Sunday, May 26, 2019

What to do on a Saturday? Let's Go to the Middle of the Earth (via Del Puerto Canyon)!

The strange and alien landscape in upper Del Puerto Canyon.
California has some really strange landscapes. A state that has beaches, mountains, volcanoes, forests, and deserts is going to offer many perspectives of the complex geological influences on the state. But for alien and otherworldly, few places in the state can compare to the journey you take when you follow Del Puerto Canyon from its mouth in the Great Valley to the headwaters in the Diablo Range. It's a journey into the middle of the world. Our Geology Club made the trip a few weeks ago as an ending of the semester celebration. Odd way to celebrate? Did you simply party? We traveled half-way to the center of the planet!
"Del Puerto" refers to "The Gate", the constriction of hard sandstone at the mouth of the canyon.
I guess I should be a bit more specific. We journeyed to rocks that had once been part of the Earth's mantle, the 1,800 mile thick layer that lies just beneath the thin crust (3-50 miles thick). We couldn't reach the core of the planet, because no one can (despite sci-fi movies that say otherwise). Since mantle rock is very hot and is subject to convection, it is at least conceivable that the rocks we explored had once been close to the Earth's core.
So how does one explore the Earth's mantle? Well, first one has to get through the crust, and the thinnest crust is that which makes up the ocean floors. It's nominally composed of basalt, but the details are more complex.

In Del Puerto Canyon, the ocean floor is covered by...a bit of sediment. About 25,000 feet of it! The sediments poured off the mountainous edge of the continent during the later part of the dinosaur era, the Cretaceous Period. There was a huge subduction zone that formed as oceanic crust plunged into the mantle beneath the edge of the North American continent. This so-called Cascadia Subduction Zone caused volcanoes to form where the Sierra Nevada is today, but the area offshore of the volcanic arc, the forearc basin, collected sediments. As the sediments accumulated, they pressed the crust downward and even more sediment piled on top. Eventually the layers reached a thickness of five miles.

The basin collected fossils as well. There were the usual shells of clams, snails and ammonites, a variety of shark teeth, and three groups of seagoing reptiles, the plesiosaurs (think Loch Ness), ichthyosaurs (think reptilian version of a dolphin), and 35-foot-long mosasaurs (think "swim for your life!"). Even dinosaur fossils have been found. The first dinosaur ever found in California, a Saurolophus, was discovered in the lower reaches of Del Puerto Canyon in 1935.

Eventually, one will reach the base of the oldest sediments, and encounter the ocean crust itself. Faulting obscures some of the relationship, and so in the picture below we see some of the oldest sediment on the right (somewhat brownish shale) and basaltic/andesitic volcanic rock on the left (greenish gray), separated by a fault. The volcanic rocks are harder, and the canyon takes on a more rugged aspect as we climb higher into the mountains.
The Coast Ranges of California are one of the youngest mountain systems in the world, having been uplifted mostly in the last 3 million years or so. The streams in this dry environment have not been able to downcut as fast as the mountains are rising, so they flow much of the way over bedrock. There are few floodplains in these mountains.
The water flows almost year-round and thus the canyon is a critical habitat for all kinds of wildlife. Dozens of mammals and reptile species are known, and nearly 200 bird species have been observed here.
Oceanic crust is basaltic in composition, but there are differences at depth. On the ocean floor, basalt flows form "pillows", globular masses of the volcanic rock. Beneath the pillow basalts, basaltic dikes fed the eruptions. Dikes occur when volcanic rock fills cracks and fissures in the surrounding rock. Since the surrounding rock is also dike material, the entire layer, a mile or two thick, is made of vertical sheet dikes. Feeding these dikes were magma chambers composed of...basalt! But some of the basalt was left at the base of the oceanic crust where it then cooled slowly to form a sparkling crystalline rock called gabbro. The entire suite of rocks is called an ophiolite sequence. The Coast Range Ophiolite sequence in Del Puerto Canyon is considered to be the second best exposed in the state, behind the Point Sal Ophiolite in southern California.

We stopped in one of the most rugged parts of the canyon to investigate the gabbro where it was pierced by a vein of quartz (below). People have looked for gold here, but I doubt they found any.

Just a few more miles up the canyon and we penetrated the uppermost part of the mantle. The rock originally consisted of ultramafic minerals like olivine and pyroxene, but here the rock has been metamorphosed into serpentine, California's state rock. The rock was sheared and faulted on its way to the surface, leaving shiny green and black polished surfaces (below).
And then we were there. In the uppermost part of the canyon, we reached the netherworld of mantle rock that was far less altered, so that it retained some of its original appearance. In places we could see olivine and pyroxene crystals, as well as grains of chromite. These ultramafic rocks contain few nutrients needed by plant life, so only a few species can tolerate living on these slopes. Gray pines are among them, grasses generally are not. There are a number of wildflower species endemic to California that can be found here.
Looking at these shattered broken rocks from very deep in the Earth, one imagines hell freezing over. The forges of the demons and devils lie frozen in place, to be slowly removed by earthly weathering. They tried to invade the surface realm, but they were defeated by the forces of the heavens, the water and ice falling from the sky.
It may have been a metaphorical battlefield, but in the end there is great beauty in the rarity of the flowers, plants and animals that thrive, or at least tolerate the conditions in the upper canyon.

We turned around and headed back to more familiar habitats.

Del Puerto Canyon is traversed (slowly) by Highway 130, originating in Patterson on the floor of the
Great Valley. It can also be reached by way of Mines Road out of Livermore, or  a winding road out of the San Jose area over Mt. Hamilton and the Lick Observatory complex. It is not a fast way to go!

Saturday, May 18, 2019

The Eruption of Mt. St. Helens at 39 Years: Why It Still Matters

It is the 39th anniversary of the famed eruption of the St. Helens volcano and as I think of those days, I realize that even though a majority of the population wasn't even alive at the time, the volcano still matters. Not because of the potential for future eruptions (although that remains a distinct possibility), but because of the way we process and deal with the natural hazards that we all face, no matter where we live.

When the volcano began rumbling and sending ash into the atmosphere, we had only a few avenues to get information, mainly television news, radio, and newspapers. I think now how limiting these sources were compared to the nearly instantaneous delivery of news over the internet in the present day. We can look up earthquakes just moments after they happen, and webcams allow us to monitor volcanoes around the world in real time. There is both good and bad in this profound change. There were terrible sources of news in those olden days, like the Weekly World News or the National Enquirer, but they pale in comparison to the sewage found on the internet today. Back then, national news outlets and newspapers practiced careful journalism in most instances, but it often seems today that the only reward for excellence and honesty in reporting is decreased ratings and falling revenues. To get attention in a crowded internet environment media outlets have to dress their stories in shiny objects and provide them with the worst possible clickbait titles. In the olden days we often had to wait impatiently for information about natural disasters, but the information that came through the media was more often vetted and checked for accuracy. The journalistic filters today are completely gone, and it can be difficult to distinguish between the trash and the truth.

There are so many conspiracy theories floating around today about natural disasters and potential disasters. The eruptions of Steamboat Geyser in Yellowstone National Park numerous times after years of quiescence has caused a blizzard of posts on the internet pondering whether Yellowstone has been disturbed and may blow as a "supervolcano" eruption soon (and we'll all die). The same has happened after a number of recent small earthquakes. But a reading of the reality-based data says that Yellowstone caldera has not had a lava flow or eruption of any kind in 70,000 years, and no knowledgeable geologist sees any evidence of precursors to any new eruptions. A few years back, an earthquake and an internet video of a group of bison running "away" from Yellowstone caused the same kind of internet speculation (it turns out the bison were running towards the caldera).

Of course it is true that the Yellowstone caldera was born in one of the most colossal eruptions ever recorded. Learning the story of the eruption of the Huckleberry Tuff is fascinating. It brings an entirely new appreciation of the incredible scenery to be observed in a place that contains 70% of all the world's geysers. It should be enough. But there are so many individuals out there who would like to make a buck by scaring people needlessly. And there are too many gullible and ignorant people out there who can't pick rational accounts out of the confusing mix of conspiracy theories that exist on the internet.

And then there is the Big Island of Hawai'i. There were some serious and tragic things going on last summer as the longest eruption in history reached a climax. The activity endangered lives and destroyed homes as Kilauea underwent major changes from the "norm" of the eruptions that had been ongoing for the last 35 years. The U.S. Geological Survey and Hawaiian civil defense authorities did a pretty good job of providing up-to-date information about the latest activity, but that didn't stop all kinds of stories from popping up on the internet about the "Ring of Fire" which has nothing at all to do with Hawai'i. It was just too easy to pick up stories of eruptions in Alaska and Indonesia and think there was a pattern of increasing volcanism or earthquake activity (OMG, a magnitude 6 quake in the Kermadec Islands and an eruption at Mt. Cleveland in Alaska! It's a pattern and therefore Seattle will fall into the sea very soon!). The problem is one of perspective: if you had signed up for earthquake notifications and volcano advisories from the USGS or other geologic research institutions, you would have realized that these things happen all the time, and that a cluster of events is not unusual.

It's one thing to make up stories about normal volcanic activity to scare people. One can argue that they are ultimately harmless because the eruptions aren't actually taking place or hurting anyone. But there are real-world consequences of ignoring journalistic standards. Many of those who make their money with false headlines about such things will also traffic in climate change denial. When science becomes a matter of believing whatever one wishes, the very real problem of global warming becomes just another "scare" story, and the alarm bells being sounded by climate scientists become just more noise in an internet full of noise. But the real-world consequences are happening now, and action is needed to counteract the changes or to stop them. But it has become too easy to ignore the problem because it is so incremental and slow-acting. It just can't compete with the shiny baubles and clickbait on the web.
People in Hawai'i mostly trusted the geologists who studied the volcanoes all their lives and thus made the correct decisions about evacuating homes and businesses. In the same way they trusted the seismologists when a tsunami threatened the islands in 2011 after the massive earthquake in Japan. No lives were lost when the tsunami hit because people had evacuated the low-lying areas. The wave surge was 8 feet deep in places and caused millions of dollars of damage. Many people could have been killed, but they accepted the authority of the scientists who predicted the timing and magnitude of the seismically induced waves.

And that's why the Mt. St. Helens eruption of 1980 matters today. Scientific expertise matters. Climate change is an even more profound danger to society than any earthquake or volcanic eruption. We need people to give climate scientists the same kind of respect they give geologists when volcanoes are rumbling and smoking. They are the ones to listen to, not the hucksters on the internet who are out to make a buck, or trying to protect those industries that make their profits off of producing greenhouse gases. We seem to talk little these days about integrity and striving for excellence, but scientific researchers are among those who still have those traits. There are always exceptions, but I would trust a scientist over a politician any day of the week (unless it is clear that the politician knows how to listen to a scientist).

There is a sign seen at some of the March For Science protests that have been happening for the last two years around the country: "At the start of every disaster movie there's a scientist being ignored". Unfortunately, it is too true in real life as well.

This has been a highly abridged and updated version of last year's St. Helen eruption anniversary reflection.

Tales from the Semi-Super Bloom Tour, Part 5: Coming Home

"We shall not cease from exploration
And the end of all our exploring
Will be to arrive where we started
And know the place for the first time.
Through the unknown, remembered gate
When the last of earth left to discover
Is that which was the beginning..."
T.S. Eliot
I'm a bit behind, what with the end of the semester and all that, but there was a bit of unfinished business from a few weeks ago...the end of our Semi-Super-Bloom tour. Yes, most of the flowers throughout the west have faded and shriveled as April turned out to be very dry. In this wet year many parts of California were covered by flowers in a way not seen in a decade or more. It was a spectacle and hundreds of thousands of people converged on places like Anza-Borrego, or Elsinore, or the Grapevine in Southern California. Among the crowds there were the stupid and ignorant who trampled the flowers and in one instance landed a helicopter in a field of flowers.
Around six weeks ago, Mrs. Geotripper and I set out to find some of the less crowded places, the spots where the flowers were blooming, but they weren't quite at the level of the Super-Bloom. Our journeys carried us through the Mojave Desert, Death Valley National Park, the Merced River Canyon downstream of Yosemite, and the Red Hills Area of Critical Environmental Concern. But it was our final journey of the tour that was so illuminating: we were home. And it was a beautiful place.
We live at a nexus point, the boundary between the Sierra Nevada and the Great Valley of California. Our town is surrounded by agricultural fields, but as we drive east, the fields and orchards give way to one of the few remaining prairies in the state of California. Although large portions are being plowed over for almond orchards, the grasslands still exist in the low foothills of the Mother Lode.
The soils are old and deeply weathered, and are generally nutrient poor. It's only a few feet to bedrock as a rule, so water is not often available for plant growth, and so for most of the year the hills are covered with a brown (some say "golden") veneer of dead grasses.  But in the spring of wet years, the prairie comes alive with color. One of the unique habitats of our grasslands are the vernal pools, the hollows where water stands for a few short weeks or months in the spring. Because they are flooded part of the year and dry for the rest, they are a crucible for the evolution of unique plants and animals adapted to the harsh environment. Many of California's endemic plants are found there. There are hundreds of these vernal pools scattered across the prairie. And that's where we saw much of the color as we drove through a few weeks ago.
We were traveling on Willms Road south of Knight's Ferry on the Stanislaus River when we spotted one of California's near-endemic bird species. Red-winged Blackbirds are a familiar sight across much of North America, but there is a closely related species called the Tricolored Blackbird that is mostly found in the Great Valley and in the prairies of the foothills (they have a white stripe below their red wing spots). The birds are endangered because of an unfortunate habit they have of nesting in large colonies in the middle of grassy prairies. The problem is that they don't make a distinction between a tall-grass prairie and an alfalfa field, and thus thousands of nests and their occupants have been destroyed in an afternoon as farmers cutting and harvesting the alfalfa. Efforts are being made to reimburse farmers who wait a few weeks to harvest, giving the young birds a chance to mature and fly away.

We were home, and we found exploring the back roads just beyond our backyard to be just as colorful and wondrous as our thousand mile journeys into the deserts and beyond. Never stop exploring, and never be trapped into thinking that you have to go vast distances to see wondrous things.

Thursday, May 9, 2019

There is Still Time to Join the Geotrippers (but not much)! British Columbia, the Channeled Scablands, the Olympic Peninsula and the North Cascades, June 26-July 10, 2019

What are you going to do this summer? Are there places in the world that you've thought of visiting but never made a plan? Maybe we can be of assistance in fulfilling your dreams! The geology and anthropology departments at Modesto Junior College will be conducting a field course dyad that will explore Washington and British Columbia on June 26-July 10, 2019. Anyone with an interest in geology or anthropology is encouraged to join us (if you want to skip the reading and get to the details, scroll down to the bottom of this post).

Our journey will begin in the Seattle area where we'll get our rental vans (yes, you'll need to find your way to Seattle). We'll then head out to the Olympic Peninsula where we'll explore Olympic National Park (including the iconic view from Hurricane Ridge, above). There will be an opportunity to explore some of the rainforest. Cape Flattery and the Makah Nation will be the anthropology focus on one day.

We'll then take the ferry across the Strait of Georgia to the city of Victoria on Vancouver Island. "Island" barely describes a landmass three hundred miles long. It has been inhabited by humans for thousands of years, and we'll be looking for petroglyphs and other archaeological evidence as we explore the south shore and then work our way north through Duncan to Nanaimo.

From Nanaimo, we'll take a ferry back to the North America mainland at Howe Sound. We will spend several days in the Vancouver area, exploring both the coastal mountains and Fraser River delta, and also the extensive museums in the city.

We'll travel the Sea to the Sky Highway, a spectacular route that leads from Vancouver to Whistler and Pemberton, site of the 2010 Winter Olympics. We'll have a chance to observe active glaciers and potentially active volcanoes, including Mt. Garibaldi and the Black Tusk.
You'll have a chance to figure out how this landscape happened...(below).
 We'll return to the United States by way of the Okanogan Valley and we'll then explore one of the strangest landscapes on Earth, the Grand Coulees and Channeled Scablands. The discovery of evidence for the incredible Spokane Floods of the ice ages is one of the great stories of geology.
We'll wrap up the trip by passing over the Cascade Range at North Cascades National Park with a stop along the potentially active Mt. Baker volcano.

This trip is just the latest of MJC’s unique collaboration of field studies in geology and anthropology, taught by anthropology professor Susan Kerr and geology professor Garry Hayes.

When and How? The group will come together in Renton, Washington (near SeaTac Airport and Seattle) on June 26 and will return to SeaTac mid-day on July 10. We will travel in rental vans, and stay in hotels.

Costs: The trip will cost $1,600, which includes transportation, admission fees, accommodations, and teaching materials. Students will be responsible for getting to and from Seattle, and for meals (many of the hotels offer free breakfasts, and some rooms will have microwaves). There will be the tuition costs for six units of semester credit, and the fees for getting or renewing a passport.

Accommodations: We are staying in a variety of motels and hotels. We are assuming double occupancy for married couples, and double to triple occupancy for singles. We will try to accommodate requests for single rooms for a surcharge, but cannot guarantee it. (The earlier your request, the better the chance for getting extra rooms).

Academics: The field courses are worth three semester units each (total of six). Participants will be expected to keep field notes and to complete worksheets and quizzes during the trip.

Contact the professors for more information (hayesg - at - or kerrs - at 

For up-to-date announcements, check out the trip Facebook page at and the MJC Geology information page at

Sunday, May 5, 2019

Tales from the Semi-Super-Bloom Tour, Part 4: Into the Realm of Demons, the Red Hills

Human mythology finds bigger meanings in everyday stories, i.e. vast battles fought in the heavens, on earth, and in the depths below pitting light against darkness, fire against ice, and good against evil. In many ways, the myths reflect the seasons, with the richness of spring and summer contrasted with the dying and death of fall and winter. That's what I was thinking about when we made a trip this week up to the Red Hills Area of Critical Environmental Concern in the Sierra Nevada foothills. The trip was another stage in our Semi-Super-Bloom Tour, our effort to visit some of the less heralded places in California where the "Super-Bloom" was not quite as spectacular (and therefore less crowded).
We had been here some weeks back, but the spring wildflowers were only just beginning to show up. And when we arrived this week, most of the flowers were already dying back and going to seed. But there was still color hanging on here and there, especially where water was still providing the gift of continued life. It reminded me of mythical legends of latter ages when the glories of the past were still remembered, but the power and majesty of said civilizations was waning, and facing climactic battles against the forces of darkness that threatened to overwhelm all.

Really...wilting flowers make me think that way...
I imagine that it is really stretching metaphors and symbolism, but these fragile flowers are truly facing a horrific test of their ability to survive. The Red Hills take their name from the serpentine soils that weather reddish brown. The soils are poor in necessary nutrients, and rich in metals and other chemicals that are toxic to most plants. Even the name of the host rock, serpentinite, recalls ghastly mythical animals like giant snakes and dragons.
And there is an additional curse: the climate. Rain falls only in the winter and spring (most years anyway), and when the rainstorms stop, they stop entirely, for six months or more. The land bakes in 90-100 degree temperatures throughout the summer and into the fall. Life struggles to exist in this harsh environment.
And yet life does persist. The flowers rush to maturity, doing everything they can to reach maturity and produce seeds before the dryness takes life away once again. And during those short weeks, the slopes are wild with beautifully colored wildflowers. The darkness and fire for a brief moment are forgotten.
The rocks themselves that make up the bedrock of the Red Hills are truly from the realms of demons and devils. The serpentine and other ultramafic (extremely rich in iron and magnesium) rocks originated deep in the underworld that exists beneath the Earth's crust, at depths of 20 miles or more (a layer called the mantle). The rocks were carried towards the surface along huge fault systems and subjected to the reactions of extremely hot chemical-rich water and intense pressure. The rocks have been sheared and twisted to the point of being unrecognizable. Although the rocks rarely contained gold, they are closely associated with the gold-bearing ores found nearby.

The Red Hills were once reviled as was befitting of an infertile barren landscape, a landscape blasted by heat and drought. Off-road vehicle trails scarred the landscape, and some locals used the area as a dumping ground or as a shooting gallery. The land was owned, but ignored, by an agency of the federal government, the Bureau of Land Management. The BLM grew out of the efforts to give lands away under the auspices of the Homestead Act in the late 1800s. The problem was that no one wanted the lands held in many areas, so the BLM eventually became the custodian of something like 250 million acres, mostly across the western United States.

As attitudes evolved regarding land-use and ecosystems, many BLM-managed lands came to be appreciated for their biological and geological values. More and more of these "abandoned" lands were transformed into more than 200 wilderness areas and nearly 30 became national monuments. The Red Hills properties were not roadless enough to be considered as wilderness, and neither the president nor Congress ever considered it for national monument status (although I don't think it would be a bad idea). Instead, when local communities began to advocate for protection of the Red Hills for their scientific and recreational values, the BLM responded by designating 7,000 or so acres as the Red Hills Area of Critical Environmental Concern. Despite the clumsy title, the designation protects the hills from off-road vehicle use, dumping, and shooting. And during the late winter and spring, tens of thousands of people will visit the site. There are minimal developments, a pit toilet, a parking area, and a series of roads and trails that provide access to much of the "park".

The explosion of vegetation in the spring attracts insects and animals. During our trip, we saw a number of birds, including California Quail and Bullock's Orioles. They added an additional splash of color to this fascinating landscape. It was an interesting day in the realm of the devils and demons of the underworld.