A California Love Letter: It's the Best Geology to be Found Anywhere!

This is the second of some resource materials I have on our college website that are being removed, so I wanted to preserve them. The following is some info I give to my students of my "Geology of California" course. For the majority of these students, it is their first introduction to geology, and their first introduction to the extraordinary state that is their home. For a more complete explanation of each superlative, click on the orange links (down the rabbit hole!). Enjoy!

Highest point in the lower 48 states: Mt. Whitney, 14,505 feet 

Lowest point in the western hemisphere: near Badwater, Death Valley, -282 feet

The deepest canyon in North America (maybe): Kings Canyon, Giant Sequoia National Monument. Hells Canyon on the Oregon/Idaho border may be 19 feet deeper. Maybe...

Largest living things in the world: Sequoia Trees

Tallest living things in the world: Coast Redwoods

Oldest living things in the world: Bristlecone Pines (5,000 years), White Mtns, or Creosote Bushes in Colorado Desert (11,000 years)

My Scottish BBC Interview at a relatively balmy 110 degrees

Hottest Place on the Planet and Driest Place in North America: Death Valley: 134 degrees, precipitation 1.4"/year

One of the Snowiest Places in the U.S.: Tamarack, Sierra Nevada, 76 feet in one year, 32 feet in one month, 37 feet on ground at one time

Highest Waterfall in the North America (no. 7 in world): Yosemite Falls, 2,425 feet

Second tallest active volcano in the U.S.: Mt. Shasta, 14,162 feet

Second most recently active volcano in lower 48 states: Mt. Lassen (1914-21)

Most voluminous volcano in the lower 48 states: Medicine Lake Highland (around 130 cubic miles) in northeastern California

Scarp from the 1872 Lone Pine earthquake

Some of the largest earthquakes in the lower 48 states: 1906 (San Francisco 7.8), 1872 Lone Pine (7.8), 1857 (Ft. Tejon 7.8)

Old oil derrick near the Santa Clarita Valley

One of the more prolific oil and natural gas producing regions in the world: Los Angeles Basin, Bakersfield, and Santa Barbara-Ventura Channel

One of the biggest explosions ever: Long Valley Caldera, 750,000 years ago, 125 cubic miles of ash spread all over the western states as far east as Nebraska and Kansas

McWay Falls at Julia Pfeiffer-Burns State Park on the Big Sur Coast

No other state has the combination of landscapes: Coastlines, deserts, mountains, river valleys and plateaus, due in no small part to the fact that California is influenced by all three different kinds of plate margins: Divergent, convergent and transform. Few places in the world have this kind of diversity.

The San Andreas fault on the San Francisco Peninsula. San Andreas reservoir, from which the fault took its name, is in the foreground.

What would you add to this list???

Driving Through the Most Dangerous Plate Boundary in the World: The "Dr. Who" of Mountain Ranges

The Whitney Crest of the High Sierra. Mt. Whitney is just out of sight to the right.

I was torn over the title for this addition to the "Driving Through" blog series. I thought of taking the zombie approach and calling them the living dead mountains ("they keep coming at you"), or the crazed killer angle ("they're never truly dead"), but these seemed...um...overly negative for a mountain range that I love. Then it occurred to me that there is a well-loved media character who is regularly mortally wounded and is regenerated with a new body. And Doctor Who is certainly loved by millions of rabid fans. And that seemed a good analogy for the Sierra Nevada of California. The mountain range has been uplifted, deeply eroded, rejuvenated, eroded, and risen yet again, and the mountains have been different each time.

Tenaya Lake and Mount Conness in Yosemite National Park

The are at least three different mountains that occupied this part of California in the last 400 million years, and most of them were related in some way to convergence, the subduction of sea-floor lithosphere beneath the western edge of the continent. The most recent incarnation of the Sierra Nevada has an enigmatic origin, and many uncertainties remain about the specific mechanics of uplift. But rising they are, even to the present day.

Highly deformed calc-silicate metamorphic rocks in Kings Canyon near Boyden Cave.

The earliest mountains were related to the collision of exotic terranes with the western edge of North America. Some of the rocks had their origins in early Paleozoic time, and were severely deformed during the Devonian period roughly 400 million years ago. Some researchers have related the deformation to the Antler Orogeny that is best revealed in central Nevada. Had one been there at the time, the scene might have been reminiscent of some of the complicated island arcs in Indonesia.

Highly folded slate near Dial's Rock Shop near Mariposa, west of Yosemite National Park

By Triassic time, about 250 million years ago, subduction zones were directly active along the west coast of North America, and chunks and bits (the exotic terranes) became incorporated into the continent itself. Mountains were pushed up along the coast in much the same way as mountains have formed in southern Alaska, but without the glaciers. The edge of the continent was located closer to the equator than today.

Mt. Shasta, in northern California, as a stand-in for the Ancestral Sierra Nevada

By late Jurassic time, about 150 million to 85 million years ago, the so-called Ancestral Sierra Nevada mountains pierced the sky. Subduction was feeding vast batholiths of granitic rock deep in the crust, and large volcanoes and calderas caused mayhem at the surface. These mountains may very well have resembled today's Andes Mountains, and indeed, the margin at that time is referred to as the Andean-style plate margin. And then...the mountains died away again. A massive erosional unroofing began that removed 5-6 miles of overlying rocks, exposing the granitic rocks. Evidence strongly suggests that the mountains had been laid low, to mere hills (although contradictory research exists). Sedimentary rocks from 40-50 million years ago show a system of coastal marshes and estuaries, sandy beaches, and large rivers with sources in at least central Nevada, and possibly farther inland.

Much of the western Sierra Nevada is composed of gently sloping, deeply eroded metamorphic rock, covered here and there by volcanic mudflow deposists (lahars), and ash tuff.

It's only been in the last few millions or tens of millions of years that the present-day Sierra Nevada began rising to their present-day prominence. The mountains rose as a westward tilted block, outlined by major faults on the east side, and the Great Valley of California to the west. As the mountains rose, deep valleys were carved by the westward flowing rivers like the Kings, Merced and Tuolumne. In the last two million years, global cooling brought about a series of ice ages, and glaciers scoured the upper parts of the river valleys, giving rise to the spectacular gorges that we visit today, Yosemite Valley being the epic example.

Yosemite Valley from the vicinity of Turtleback Dome.

So, our drive through the most dangerous plate boundary in the world will continue, following pathways into the heart of this mountain range that is both ancient and youthful at the same time.

One of the Most Astounding Viewpoints in America: At the Outer Ring of Hell (but not really)

A place not to missed. That's what I have to say about Dante's View in Death Valley National Park. And if you ever get there, don't just stand in the parking lot. Short walks in several directions offer even better views of the incredible landscape surrounding the lowest place in North America. Death Valley may get hellishly hot sometimes, but it's not a view of hell but is instead a dramatic perspective of some of the most interesting geology in the American West.

The Black Mountains form the eastern margin of the deepest part of Death Valley, almost directly across from Telescope Peak, at 11,043 feet (3,366 meters) the highest point in the park. The viewpoint is a bit over a mile in elevation at 5,476 feet (1,669 meters). From the viewpoint one can take in almost the full length of Death Valley, a distance of more than 100 miles. Once also look east across the numerous mountain ridges of the Basin and Range geological province to Charleston Peak above Las Vegas, Nevada. A few summits of the Sierra Nevada peek out over the ridge of the Panamint Range across the valley.

Directly below one's feet is a steep one mile drop to Badwater on the valley floor. The slope is so steep that the parking lot and Badwater pond are not visible, but very small humans can be seen on the white trail leading out to the salt flats, and very small cars can be seen driving on the highway that circles the edge of the alluvial fan.

Here's a zoomed shot to see the people a bit better...

The Black Mountains are composed mostly of the oldest rocks in the region, a complex of gneiss and schist dating back 1.7 billion years. Similar rocks are found in the depths of the Grand Canyon in Arizona. They were once covered by several vertical miles of Paleozoic sedimentary rocks, but those rocks have slid westward to form the Panamint Mountains. The gap between became the graben of Death Valley itself.

The rocks making up the summit area are volcanic rocks, mostly rhyolite, which were erupted in violent eruptions around 6-7 million years ago. Such rocks have been found across the Basin and Range province, indicating extensional stretching and failure of the crust, which ultimately formed the grabens and horsts of the region.

I take my use of superlatives in describing viewpoints seriously. You can see my ten (eleven, actually) most precious "spots" in the world, and Dante's View is on that list. There may be other places in the world that allow one to see far, but I suspect few reveal a more stunning and fascinating landscape.

There is a myth sometimes repeated that one can see Mt. Whitney from Badwater, which is simply impossible because the Panamint Mountains rise 7,000-8,000 above the adjacent valley floor. One can see the tips of several Sierra Nevada peaks from the hill north of the parking lot at Dante's View, but I think the highest peak visible is Mt. Williamson at 14,389 feet (4,383 meters). It is possible to simultaneously see both the highest and lowest points of the conterminous United States, but you have to find your way to the summit ridge of the Panamint Mountains and Telescope Peak to do so.

It's truly a place and a view not to be missed.

The Sierra Beyond Yosemite: A Stunning Impenetrable Wall of Solid Rock

Mount Whitney from the Alabama Hills in the Owens Valley

Impenetrable. The imaginary mountain barrier surrounding Mordor in the Lord of the Rings has nothing on this real-life wall of solid granite. For more than one hundred miles, from Mono Lake south to Owens Lake and beyond, there is a 10,000+ foot high crest that divides California from the rest of the country, which stops almost all precipitation from Pacific storms, and which denied immigrants an easy path to the gold-fields of the Mother Lode.

The Wheeler Crest from Bishop in the Owens Valley

The Sierra Nevada is a barrier to travel of all kinds: paths, wagon trails, roads, and railways cross the mountains in only a few places, and those few places present serious engineering challenges. No paved roads cross the mountains for well over 150 miles between Tioga Pass in Yosemite National Park, and Walker Pass south of Sequoia National Park (The only minor exceptions: Sherman Pass, a paved former logging road is inappropriate for heavy traffic, and a dead-end road that travels to Devils Postpile). The only freeways exist at Donner Summit and Tehachapi Pass.

The Sierra beyond Yosemite provides some of the most stunning scenery on the planet. On the previous day of our fall trip we had crossed the Sierra Nevada at Sonora Pass, and explored the ghost town of Bodie, but the sun was disappearing in the west by the time we arrived at our campsite in the little town of Bishop in the Owens Valley. For those on our trip who were seeing these lands for the first time, it was a revelation to wake up to the high remote ridges of granite and metamorphic rock that towered over the flat valley floor.

Mt. Humphreys (13,996 feet) above Bishop, California in the Owens Valley

Many would say that Death Valley is the ultimate expression of basin and range style geography, and in many ways it is extraordinary, but few valleys in the world can match Owens for pure grandeur. One one flank, the Sierra Nevada rise to elevations exceeding 14,000 feet. On the other, the White Mountains average 11,000 feet, culminating in White Mountain Peak at 14,252 feet. Given the roughly 4,000 foot elevation of the floor of Owens Valley, the declivity is twice as deep as the Grand Canyon. Comparisons are unfair, of course, since the Grand Canyon is water-carved, and the Owens is of fault origin, but the scale of the landscape is grand in any case.

The origin of the wonderful scenery is a two-edged sword, of course. The faults that formed the Owens Valley are still very active. In 1872, the Owens Valley fault was responsible for one of the biggest earthquakes in the state's recorded history. The magnitude 7.8 event killed 27 people (out of a total population of around 300), and shifted the ground dozens of feet along a scarp more than eighty miles long.

The Palisades Group of peaks on the Sierra Crest from Sierra View in the White Mountains

One of the most spectacular ways to see the mountain wall is to climb into the White Mountains and see most of the Sierra escarpment from one view point. It's called (by incredible coincidence) Sierra View, which is a pullout on the equally spectacular road to the Ancient Bristlecone Pine Forest. From the one view, one can see the Sierra Crest from the Tioga Pass area to south of Mt. Whitney, a distance of over 100 miles. We were blessed with a clear morning despite the fires raging throughout the region.

Later in the day we drove south to Lone Pine, which lies on the floor of the Owens Valley beneath Mt. Whitney, which at 14,505 feet is the highest point in the lower 48 states. After a number of stops, we ended up at an old mine, the Reward, and watched the sun sink over the high ridges.

Sunsets for the people of the Owens Valley are different. There is no horizon over which the sun emerges or sets. There are only high ridges. When the conditions are right, the light show is wonderful.

A Gallery of Sierra Nevada Scenes: Part II

Alabama Hills near Movie Flats

I picked out some more scenes from our recent field studies class in the eastern Sierra Nevada and Owens Valley. Above, the Alabama Hills expose granitic rock essentially similar to that of the rugged high Sierra. It looks different because it weathered beneath the surface, possibly in more subtropical conditions. Cracks and fractures allow water to seep onto the surface of the granite, breaking the feldspar minerals down to clay and removing corners and edges over time.

Devil's Postpile National Monument near the headwaters of the San Joaquin River

The Devil's Postpile is a famous example of a different process of breaking up rock. When lavas flows back up and form pools, the cooling rock contracts and fractures into hexagonal shapes (although columns with 4, 5, and 7 sides are known). It is somewhat unusual to see such straight columns; they usually are far more irregular.

Mamie Lake at Mammoth Lakes

The Mammoth Lakes are a series of beautiful glacially carved tarns (some enhanced by small power generating dams). Mamie Lake is seen above, and the Twin Lakes below.

A storm blew through in the midst of our journey. The morning after brought smoke-free conditions and beautiful sunlight through the clouds. The picture below shows Mt. Tom and Mt. Humphreys west of the town of Bishop in the Owens Valley.

One of the best ways to see the Sierra Nevada is to view the range from the next ridge over. The White Mountains in any other setting would be a celebrated National Park. It is a stunning wall of rock with unique topography and unique biology. We climbed the road to the Schulman Grove of Bristlecone Pines across from the Palisades Crest of the Sierra Nevada.

Palisades Crest from the White Mountains. The Owens Valley is in the foreground.

The Palisades Crest is home to the largest remaining glaciers in the Sierra Nevada. The biggest is about a half mile long and a mile wide. In this drought year, few snow patches were left...pretty much all the ice you see in the picture above is a glacier.

The Bristlecones are special trees. Besides living in one of the toughest environments of any tree in the world (two miles in elevation, with a two or three month growing season), they grow to great antiquity. The oldest discovered thus far is more than 5,000 years in age.

The trees subsist in nutrient poor soils, but even poor soils are better than the barren debris formed on pure quartzite. The forest ends abruptly where the Cambrian quartzite begins.

The day included a spectacular view of clouds curling around the summit of Mt. Whitney (14,505 feet; 4,421 meters), the highest mountain in the lower 48 states. The spheroidally weathered boulders of granite in the Alabama Hills can be seen in the foreground.

The last day of our trip was clear, providing a beautiful view of the metamorphic rocks above Convict Lake south of Mammoth Lakes, and the tufa towers at Mono Lake. Some detailed geologic descriptions of these fascinating places are in the works for a future blog post.