blown in after the last glaciers retreated 10,000 years ago, also happen to be among the most diverse minerals-wise.  So they support the richest soils.  Mount Mazama in Oregon (now Crater Lake) blew its top 6700 years ago and its ash is prominently represented in these latest Palouse loess deposits.

So farmers have it good in the Palouse, growing their crops on a landscape covered in especially rich soils that hold water well.  There is one little problem though: these latest loess deposits are also the most prone to loss through erosion and poor management.  Just like so many agricultural areas in the world, this one requires careful management practices to conserve the precious soil.

Wind turbines are situated along the crest of a ridge in the Palouse, Washington.

Wind turbines are situated along the crest of a ridge in the Palouse, Washington.

The geologic story does not end here though.  The loess deposited in long wave-like dunes originally extended far to the west of where you find it today.  If you head west from the Palouse you run right out of rich dryland wheat country and into a different terrain altogether.  This is the so-called channeled scablands, spectacular result of the great Missoula Floods of the last Ice Age.  I will cover this great story in a coming post; suffice it to say these floods removed much of the region’s rich loess before human farmers ever got the chance to farm it.

A group of mergansers rides the Palouse River downstream near the town of the same name in Washington state.

A group of mergansers rides the Palouse River downstream near the town of the same name in Washington state.

People have been farming here since the late 1800s.  In the 1880s there was a land-boom after dryland wheat farming was proved valid in the previously settled Walla Walla area to the south.  In fact, the last decades of the 19th century saw far more people living here than lived in the Puget Sound region to the west.  Now of course it’s the opposite.  The Palouse is sparsely populated while the Puget Sound has Seattle, Microsoft and traffic nightmares.  There are signs of new growth here, as some people tire of the rat race and move here, expanding the suburbs of large towns like Pullman, Washington and Moscow, Idaho into prime agricultural lands.

The empty Palouse of eastern Washington at sunrise is all wheatfields and sky.

The empty Palouse of eastern Washington at sunrise is all wheatfields and sky.

But for now the Palouse remains a quiet, peaceful place where open spaces are the rule.  Stand atop Steptoe or Kamiak Butte and look out on the endless waves, bright green in early summer and golden brown in autumn.  You’ll only see scattered farmhouses, a few barns, a few two-lane roads with little traffic.  It’s a gorgeous setting, especially at sunset when the shadows are long, bringing out the unique textures and look of the place.  I will surely be coming back.

Thanks for reading.  Stay tuned for more on eastern Washington in the next post.  Hope you enjoy the images.  Please be aware they are copyrighted and not available to download for free without my permission.  Please contact me if you have any questions.  If interested in one of the images, just click it to get purchase options.  Thanks for reading!

A solitary clump of blooming lupine decorates a piece of bunchgrass prairie in the Palouse, Washington.

A solitary clump of blooming lupine decorates a piece of bunchgrass prairie in the Palouse, Washington.

Mount St Helens – Early Season   4 comments

The Hummocks near Mount St. Helens is an area filled with remnant debris from the devastating eruption of 1980.

The Hummocks near Mount St. Helens is an area filled with remnant debris from the devastating eruption of 1980.

I visited the north side of Mount St. Helens yesterday with my uncle and my dog.  St. Helens is a sleeping volcano, by far the most active in the Cascade Range.  It erupted with extreme violence on May 18th, 1980, killing 57 people.  Now it is a National Monument managed by the U.S. Forest Service, and is in full-on recovery mode.

Since the monument is only partially open now, the snow just having recently melted off the highway, we had it to ourselves.  And what a gorgeous day to be there with only a few other lucky souls!  The mountain was glittering with rapidly melting snow, the water was pouring down through creeks and over waterfalls, and the birds and amphibians were busy with their lives on the shores of full lakes and ponds.

Beautiful Coldwater Lake at Mount St. Helens in Washington state.

Beautiful Coldwater Lake at Mount St. Helens in Washington state.

GEOLOGY

This whole area was transformed by the eruption of St Helens in 1980.  The volcano awoke on March 16th of that year with a series of small earthquakes.  A week and a half later the mountain erupted, blasting a small crater out of the snow-covered summit.  The mountain then proceeded to work up to its big blast 8 weeks later.  The north flank of the mountain slowly bulged outward as magma moved upward.

Finally, on that beautiful Sunday morning, while folks were in church or tending their gardens, the bulge gave way and history’s largest recorded landslide occurred.  The volcano was essentially uncorked, and as the massive debris avalanche slid toward Spirit Lake (where Harry Truman – the old character who refused to evacuate his lakeside cabin – awaited his fate), the mountain erupted in a powerful lateral blast.  It had the force of 24 megatons, 1600 times the energy released by the atomic bomb dropped on Hiroshima, Japan.  Whole forests were mowed down and the mountain’s height reduced by 1300 feet.

The mass of rock, mud and ash cascaded down the North Fork Toutle River valley, burying the river and damming Coldwater Creek.  These types of debris avalanches typically form mounds (hummocks) where the debris comes to rest, and this is what happened here.  Erosion by streams further sculpts the landscape.  Actually, this strange hummocky terrain, which occurs in places worldwide, was a bit of a puzzle to geologists before St. Helens showed geologists how it is formed.  Beautiful Coldwater Lake, along with the adjacent hummocks and melt-water ponds with their unique ecosystem, owe their existence to the 1980 landslide and eruption.  Volcanoes destroy, but they also create.

Coldwater Creek at Mount St. Helens near its confluence with the Toutle River.

Coldwater Creek at Mount St. Helens near its confluence with the Toutle River.

We hiked partway around Coldwater Lake.  We had planned to make the 12-mile loop around this rather large lake, which was created when the debris avalanche from the 1980 eruption dammed Coldwater Creek.  But a wide, tumbling creek stopped us.  I hopped across, getting my feet wet.  Seeing my uncle hesitate, I built a very rough bridge out of logs for him to cross.  But at age 73, he has gotten very cautious.  He just doesn’t like doing anything even remotely hazardous.  And stream crossings are something he REALLY does not like on a hike.  So we turned back.

The beautiful Coldwater Lake near Mount St. Helens was formerly covered with huge trees before the devastating eruption of 1980.

The beautiful Coldwater Lake near Mount St. Helens was formerly covered with huge trees before the devastating eruption of 1980.

I was pretty disappointed.  The hike around the lake was promising to be one spectacular trek.  I’ll just have to get back up there soon to do the whole thing.  But I snapped quickly out of my funk when we found a great alternative just across the road from the lake.

Trees are reflected in one of the many ponds at Mount St. Helens' Hummocks area in Washington.

Trees are reflected in one of the many ponds at Mount St. Helens’ Hummocks area in Washington.

The Hummocks Trail is a very interesting 2.5-mile loop through strange mounds created by the 1980 debris avalanche.  At this time of year there are beautifully full ponds trapped between the hummocks, alive with frogs, toads and salamanders.  The trail also passes a couple fantastic viewpoints up the Toutle River to the hulking volcano, with its horseshoe-shaped crater and (often steaming) lava dome.  Interpretive signs along the trail teach about the eruption and formation of the hummocks.

Algae combined with bubbling oxygen from a meltwater pond at Mount St. Helens forms fascinating patterns.

Algae combined with bubbling oxygen from a meltwater pond at Mount St. Helens forms fascinating patterns.

After a late picnic at Coldwater Lake, where we did some birdwatching and general lazing about, I headed back up the Hummocks Trail to one of the ponds for sunset pictures.  We made a full day of it after all, and didn’t get back to Portland until near 11 p.m.  It had been a couple years since I had been up to St. Helens, and I am determined to not let that much time go by again.  It is just too nearby, too special and beautiful a place to neglect.

The rapidly melting foothills near Mount St. Helens in Washington are reflected in meltwater ponds.

The rapidly melting foothills near Mount St. Helens in Washington are reflected in meltwater ponds.

To get there, travel north on I5 from Portland, Oregon (or south from Seattle).  Get off the freeway at the exit for Castle Rock and travel east on Highway 504 about 45 miles to Coldwater Lake.  During the summer season, this highway is open all the way to it’s end at Johnston Ridge Observatory, 7 miles on from the lake.  Find the trail around the lake either from the boat ramp or the Science & Learning Center up on the hill above the lake.  The Hummocks Trail is directly across Hwy. 504 from the turnoff for Coldwater Lake.  This part of Mount St. Helens is open from about late April until the snow flies in November.  Johnston Ridge is open from mid-May until late October.  There is an $8 fee to use Coldwater Lake or Johnston Ridge Observatories during the summer season.

Sundown at Mount St. Helens from the beautiful Hummocks area.

Sundown at Mount St. Helens from the beautiful Hummocks area.

Awash in Waterfalls   9 comments

A little-known waterfall in Oregon's Columbia River Gorge requires much effort to reach, being set in a pristine and beautiful alcove not accessible by trail.

A little-known waterfall in Oregon’s Columbia River Gorge requires much effort to reach, being set in a pristine and beautiful alcove not accessible by trail.

The waterfalls of the Pacific Northwest are both abundant and beautiful.  When I travel to other places in the world, and hear of a waterfall to check out, I always try to dial back my expectations so I’m not disappointed.  We are so spoiled around here.  Of course when we’re talking Angel or Victoria Falls, or even those in Yosemite closer to home, that’s different.  Those waterfalls are world-renowned for good reason.

Victoria Falls, which sits on the Zambia-Zimbabwe border, is one of the world's great cascades.

Victoria Falls, which sits on the Zambia-Zimbabwe border, is one of the world’s great cascades.

Waterfalls of the Gorge – Formation & Geology

The Columbia River Gorge, which slices through the Cascade Range of the Pacific Northwest along the border between Oregon and Washington, has an abundance of waterfalls.  In fact the Cascades were named for all these cascades along the length of the volcanic chain.  Most of the waterfalls in the Gorge are located on the Oregon side of the Columbia River.  This is because the south side of the river faces north, and so is kept cooler and much wetter than the drier, south-facing Washington side.

Most Oregon waterfalls drop over basalt cliffs, such as Toketee on the North Umpqua River.  This is not surprising, since basalt is a very hard rock, prone to forming cliffs resistant to erosion.

Most Oregon waterfalls drop over volcanic basalt, such as Toketee on the North Umpqua River. This is not surprising, since basalt is a very hard rock, prone to forming cliffs resistant to erosion.

Why are there so many waterfalls here?  Well to start with the climate is wet.  The Columbia’s active and ancient down-cutting, combined with the fact that rocks on either side are very hard volcanic basalt, means that the smaller tributary valleys are left perched above the level of the Columbia.  The Missoula Floods, which were the biggest in world history as far as we know, raced through here more than 10,000 years ago.  These deluges scoured and further deepened the Gorge, helping to sculpt the steep sides down which the waterfalls tumble.

This geological setting has given us easy access to the waterfalls, a fact best illustrated by Multnomah Falls, which can be seen from Interstate 84.  Multnomah is Oregon’s highest cascade at 620 feet (189 meters) total, in two tiers.  Multnomah Creek is busy eroding the basalt of course, but its progress is much slower than the Columbia’s (which is also much older).  And so the cliff that the waterfall drops over stands very near to the creek’s mouth.  Realize that waterfalls erode their cliffs such that over time they move backward, upstream.

Multnomah Falls is Oregon's highest waterfall and one of its most popular tourist attractions.  Here it is in full flood.  The bridge crosses just above the lower cascade and a trail continues to the top of the tall upper cascade.

Multnomah Falls is Oregon’s highest waterfall and one of its most popular tourist attractions. Here it is in full flood. The bridge crosses just above the lower cascade and a trail continues to the top of the tall upper cascade.

There are some larger streams in the Columbia Gorge, such as Eagle Creek, that do not tumble over a tall cliff near their confluence with the Columbia River.  These streams are eroding softer formations, often following fractures or faults that make their jobs even easier.  They are larger streams because of this easier erosion, not the other way around.  Softer rock formations equals larger drainage basins and thus more water captured by the stream.

These side-gorges are not lacking waterfalls however, far from it.  One simply needs to hike up them to get to the cascades.  Your hike will have the added benefit of leaving behind the traffic noiset from he busy interstate.  You will generally be hiking through a narrow and lush gorge.  Eagle Creek, in fact, is one of the most stunning hikes of this type to be found in the world.

A small but beautiful waterfall called Faery Falls in Oregon's Columbia River Gorge.

A small but beautiful waterfall called Faery Falls in Oregon’s Columbia River Gorge.

Off-the-Beaten-Track Waterfalls

Now on to this past weekend’s waterfall adventures.  I was on a mission not to visit and photograph those waterfalls with easy access, nor even those along one of the many trails in the Gorge.  My goal was to find at least one new waterfall, at least new for me.  Since I’ve hiked all through this area, that meant going off-trail.  With the recent wet weather, and also the new spring growth, I was in for some wet and messy travel through thick, slippery and potentially nasty brush and down logs.

The first hike was up McCord Creek to see if I could find some small cascades above beautiful Elowah Falls.  The going was pretty rough, and I decided to turn around in order to have the opportunity to visit both Upper McCord Creek Falls and Elowah Falls.  The two are actually so close together you can consider them to be two tiers of a single waterfall.  I could not get a unique angle on Upper McCord Creek Falls, so I”m not posting a picture of this one.  For Elowah, which is accessible by a trail, I wanted to get a good angle from near mid-point of the stream below the tall (220 feet) cascade.  It was raining and the flow was very high.  I got blasted with water from the falls when I passed it on the trail.  Then I clambored out onto a log to reach a mid-stream rock.  I set up there, but had a lot of trouble keeping my lens dry.  The resulting haze gives the picture a bit of a dreamy look, I think.  I will return to this spot when it’s not raining.

Elowah Falls in Oregon's Columbia River Gorge drops into a lush alcove filled with mossy boulders.

Elowah Falls in Oregon’s Columbia River Gorge drops into a lush alcove filled with mossy boulders.

The second hike was up Moffett Creek, which enters just east of McCord.  Moffett Creek is a fun one to hike up, primarily because there is no trail.  This is best done in late summer when flows are low enough to wade up the creek where necessary.  This time of year is a different story.  I tried hiking up the creek to reach nearby Wahe Falls (also known as Moffett Crk. Falls).  But it quickly became obvious that the stream (which requires constant crossing) was flowing with too much power to negotiate the route safely.  I turned around and hiked up onto the side of the valley, following the Munra Point Trail.  I soon left the trail and started traversing up the side of the valley, aiming for where I thought the falls were.  It was steep, slippery and very tough going.

A forest of cedars surrounds the waterfall on Moffett Creek in Oregon's Columbia River Gorge.

A forest of cedars surrounds Wahe Falls on Moffett Creek in Oregon’s Columbia River Gorge.

I was about to give up when I glimpsed the falls through the trees.  That gave me hope and I gutted out the last steep, thick section.  It’s an 80-foot single drop waterfall, seen by very few people (especially during spring flood).  There is a beautiful cedar tree near its base.  As per usual, it started raining steadily as I set up.  But I managed to get a couple good shots before calling it good.  It was near dark by the time I got out of there, soaking wet and muddy, but with a nice feeling of accomplishment.  There are more cascades further up Moffett Creek.  But that requires climbing gear, a partner or two, and lower water flows.  This is very rugged country.

Hope you enjoyed this illustrated primer on waterfalls.  I will post more waterfall photos on an irregular basis.  Just click on the pictures if you’re interested in prints or download rights.  You will need to click “add image to cart” and then make your choices.  Don’t worry, they won’t be added to your cart until you decide what you want.  The images are copyrighted and illegal to download for free, sorry.  Thanks for your interest, and thanks for reading!

Not a waterfall, but I needed a sunset shot to end this.  Crown Point and the Columbia River Gorge

Not a waterfall, but I needed a sunset shot to end this post! Crown Point and the Columbia River Gorge.

Larch Mountain, Oregon   8 comments

The full moon rises over Larch Mountain at the western end of the Columbia River Gorge in Oregon.

The full moon rises over Larch Mountain at the western end of the Columbia River Gorge in Oregon.

I’m taking a quick breather from the heavy science stuff  to highlight one of my favorite features of the area around Portland, Oregon, where I live:  the amazing extinct volcanoes.  There are at least 32 in the Portland metro area.  Oh right, well maybe this will involve a little bit of geology, which is science I suppose.  Sorry ’bout that.

The volcanoes, which were active up until about 300,000 years ago, are cinder cones and generally small shield volcanoes (like in Hawaii, except those are BIG shield volcanoes).  Many lie within the city limits, and several have city parks covering their summits.  I happen to live quite close to two of them: Rocky Butte and Mount Tabor.  Both have parks, but the one at Mt Tabor is much more extensive, with hiking trails, tennis courts, a large playground, picnic areas and more.  There is even a natural amphitheater at Tabor where live music is often hosted on warm summer evenings.  This popular venue occupies the volcano’s old explosion crater.  How cool is that?

The Columbia River flows west below the foggy forests of the Larch Mountain, Oregon.

The Columbia River flows west below the foggy forests of Larch Mountain, Oregon.

While each of these old volcanoes in Portland have their own character and personality, one stands out above the rest.  It is the king of them all, a looming hulk over 4000 feet (1240 meters) high on the east Portland skyline.  I’m speaking of Larch Mountain.  There are no larches on this well-forested shield volcano, so one might wonder how it got its name.  Early lumbermen sold noble fir from the mountain and labeled them “larch”.  How come misnomers so often stick?

Larch is quite a large mountain, but most people do not take notice of it at all.  Beyond Larch Mountain lies the Cascade Range, with big snow-capped peaks like Hood and Adams.  These more dramatic peaks draw the eye away from foreground mountains like Larch in Oregon and Silver Star in Washington.  But try to ride your bicycle up Larch’s 16-mile long road, and you quickly discover how big this mountain actually is.  Like most shield volcanoes (named for their resemblance to a shield laid concave side down), Larch can easily escape notice.  This is because they are so broad, with gentle slopes.  And the gentle slope is because most of what pours out of a shield volcano during eruptive phases is a very liquid form of lava – basalt.  Basalt is the hottest and most dense lava on Earth, and it covers most of the ocean floor.  Because of its relatively low silica content, basalt flows very easily, forming smooth shallow slopes and a broad volcanic edifice.

The view to the east from Larch Mountain's summit is dominated by Mount Hood and its cloak of forest.

The view to the east from Larch Mountain’s summit is dominated by Mount Hood and its cloak of forest.

Copious quantities of basalt flowed out of Larch Mountain’s summit vent during the early ice ages.  It’s part of what geologists call the Boring lava field.  The name does not describe geologists’ feelings about this very interesting volcanic feature.  Rather the name comes from the little town of Boring, which is southeast of Portland.  The volcanoes are actually quite interesting because of their position far to the west of the main axis of volcanism represented by the Cascade Range.

Whenever my eyes drift up toward the east, I’m always impressed by the sheer bulk of Larch Mountain.  In certain light conditions it is almost lost, but in other light you can get an accurate feel for how dominant the mountain really is.  The views from the top are absolutely stunning.  You can look east to see an interesting angle on Mt Hood, north to see Mounts Rainier, St Helens and Adams in Washington, or west down the length of the Columbia River.  I often ride my motorcycle up there for sunset when the road is open (snow closes it in winter).  And stargazing from the summit is quite excellent, despite the proximity of Portland’s light pollution.

If you ever find yourself in Portland and want to catch the sunset from a high viewpoint, make the drive up to Larch Mountain.  Just head out the Historic Columbia Highway from Troutdale.  Not far past Corbett, and just before you come to Crown Point, you will see a sign where the road angles up to the right.  Don’t forget your camera!

Larch Mountain dominates the view from the wetlands of Portland's Smith and Bybee Lakes.

Larch Mountain dominates the view from the wetlands of Portland’s Smith and Bybee Lakes.

Life in the Universe III   13 comments

Isn't it natural to believe that our Creator is from on high?

Isn’t it natural to believe that our Creator is from on high?

At one time I thought God created everything, but I can’t remember ever truly believing it was during 6 very busy days.  I do remember giving serious consideration to whether or not Purgatory would be an interesting place to stop before going to Heaven, even if there was a small chance I could be sent instead to Hell by mistake.  Then soon after I seriously began studying science, I put my inner religious beliefs into a little box and went on, unencumbered, to feed my curiosity.  I didn’t throw my beliefs away.  I believe that as you go through life, you should try not to throw things away unless you really need to.  We already lose too much as we grow older.

Buddhists create a spiritual atmosphere with these: Laos.

Buddhists create a spiritual atmosphere with these: Laos.

I learned that it’s likely life emerged from non-life by a trick of chemistry, and that was that.  I had bigger fish to fry – how the Earth and other planets formed.  I knew scientists didn’t really know exactly how life began, but I figured they would find out soon enough.  It wasn’t for me an important question for a long time.

(An aside: I sometimes wonder whether I would have become obsessed with life’s origins, had I went further in the direction I explored my senior year in college.  I was good at chemistry in college, and I took a class called Thermodynamic Geochemistry, which sounds a lot tougher than it actually was – but it would have gotten very tough if I had pursued it.)

Probably the world's oldest religion.

Probably the world’s oldest religion: Judaism.

Meanwhile, for the scientists who work on it, the origin of life has been an unusually thorny problem.  There have been many side-tracks along the way, from primordial soup to deep sea vents to extra-terrestrial origins (panspermia).

Earth was a barren place before life, and water only appeared in mirages (if anyone were there to see them).

Earth was a barren place before life, and water only appeared in mirages (if anyone were there to see them).

One of the first environments thought to be the cradle for life: shallows of the sea.

One of the first environments thought to be the cradle of life: shallows of the sea.

 

The State of Our Knowledge of Life’s Origin

We don’t really know what kind of environment hosted the first life.  It could have been in a thermal area, or in ice, or even in solid rock.  It could have been on Mars.  But wherever it was, water very likely was the dominant substance surrounding the primitive beings.

The clear pools at Semuc Champey in the Guatemalan highlands invite a cooling swim.

The clear pools at Semuc Champey in the Guatemalan highlands invite a cooling swim.

Perhaps a non-living compound underwent some chemical transformation into RNA.  RNA can do the work of forming proteins (as it’s doing right now inside you) but it can also reproduce, like DNA.   Then it’s just a matter of finding itself in the right place at the right time (pre-cells), to be put to work in an entirely novel way in something we would now call alive.

Clay is thought to be a likely place for pre-living chemistry to have taken place.

Clay is thought to be a likely place for pre-living chemistry to have taken place.

Or perhaps non-living structures similar to our body’s cells first started to form in high-energy environments (like deep sea vents) and they began to process energy (it’s thermodynamically favorable).  Then they began to reproduce (via RNA).  Most scientists believe that RNA is an important key.

Life was born because chemical compounds were formed at great odds.  Here salt crystals form naturally when pools evaporate in the desert.

Life was born because chemical compounds formed at great odds. Salt crystals form naturally when pools evaporate in the desert.

Perhaps you know of Craig Venter.  He’s the guy who led the team who first decoded the human genome.  He’s at work now on trying to create a living organism with no biological parents (actually a computer takes the parents’ place).  Many believe that creating life ourselves is necessary before we can understand how it arose.  As Richard Feynman once said, “What I cannot create, I do not understand”.

Active volcanoes (this one in Indonesia) could have easily provided a spark for the origin of life.

Active volcanoes (this one in Indonesia) could have easily provided a spark for the origin of life.

You can see there is some uncertainty here, and every good chemist knows these transformations are not at all easy.  But it happened.  Stuff happens after all, and given a lot of time and the right environment, perhaps life has been emerging  everywhere, throughout the history of the universe.  So what if we can’t explain the moment of life’s creation.  Does it matter?

Did life come from another planet to seed Earth's lifeless oceans?

Did life come from another planet to seed Earth’s lifeless oceans?

I tend to think that life in this solar system evolved on Earth first, but I wouldn’t bee too surprised if it started on Mars first and was transported to Earth riding on a meteor.  I also believe that this question: how did life start, is an important one.  I think it will take us a big step forward in figuring out how life emerged in the universe.  How we got here is one thing, but it will take much more insight to discover why we are here.

This story will continue, so stay tuned…

However it started, our Earth is incredibly, fully alive.

However it started, our Earth is incredibly, fully alive.

Lost Coast, California   5 comments

Eel River Sunrise

Northern California’s Lost Coast is located in northern Mendocino and southern Humboldt counties, north of San Francisco.  Steep mountains plunge down to a rocky shore.  Lonely beaches with waterfalls and good abalone hunting face out on great surfing breaks.  Just inland, wildlife abounds in the forest and small communities are separated by majestic redwood groves.

The rising sun sets the sky afire in Humboldt Redwoods State Park, California.

The rising sun sets the sky afire in Humboldt Redwoods State Park, California.

The Lost Coast includes the King Range, a rugged, steeply uplifted piece of geology with many valleys oriented parallel to the coast – a very unique situation.  California’s  western-most headland, Cape Mendocino, occupies much of the Lost Coast.  These two geographic facts give the place its isolated character.  And as usual, the geology of the region is the underlying factor driving everything.

The Lost Coast of northern California is the scene of a peaceful winter's sunset.

The Lost Coast of northern California is the scene of a peaceful winter’s sunset.

Geology

The famous San Andreas Fault, which parallels the coastline all the way north from San Francisco, leaves the coast here and merges with the offshore Cape Mendocino Fault (which runs perpendicular to the coast and out to sea).  This is where three of the Earth’s tectonic plates come together.  The North American Plate, the Pacific Plate, and the small Gorda Plate join in what geologists call a triple junction.

The plate tectonic setting for the Lost Coast of California is dominated by the triple junction just offshore from Cape Mendocino.

The plate tectonic setting for the Lost Coast of California is dominated by the triple junction just offshore from Cape Mendocino.

The slip-sliding characterized by the San Andreas to the south gives way to a subduction zone to the north.  The Gorda Plate is slipping beneath the North American Plate.  This means that a line of volcanoes lies inland.  The Cascades begin at Mount Lassen and extend north past the Canadian border.  But much closer to the coast, an enormous torquing action occurs, which is why the uplift is extreme here.  The rocks are heavily buckled and folded, forming the rugged King Range.

The part of the northern California Coast between Fort Bragg and Eureka is called the Lost Coast.

The part of the northern California Coast between Fort Bragg and Eureka is called the Lost Coast.

The coast’s spectacular scenery owes its existence to this triple junction.  Rapid uplift of a coastline is marked by frequent earthquakes and landslides, and this area is no exception.  Offshore sea stacks, for e.g., are often the result of enormous landslides in the past.  And of course landslides are often precipitated by earthquakes.  All the while erosion is taking place,  from constant wave action.  And the uplift of the coastal margin gives the waves a constant source of new rocks to erode all the time.

Ice Plant, a non-native, blooms in winter-time on the Lost Coast of California.

Ice Plant, a non-native, blooms in winter-time on the Lost Coast of California.

I stopped in the little town of Garberville, just off Hwy. 101.  It is a typical northern California town, filled with real characters.  Not all of these people, believe it or not, are old burnt-out hippies.  For the first time during this trip, I didn’t feel out of place in my VW camper.  Now if I only had a dreadlocks wig as big as one of those giant octopuses that live in the nearby ocean, I would have fit in perfectly.  Actually the town is peaceful, with a magnificent stand of redwoods nearby in the Humboldt Redwoods State Park.

A cave on a northern California beach looks out on a sunny Pacific day.

A cave on a northern California beach looks out on a sunny Pacific day.

Then I headed over the extremely curvy and hilly two-lane that leads from Garberville out to the coast at Shelter Cove.  What a road!  The last hill descending off the King Range to the coast is extremely steep, granny gear both ways.  The little settlement of Shelter Cove is spread out, and seems to be populated by people who enjoy their isolation.  I wouldn’t necessarily call them anti-social loners, but there is a reason why they live  here.  Almost 1000 people live here, but I am sure many of the spectacularly-located houses are 2nd homes.

A beach house on the coast of California.

A beach house on the coast of California.

I experienced a nice sunset, getting there early enough to explore the rocky shore below the little park.  This park is easy to find if you turn left at the first T-junction after the big downhill.  The grassy park, set up on a terrace above the sea, is centered around the Cape Mendocino Lighthouse (see below).  It’s a simple walk down to the rocky shore from this park, and you can continue south past the boat ramp around Shelter Cove itself.  The rock is black, and forms dramatic silhouettes with the numerous tide pools.  Be careful though, and consider rubber boots if you’re planning on exploring and/or photographing.  It’s slippery and there are sneaker waves.  It’s wise to remember the venerable warning to never turn your back on the ocean.

The rocky coastline at Shelter Cove on California's Pacific Coast is a tide-poolers heaven.

The rocky coastline at Shelter Cove on California’s Pacific Coast is a tide-poolers heaven.

Cape Mendocino Lighthouse

This stubby structure, which dates from 1868, did not need to be tall since it was originally placed atop a 422-foot (129 meters) cliff on Cape Mendocino.  It was shipped to the site and hauled up the steep mountainside.  The first ship sent to start construction at the site ran aground, and all supplies were lost (everyone survived though).  Over the years, the light saved many lives, and in more ways than the obvious.  For one thing it was a great lookout.  On one occasion a keeper spotted a ship that was on fire.  He brought help just in time to save all aboard.

The Cape Mendocino Lighthouse, now restored and located in nearby Shelter Cove, glows just after sunset.

The Cape Mendocino Lighthouse, now restored and located in nearby Shelter Cove, glows just after sunset.

But the frequent earthquakes and landslides were a constant hazard, and the lighthouse was eventually abandoned in the early 1960s.  The lighthouse was later saved when a local group had it moved and restored.  For the last 12 years it has shone at Shelter Cove not far south of the Cape.  But its business end seems a bit empty without its original Fresnel lens (which was replaced years ago while it was in service).

Coiled and mounded kelp is a common sight along northern California beaches

Coiled and mounded kelp is a common sight along northern California beaches

I also enjoyed some time in the redwoods at Humboldt Redwoods State Park.  There is a 2-lane road (appropriately called “Avenue of the Giants”) that parallels Hwy. 101, allowing you to stop and walk through the big trees, or enjoy the beautiful Eel River (which winds its way through here on its way to the sea).

An amazing variety of stones are present on this northern California beach.

An amazing variety of stones are present on this northern California beach.

It’s a beautiful and remote stretch of coast, one I can highly recommend visiting.  The coast both to the south (as far as Point Reyes) and to the north (the Oregon border and beyond) is also beautiful.  I didn’t get the opportunity this time to explore the Lost Coast fully.  There are hiking and mountain biking options, plus several fire roads that take off from the Shelter Cove Road.  I encourage you to go further than I did in exploring this rugged part of the California Coast.  I know I’ll do so when I return.

The Pacific Ocean and the day's last light stretch west from the Cape Mendocino Lighthouse in Shelter Cove, California.

The Pacific Ocean and the day’s last light stretch west from the Cape Mendocino Lighthouse in Shelter Cove, California.

Death Valley VI: A Cute Fish   2 comments

Blowing sand at Mesquite Flats dune field in Death Valley National Park, Califormia forms textured shadows.

Blowing sand at Mesquite Flats dune field in Death Valley National Park, Califormia forms textured shadows.

This is the last of three posts on the geology and ecology of Death Valley National Park in California.  I hope you’ve enjoyed them.  Remember for my images, click on them to be taken to the website, where purchase for download or prints (framed or unframed) is very simple.  These photos will be up in their full-sized glory soon, but if you are interested now, please contact me.  These versions are too small to do anything with, so please enjoy them without attempting to download from the blog.  Thanks.

One of Death Valley's many interesting plants, this one grows in the inter-dune areas of Mesquite Flats.

One of Death Valley’s many interesting plants, this one grows in the inter-dune areas of Mesquite Flats.

ICE AGES

Death Valley was influenced by the Pleistocene Ice Ages that started a couple million years ago and ended about 10,000 years ago.  No, glaciers did not descend into the valley; it never got that cold. But the large ice sheets to the north led to a much wetter climate throughout most of the ice-free parts of the continent.  So as you might imagine, large basins like Death Valley filled with large lakes.  At one time there were lakes hundreds of miles long.  The one that occupied Death Valley is called Lake Manly, at one time 80 miles long.  Where did the water go?  Underground of course.  You see the top of this great aquifer at Badwater, and in wet years (2004) a shallow lake reappears atop the normally dry salt flats.

A roadrunner pauses near the side of, yes, the road.

A roadrunner pauses near the side of (you guessed it) the road.

 The Great Salt Lake in Utah is the largest remnant of the paradise for water birds that the West was during the Ice Age.  This world of wetlands supported a healthy early Native American population.  As the lakes shrank and dried up some 10,000 years ago, the native groups migrated north and east, the evaporite minerals accumulated in great quantities, and desert pup fish evolved.

The sun rises and sheds a hard light on the salt flats of Death Valley, leaving the Panamint Range in shadow.

The sun rises and sheds a hard light on the salt flats of Death Valley, leaving the Panamint Range in shadow.

 PUP FISH

Can fish be cute?  Sure they can!  The cute little pup fish that make Death Valley their home are small remnants of once-huge schools that swam the huge lakes of Ice Age times.  If you know about the great Rift Valley lakes of Africa (Tanganyika, Malawi, etc.), you might know of the beautiful little aquarium fish that make those lakes their homes.  The same was true in North America during the wetter times of the Ice Age.  When the lakes dried up and separated into smaller, shallower and saltier bodies of water, those fish were forced to adapt to progressively warmer and saltier water.

 This is exactly the sort of crisis that drives accelerated rates of evolution.  It’s a changing environment that separates breeding populations into smaller and smaller parts that most easily leads to very specialized life forms, adapted to a specific environment.  In the case of the pup fish, this story has reached an extreme point in modern times at Devil’s Hole, a separate section of the National Park located not far east in Nevada.  Here live one of the world’s rarest species, the Devil’s Hole pup fish.  These small fish hide in the deep crevices of an extensive spring system.  The water, a remnant itself of a much bigger body, is incredibly salty.

Pup fish are super-specialized creatures, a testament to how difficult it is for nature to kill off one of its own.  They can withstand high salt concentrations and very warm water.  They are most likely doomed, however, as the climate of the American West continues to become warmer and more arid.   But they will continue their fight so long as we don’t do something stupid like pump nearby groundwater dry.

Snow-capped Panamint Range from southern Death Valley's Saratoga Springs.

Snow-capped Panamint Range from southern Death Valley’s Saratoga Springs.

The sand dunes at Mesquite Flats in Death Valley, California, appear wave-like in the right light.

The sand dunes at Mesquite Flats in Death Valley, California, appear wave-like in the right light.

I hope this little tour of one of my favorite playgrounds has made you want to visit, has given you a good knowledge background, and spurred you to do some additional research.  There is plenty of good information on the Web, and not all of it on Wikipedia!  I also hope this has given you an appreciation for how the geology of a region influences almost everything else about it.  It’s even true where you live!

I apologize for not writing quite so much on desert ecology.  Hmm…maybe I should do just one more post!

The pristine sand dunes in a less-visited part of Mesquite Flat in Death Valley National Park glow with a purplish hue at dusk.

The pristine sand dunes in a less-visited part of Mesquite Flat in Death Valley glow with a purplish hue at dusk.

Death Valley V: Geologic History   Leave a comment

The morning sun hits the Panamint Range, as viewed from Death Valley.

The morning sun hits the Panamint Range, as viewed from Death Valley.

This is the second of three posts on the natural history background for a visit to Death Valley National Park in California.  I hope it sparks some interest in these subjects, because if you visit this desert park, you will be hard-pressed to ignore its stunning geology and arid ecology.

GEOLOGIC HISTORY

The rocks exposed in Death Valley go back nearly two billion years.  As you walk through canyons like Titus or Marble, you will see layer upon layer of a dark gray sedimentary rock (often weathering red to orange).  A great thing to do on a hot day in a canyon is to go into the shade of these walls and lean your whole body against the cool gray rock.  This is limestone, and it tells of a time when this area was covered in a warm subtropical sea.

The famous Artist's Palette in Death Valley as viewed from atop the ridge that is most often photographed.

The famous Artist’s Palette in Death Valley as viewed from atop the ridge that is most often photographed.

Back in Paleozoic time (250-600 million years ago), there was a quiet coastline not far east of here one very similar to the modern Atlantic coast of North America.  Marine algae and other small creatures pulled CO2 and calcium out of the seawater to form their shells. These lime muds accumulated layer upon layer, eventually to become limestone.  Sand, silt and mud covered the shallow marine shelf at times, leading to sandstone, siltstone and shale.

Later, during the time of dinosaurs (the Mesozoic), the whole region was the focus of mountain building, thus emerging from the sea.  And mountain building means plate tectonics.  At that time, the ancestral Pacific Plate (called the Farallon Plate by geologists) pushed underneath the western edge of North America – a subduction zone.

Recently formed salt crystals decorate the floor of Death Valley in California.

Recently formed salt crystals decorate the floor of Death Valley in California.

The incredible pressures generated along this subduction zone made the limestone and other rocks pay dearly for being in the wrong place at the wrong time.  These sedimentary rocks were originally deposited in horizontal layers, and as you can easily see in the naked mountains of Death Valley, they have been folded, faulted, and otherwise tortured.  Masses of granitic magma, melted crustal rocks from below, pushed up into the sedimentary rocks.  This granite is best exposed to the south, in Joshua Tree and other parts of southern California.

A view of Death Valley from above Artist's Palette shows the playa with its salt pan.  A large alluvial fan is at upper left with dark inselbergs emerging in places.

A view of Death Valley from above Artist’s Palette shows the playa with its salt pan. A large alluvial fan is at upper left with dark inselbergs emerging in places.

The spectacular results of this ultra slow-motion collision can be seen on any canyon hike in Death Valley.  In addition, many of the rocks have been changed – metamorphosed – into a wholly different kind of rock.  The uplifted area was slowly worn down by erosion over a long, long time, eventually forming a low plain.  In other words, there were no rocks formed, in this case from the Jurassic to the Eocene, a period of 130 million years!  The missing time interval shows up as an ancient erosional surface in the rocks, what is called an unconformity.

 Unconformities are important horizons in any rock sequence, and this one shows itself in various places across Death Valley.  You can see a textbook example of an angular unconformity (the most obvious kind) in Darwin Canyon.  This canyon is about 19 miles from Panamint Springs (where you’ll ask for directions and road conditions).  It shows as a line in the rocks (surface in 3 dimensions) where layers below are at a completely different angle than those above.  In the same area is some fantastic folding.

Mesquite Flat in Death Valley National Park, California, offers great opportunity to photograph landscapes in black and white.

Mesquite Flat in Death Valley National Park, California, offers great opportunity to photograph landscapes in black and white.

THE BIG RIP

Long after the dinosaurs had disappeared, starting several million years ago, this area began to be torn apart by rifting at the edge of North America.  It’s a process that continues today.  By this time the subduction zone off the west coast had shrunk northward, where it still grinds away off the coast of Oregon and Washington.  It was replaced by the San Andreas Fault, which still marks the boundary between the North American and Pacific tectonic plates.

The lateral sliding movement of the enormous Pacific Plate moving north past the western margin of North America is essentially torquing the entire western part of North America.  It’s caused a clockwise rotation and the crust has broken into large fault block mountain ranges bounded by normal faults.  This rifting (as rifting typically does) opened pathways for lava to rise and erupt.  Throughout Death Valley you will see areas of volcanic rocks – mostly tuff (rock made from volcanic ash) and basalt (dark lava rock).  Ubehebe Crater in the north past Scotty’s Castle is just one example.

The skies above Death Valley are the playground of Navy pilots from nearby China Lake.

One of the only times you’ll look up from the stunning landscape of Death Valley is when a deep boom makes you notice the Navy jet pilots from nearby China Lake, who make the skies their playground.

 The fault-block mountains caused by rifting are Death Valley’s most obvious geological structure.  But in this far southern part of the Basin and Range, you are looking at a deeper level of rifting.  So there are not only the steep normal faults, but also low-angle “detachment” faults.  Think about the steep normal faults that border the mountain fronts curving and taking on more shallow angles as you mentally travel down their surfaces, and you have a great idea of a detachment.

Incidentally, remember the granite formed during the Mesozoic?  Go south, to Joshua Tree and other places in Southern California, and you’ll see the masses of granite all around.  This means you are seeing much deeper levels of the rifting of North America than you see in the northern Basin and Range.  Keep going and you’ll come to the Gulf of California, where the Sea of Cortez has already invaded the rift.  It’s as if a giant zipper was slowly opening, south to north along the western edge of the continent.

A black and white rendition of the simple beauty of Death Valley's sand dunes.

A black and white rendition of the simple beauty of Death Valley’s sand dunes.

 Back to detachment faults: they can cause whole mountain ranges to literally slide down a sort of shallow ramp, ending up miles from where they started.  Tucki Peak may have slid in this manner.  They really are the most efficient way to rip apart a continent!  You can see these large, low-angled surfaces where they help to form the geographic features called turtle-backs.  One such site is about 16 miles south of Badwater, where if you stop at Mormon Point and look north into the Black Mountains, you’ll notice one of these ramp-like detachment faults.

One more post coming to finish up with Death Valley, this one on the Ice Ages and the pup fish.

The golden light of a late afternoon warms the dunes at Mesquite Flat in Death Valley National Park.

The golden light of a late afternoon warms the dunes at Mesquite Flat in Death Valley National Park.

Death Valley IV: Geologic Features   Leave a comment

This is the first of three posts on the geology and ecology of Death Valley National Park in California.  Death Valley is Disney Land for geologists, and for anybody interested in earth science.  What isn’t as well appreciated is it’s also a very special place for desert ecologists and botanists.  But first the geology:

A colorful dawn breaks over Death Valley National Park in California.

A colorful dawn breaks over Death Valley National Park in California.

Since it is the driest place in North America, vegetation does not cover geologic features at Death Valley.  And since it lies in a place where there’s been a lot of geological action for an awfully long time, there exist a great variety of rock types and structures.  Regarding the latter, the whole region has been first smashed by mountain building and more recently torn apart by rifting.  Death Valley’s structure (meaning twisted and folded rocks, fault zones, etc.) shows this in dramatic fashion and is one of the major draws for geo-types.

I first visited Death Valley with my first year geology class.  We came down on Spring Break from drippy Oregon and boy was it nice to be in warm sunshine for a week.  We all got 3 credits for it, but it was a lark!  Since my professor was a biologist and avid birder as well as a geologist, he mixed ecology and raptor-spotting in with rocks for a really complete picture of this amazing place.

The soaring dunes at Mesquite Flat in Death Valley National Park, California.

The soaring dunes at Mesquite Flat in Death Valley National Park, California.

GEOGRAPHY AND CLIMATE

Death Valley is an enormous trench.  The vertical relief from Badwater at -283 feet elevation to the top of Telescope Peak is about 11,300 feet (almost 3500 meters)!  This giant steep-walled valley is called by geologists a graben (German for grave).  Steep fault zones, called “normal” faults, force the bordering mountain ranges up while the valley drops and fills with sediments.  This sort of faulting is repeated across the Basin and Range Province of Nevada and bordering states.

The steep mountains left by the normal faults to stand high above valley floors block moisture coming in from the Pacific and cause an extreme form of the “rainshadow effect”.  The Sierra Mountain Range, which tops out at over 14,000 feet at Mount Whitney, gets most of the rain and snow.  The Panamint Range, which borders Death Valley to the west, also gets its share.  This leaves almost no moisture for Death Valley.  That is why years can pass without any rainfall.  It is extremely arid, and this of course causes the plant and animal life to be sparse.  But the fascinating adaptations that have evolved in the life forms at Death Valley more than makes up for the paucity of biomass.

Basin and Range structure has led to two types of features.  These features, both of which are displayed at Death Valley, determine much of what goes on geographically, ecologically and even with human history here.

The extensive salt flats near Badwater in Death Valley National Park, California.

The extensive salt flats near Badwater in Death Valley National Park, California.

PLAYAS

 First thing you’ll notice are the playas (or pans), which are dried up lake beds.  These flat surfaces, which can be floored in white salts or a tan clay surface, are caused by internal drainage.  Because of the normal faulting described above, water that washes from the ranges into the basins of the Basin and Range often never makes it out along a river course. Instead, the water collects in large, shallow lakes.

When the water evaporates, salts (chlorides and sulfates of sodium, calcium, phosphorous, etc.) are left behind in the lakes.  These so-called evaporites are too heavy to be lifted into the air with the water vapor.  (This is why rainwater is fresh and why the oceans are salty.)  The salts come from weathering of the minerals in rocks of the surrounding mountains.

The full moon sets just as morning light hits the cracked salt flats near Badwater, North America's lowest point, in Death Valley, California.

The full moon sets just as morning light hits the cracked salt flats near Badwater, North America’s lowest point, in Death Valley, California.

The evaporite minerals are inevitably concentrated into the shrinking pools of water, where they crystallize into fascinating patterns.  This happens during most seasons (winters are wet and summers very dry), and so salt layers build up.  Gypsum and borax are also formed in this way.  Death Valley’s human history includes the charismatic 20 Mule Team borax story.  Near Badwater in Death Valley proper, a huge salt pan is spectacularly developed.  Take the West Side road for the best access.

 Go over to Panamint Valley in the western part of the park to see and walk on a great playa.  It was formed when fine sediment was deposited instead of pure salt.  Certainly Death Valley’s best-known example of this is Racetrack Playa, where stones appear to have skated across the playa, leaving behind their tracks.  It’s still uncertain how they move, but winds and a thin layer of ice probably have something to do with it.  Note that to visit the Racetrack in the far northern part of the park requires driving a long, long washboard gravel road.  And to make things worse, the road bed is made of especially sharp gravel, so you’ll need very good tires (and two spares).

A close view of the ridges that form the salt polygons at the Badwater salt flats, Death Valley N.P., CA.

A close view of the ridges that form the salt polygons at the Badwater salt flats, Death Valley N.P., CA.

ALLUVIAL FANS

But mostly what you’ll see in Death Valley are the other feature that result from Basin and Range faulting.  As you drive through the park, one thing you’ll notice is that this is a rocky desert, not so much a sandy one.  As you look across the valley, you’ll notice large semi-circular (fan-shaped) gravel features that narrow to a point at the canyon mouths.  These are alluvial fans, and they form everywhere that rapid uplift of mountains overwhelms the ability of rivers to transport the debris out of there.

Try walking up an alluvial fan and you will get a feel for their deceptive steepness and difficult, loose surface of cobbles.  But it’s a great education on how they form.  You’ll also see desert varnish, a dark, sort of rust that forms on the rocks when they sit undisturbed for a long time.  I rarely link to Wikipedia, but heck, go ahead and check out desert varnish.  It’s an  interesting, part living feature of the Mojave.

A black and white rendition of the simple beauty of Death Valley's sand dunes.

A black and white rendition of the simple beauty of Death Valley’s sand dunes.

When alluvial fans merge into a wedge of debris that flanks the entire range of mountains, it is called a bajada.  Eventually the mountains disappear and all that’s left is a gravel plain.  Namibia has extensive ancient gravel plains, but the American West is really much younger.  Large outcrops that stick up island-like out of alluvial fans or bajadas are called inselbergs.  Great words in geology!

I’ll get to the “rest of the story” in my next post.  I miss Paul Harvey!

The pre-dawn hours in Death Valley's sand dunes promises a beautiful sunrise.

The pre-dawn hours in Death Valley’s sand dunes promises a beautiful sunrise.

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