Spring is Coming, and Flowers are Awakening in the Sierra Nevada Mother Lode

It's still a bit early to see the awesomeness to come, but the spring wildflowers are beginning to make a splash of color in the Sierra Mother Lode. With the record and near record amounts of rain in Northern California, the slopes are primed to produce a wildflower show to compete with the "super-blooms" taking place in the California deserts this year. We were exploring a portion of the southern Mother Lode in the vicinity of Mariposa and Coulterville yesterday, and I took my attention off the rocks for a few moments to catch some pictures of the early-blooming flowers. Above is a Fiddleneck (Amsinckia species), often one of the first of the wildflowers to bloom in this region. It can be poisonous to livestock, and yet was used as a food and medicine source by Native Americans.

Near the Pinetree-Josephine Mine we saw a number of Brodiaea, or Blue Dicks (Dichelostemma capitatum). These beautiful flowers grow from bulbs that were also an important source of food to the Native Americans of this region.

I don't know as many wildflower species as I should, as much as I appreciate their beauty. In a few places there were carpets of small yellow flowers (Goldfields, in the Lasthenia genus, thanks to Siera Nystrom in the comments).

Seeing some of the flowers growing in the usually poisonous serpentine soils reminded me that it is time to head up to the Red Hills soon, a Mother Lode locality known for a large number of endemic species.

As per Jane Strong in the comments, Orobanche fasciculata, clustered broomrape. Thanks for the identification!

And finally, the ever-present and always beautiful Indian Paintbrush (Castilleja species). There are some 200 species of this flower.

This is only the very beginning of what promises to be a wonderful year for wildflowers. I hope to be bringing many more such scenes to your attention in coming weeks!

Where the Sierra Nevada Rises From the Sea: The Granitic Rocks of Garrapata State Park

We've reached the next beach on our exploration of the most beautiful coastline in the world, the one extending from Big Sur to Bodega Bay in Central California (register your arguments in the comments about your own interpretation of "most beautiful"!). It's called Garrapata State Park, and it offers some nice shorelines carved into the granitic rock of the Salinian Block, the displaced terrane of Sierra Nevada rocks that now forms a mountain range sloping directly into the sea.

Garrapata doesn't quite have the prominence of Julia Pfeiffer Burns State Park, or Point Lobos. There are no visitor centers and no campgrounds, and in fact, few tourist facilities at any kind. No parking lots or admission booths. Just a table or two and some fine trails. It is pretty much a wilderness park, aside from the intrusion of Highway 1.

The coastal terrace at Garrapata was covered in wildflowers despite the late season when we visited. Above we can see an Indian Paintbrush. I'd try to identify it, wondering if it was the rare Monterey variety, but became aware that with more than 200 species, I probably wouldn't be successful at nailing it down.

The rocky coastline reveals some of the best exposures of the granitic rocks of the Salinian Block. I use the term 'granitic' because the petrologists who study igneous rocks are rather specific when they classify the light colored grainy plutonic rocks that normal people call 'granite'. The proportions of the minerals that make up the rock (quartz, orthoclase feldspar, plagioclase feldspar) determine whether the rock is granite, granodiorite, tonalite, diorite and others. On this part of the coast, the rock is identified as the porphyritic granodiorite of Monterey. Granodiorite contains a higher proportion of plagioclase than granite has. The term 'porphyritic' means that the rock contains much larger crystals of feldspar in a finer matrix of other crystals,

The rock formed as molten plutons deep in the crust. The rocks cooled slowly over thousands of years, allowing the crystals to grow to visible size. The granitic rock is monolithic while it remains at depth, but when it is exposed by erosion, the release of pressure allows the rock to expand. It does, but not like a marshmallow. It breaks into vertical and horizontal fractures called joints.

Ocean waves do a great job of exploiting the joints and fissures, tearing the rocks up and producing rugged sea cliffs and offshore rock islands called sea stacks.When waves impact against the rocks, they can exert pressure on the order of several tons per square foot, and air is compressed in fractures to the same degree.

Waves can widen joint systems, forming sea caves, like those seen below.. I don't know how far the caves at Garrapata extend, but some on the north coast are hundreds of feet long, and navigable by kayak.

The kid in me wants so badly to explore caves like these. I don't think the California coast had much of a history with pirates, but I could imagine treasures being hidden in the backs of some of these caves.

Garrapata State Park also exposes an excellent example of a nonconformity. Unconformities of all kinds are buried surfaces where erosion once took place. A nonconformity develops when plutonic or metamorphic rocks are exposed at the Earth's surface by erosion. Later, the surface was covered with sediments, in this case conglomerate deposited by streams flowing across the coastal terrace. Wave erosion later exposed the relationship seen in the photo below.

Terraces are not especially common along the Big Sur coast, but a modest one can be explored at Garrapata. Terraces result when the back and forth of wave action on a beach forms a more or less horizontal wave-cut bench. If sea level falls or the land rises, the bench is lifted above the wave zone to form a flat surface surrounded by coastal cliffs leading down to the water below. The terrace was covered with colorful vegetation due to the stable deep soils.

It isn't maybe fully recognized by most tourists, but every sea stack and small island on the California coast is part of California Coastal National Monument, established in 2000 by presidential proclamation. There are around 20,000 such rocks along the 1,100 miles of the California shoreline!

Our last little discovery of the day was a small waterfall that developed where Soberanes Creek flows across the coastal terrace and trickles into small cove. It was a colorful intersection of rock, water, and life.

Next stop: the point of the sea wolves!

Addendum: one of my Facebook friends pointed out what a terrible name Garrapata actually is: Tick. It reminds me of Avenida de Las Pulgas near Menlo Park in the Bay Area: the Avenue of the Fleas. It's really true: all place names sound better in Spanish!

Three Roads Diverged...but why? Because there's a huge landslide, that's why...

It didn't take Ron Schott long to reveal why three roads diverged in the wood, the subject of yesterday's post on Highway 41 heading into Yosemite National Park. The Ferguson Slide was a problem child for CalTrans and road management crews for many years. The orientation of the river and the dip of the metamorphic rocks on the high ridge conspired with the undercutting effect of roadbuilding to destabilize the slope above the highway (you can see some of the slide activity in this video). The slide permanently covered the highway, and the first temporary bridge did not allow larger vehicles to make the 90 degree turn. Bus tours are the life-blood of the local economy, so the current bridge crosses the river at an angle so longer vehicles can cross safely. I blogged about the slide last year, when I compared the Ferguson slide to a different kind of mass wasting event just inside the park boundaries.

The fix is still temporary, with only a single lane available, so delays are common while cars wait at both ends. A more permanent solution is the subject of extensive studies, which can be reviewed here.

We had to wait at the slide both coming and going home from Yosemite yesterday, so I was able to hop out and photograph a couple of the emerging springtime wildflowers. It was cold and dreary, so most flowers weren't doing much (it had actually snowed the previous day), but a few Indian Paintbrush flowers were visible, and the redbuds were spectacular all up and down the Merced River Canyon. I really want to head back up in the next week or so, and see the poppies and fiddlenecks mantling the high slopes.

But, you ask, how was Yosemite? Spectacular in a different way. Coming up in a future post!

A Convergence of Wonders: Day 2, Lava Beds and Newberry Caldera

A Convergence of Wonders is a chronicle of our recent journey through the Pacific Northwest and Northern Rocky Mountains. This the second day's story...

What is that blazing orange light interrupting my slumber?? June 16 dawned very early, with twilight beginning around 4:30 AM, and sunrise about 5:20. I was up for good at that point. There was no sleeping in the brightness; tents don't insulate you from the outdoors as well as solid walls. I've always loved dawn at Lava Beds National Monument, though. The sky is as big there as any place I know, with far-off horizons and clear air.

Our day was going to be spent on the two largest volcanoes of the Cascades, and hardly anyone has heard of either of them: Medicine Lake Highland, and Newberry Caldera. Crater Lake was slated to be on the day's menu, but 10-12 feet of snow still coated the rim, and we just weren't going to see it this time around. Both Medicine Lake and Newberry have been called basaltic shield volcanoes, but they are more complicated than "normal" shields with a variety of lava and magma compositions and are described as "shield-shaped volcanoes". We started the day on the flank of Medicine Lake Highland, but we couldn't actually see the volcano until mid-day, when we were far enough away. It is the largest single volcano in the Cascades with a volume of around 130 cubic miles (Shasta has around 85-100 cubic miles).

The best known part of Medicine Lake Highland is Lava Beds National Monument, where we spent the night. The park preserves a series of basalt flows that developed a network of lava tubes, underground conduits that allowed the basaltic lavas to flow for miles before cooling. The tubes drained at the end of the eruption, leaving a series of caves. Lava Beds preserves the largest concentration of lava tubes in North America, in excess of 700, with a combined length of more than 30 miles.

The students had explored a few of the lava tubes the previous night, so we sampled just two in the morning. Valentine Cave is in a separate younger flow, and is remarkably clear of debris and easy to walk through (the CCC cleared much of the talus in the 1930s). It has most of the interesting cave features such as lavacicles, bathtub rings (lava benches), rafted boulders, lava falls, and pahoehoe flows on the cave floor.

Outside the caves, there were an unusual number of wildflowers in evidence, given the long spring and cooler temperatures. This is an Indian Paintbrush on the flank of Mammoth Crater, the source for more than two-thirds of the lava flows in Lava Beds.

After a visit to the Visitor Center, where we were certified as free of white nose syndrome (this is a horrific bat disease, not a human one), we went to the more ominous sounding Skull Cave. The name is like something out of a campy adventure movie, and the reality is also kind of frightening. Skull is a cave with multiple levels, and the first drop to the second level down is just within the zone of total darkness. Animals and a few humans without sources of light would move into the cave, looking for water maybe, and just as it got dark they would step over the side into the abyss (literally and figuratively). Today there is a metal stairway to negotiate the dropoff, and we explored the icy depths (literally icy; water sinks into the cave in the winter, freezes, and stays there, even in summer).

Skull has the largest opening of any cave in the park because it is part of the main feeder tube that transported the lava for 10-15 miles. Unlike the smaller caves, the main tube is relatively unstable, and huge blocks of basalt have broken off the ceiling and littered the cave floor to the extent that few original flow features are visible. It was so large I half-expected to see Han Solo, the Millenium Falcon, and a giant space worm in there.

Our next stop was more sobering. California was never kind to the hundreds of native cultures that existed prior to the Mission era and the Gold Rush. Many were slaughtered or sickened to extinction without leaving any kind of record. The Modoc culture was destroyed, but not without a fight. Lava Beds was the site of the last battles between the U.S. military and native peoples in California, in 1872-1873. Despite being outnumbered as much as 10-1, the Modoc people held out for five months.

I've provided a detailed commentary on the battles that took place in my Other California series about Lava Beds. In short, the Modocs held the advantage of knowing the territory, and of taking shelter at Captain Jack's Stronghold, a natural fortress that was almost impossible to take as long as there were a few armed defenders. Pressure ridges and schollendomes provided the trenchs and "castle" walls that made the stronghold practically impregnable.

A fire swept through the Stronghold and much of the northern part of Lava Beds a few years ago, leaving just a few Junipers unscathed. Being the only trees for some distance, a lot of birds were in evidence, including a pair of juvenile Great Horned Owls.

Why do owls always look so perturbed? I suppose a bunch of tourists with cameras had something to do with it...

We moved on to an outlier of the park, a deeply eroded tuffaceous cone called Petroglyph Point. The cone had erupted in the midst of Tule Lake, and the yellow layers of tuff had been deeply eroded by waves on the lake, forming a striking west-facing cliff punctuated by tafoni, hollows formed by weathering. One can see the wave-cut notches running along the base of the cliff behind the chain-link fences. Why are the fences there? Oh yeah, petroglyphs. Petroglyph Point is the largest panel of petroglyphs in the country...

Most of the rock carvings in the cliff predate the Modocs. The lake lapped at the base of the cliff, and the artists would have required rafts or canoes to reach the site. Because the lake has been mostly diverted and dried up for agricultural purposes, blowing sand and dust threatens the integrity of the rock art. See more info on the panel here.

We were finally far enough away to see the full extent of the Cascade's largest volcano, by volume. Medicine Lake Highland is the broad gently sloping dome on the horizon. Mt. Shasta can be seen on the right skyline (click on the photo for an enlarged view).

Then came one of the dreaded "pushes". We had to put about 170 miles between us and our next destination, Newberry Volcano. Oregon has some pretty volcanoes, including Mt. Theilsen and Mt. McLaughlin, but they were only occasionally visible between stretches of dense forest. The road was very straight and monotonous after Klamath Lake. Eventually though, we arrived at Newberry Caldera, a shield-like volcano similar in many respects to Medicine Lake Highland. We also found a wall of snow. The bathrooms were unavailable, the camp we had reserved months earlier was not open yet (fortunately I knew this and had made alternate arrangements), and there was no official parking available to see our main site, the obsidian dome. We made do, and most of the students hoofed it over the snowbanks to see the obsidian up close (more than a few snowballs were launched as well).

I crossed the highway and climbed the hill to get a better perspective on the dome. Mountains like Newberry and Medicine Lake have multiple magma sources, probably because very hot deep mantle source basalts melt some of the more silica-rich continental crust. The volcanoes spew out plenty of highly fluid basalt flows, but also occasionally produce much stickier rhyolite flows, forming small plug domes. The rhyolite lava often forms obsidian and pumice, as it did here.

We were in the midst of a caldera on the summit of Newberry. A caldera forms from the collapse of the top of a volcano due to the withdrawal of magma during eruption sequences. Paulina Peaks on the rim of the caldera loomed high above us while we hiked through the snow. Crater Lake (which we were not able to visit) is one of the world's best examples of a recently formed caldera. The catastrophic explosion that accompanied Crater Lake's origin probably did not happen at Newberry. The caldera development was more gradual and less explosive.

We were ready to get to camp, and traveled the final 30 miles as quickly as we could. We set up in the group site at Tumalo State Park, a pleasant site just outside Bend, Oregon. The evening was nice enough, but somehow overnight, the temperature dropped to 28 degrees. This is summer??

On day three, we head for the coast and for great disappointment (this sentence has multiple meanings, as you will see).