A Fool for Fiddlenecks and Lover of Lupines

Not very geological, I suppose, but sometimes my travels and interests spill over into the biological realm. Part of the fun of springtime in the Sierra Nevada is the profusion of flowers that emerge for a couple of weeks. It doesn't take long before they dry out and lay down seed for next year, but the geography keeps the show going all summer. The Sierra mountain block rises gently to the east, and as conditions dry out in the foothills, the snow is only starting to melt in the high country. There are flowers to be seen somewhere in the mountains all summer long.

One of my early-season favorites are the Fiddlenecks in the genus Amsinckia, a small flower that blooms especially well along roadsides and disturbed surfaces in the foothills. There are around a dozen species across the American West. They're poisonous to livestock and considered a weed by some, but parts of some species were utilized by Native Americans for food and medicinal purposes. One of my other favorites is the Lupine (genus Lupinus), which grows at many elevations in the Sierra, and for that matter throughout much of the world (there are hundreds of species). Like the Fiddlenecks, it is poisonous to cattle and can sometimes be considered a noxious weed. On the other hand, some species produce a nutritious edible seed and are considered an alternative to soy beans. They also fix nitrogen in the soil, allowing other species to colonize.

The other pretty flower I noticed in this early part of the spring bloom was the one below, but I don't know what it is. Any of my flower-expert readers gonna tell me? Some kind of Brodiaea?

The Other California: Spring Arrives in the Prairie Lands

California has a rather sullied reputation these days; a lingering depression (at least in our Central Valley), high unemployment, urban nightmares, Hollywood, and a legislature that lacks the will to support the education of its children and young adults. And yet, 38 million people choose to live here. They have a lot of reasons, and some think they want to leave, but frankly California is a nice place to live. Especially if you have any interest whatsoever in geology. There is hardly any place in the world that packs so much geographic variety within its borders: coastlines, mountains ranges, deserts, and valleys. My Other California series is an on-again, off-again exploration of the geologically interesting areas that don't normally show up on our tourist postcards. I started this series with an exploration of the prairie lands of California that surround the state's vast Central Valley. Because I live on the fringe of these prairies, I venture out some afternoons to see what's happening. Friday was an exploration of Merced Falls Road in the Sierra Foothills, a short drive that included a surprise vista of Yosemite's Half Dome and Clouds Rest.

Merced Falls Road connects Highway 59 at Merced Falls to Highway 132 near Don Pedro Reservoir. It provides access to a number of ranches and the recreational areas along McClure Lake. It also includes numerous exposures of the metamorphosed sediments and volcanic rocks of a Jurassic island arc system that was slammed (in a geologic sense) into the west coast of the North American continent in late Mesozoic time. The rocks have been upended and deeply eroded, producing a landscape that looks like a neglected cemetery (the outcrops look like tombstones). The rocks include the Mariposa formation and the Gopher Ridge volcanics.

Friday was a fine day for seeing the early blooms of what promises to be a fine wildflower season. More on that in the next post. When we reached the little village of La Grange downstream on the Tuolumne River, we could see the preparations being made for an exceptional spring runoff. The snowpack in Yosemite is somewhere around 150-160% of normal after three years of drought, and the water authorities are emptying out Don Pedro Reservoir to make room for the much needed onslaught of snowmelt that begins soon. Below is the artificially induced mild flood being conducted to avoid an out-of-control flood in a few weeks.

What else did I discover? I found out my hay fever is alive and well...sniff...

A New Spot (for me, at least) to see Half Dome from the Central Valley

Half Dome is one of the iconic peaks that surrounds Yosemite Valley, and is photographed millions of times every year. Although it is a prominent landmark from the floor of Yosemite Valley (it looms more than 4,000 feet above the valley), it can fade to an insignificant knob in a larger view that encompassess the Sierra Nevada crest that reaches another 5,000 feet higher.

As such, it has been a minor controversy about whether Half Dome can be seen from the floor of the Central Valley. The Yosemite Blog raised the issue a while back, and it seemed more or less settled that it could be seen from the valley floor along a narrow strip of land that runs through the Denair area. I caught a picture of my own from a spot near the corner of Keyes Road and Hickman Road north of Turlock in November of 2009 (it's at the bottom of this post). Just the same, I still see the occasional skeptic on the Internet who insists that all the pictures are photoshop fakes (as if I had any such skill...).

I was out and about today and found a new spot to view Half Dome from the floor of the Central Valley. I wasn't sure at first, but I took a highly zoomed shot, and checked it against a picture I took from above Bagby Grade on Highway 49 along the same visual line. If you compare the two, you can see the prominent peak of Clouds Rest on the skyline left of center, and the shadowed triangular face of Half Dome on the right.

If you want to see the same spot, you need to get to Turlock Road (County Road J17) between Oakdale Road and Highway 59 at the little village of Hopeton. You'll need a clear day! As noted above, this is the view from Keyes Road that I took a few years ago. The higher peaks behind were obscured at the time by some distant storm clouds (the whole sky was overcast, even though it appears blue in the photo).

Postscript: I just realized I posted this on April Fool's Day, but it isn't a prank! To see what kinds of things I do for April 1, check this, this, and this...

What Does An Urban Small Stream Flood Advisory Flood Look Like?

It looks kind of like this....

Dry Creek has its headwaters in the foothills of the Sierra Nevada north of Modesto Reservoir. It flows southwest through the farmlands into the town of Modesto, where it joins the Tuolumne River. Dry Creek, despite its name, is rarely dry. Prior to agricultural development in the last century it was indeed dry for much of the year, but since the irrigation began, seepage keeps water in the creek for most of the year. But rarely is there more than a few cubic feet per second.

Dry Creek is an unregulated drainage, meaning there are no dams or other measures to control floodwaters. It normally isn't a problem, but every couple of years events conspire to cause problems. This week was one of those weeks. The ground is saturated from weeks of above-normal precipitation, and we had a violent wet storm yesterday that dropped several inches of rain and hail in the foothills.

The creek won't stay high for long, but for a few hours today, the flow was over 3,000 cubic feet per second. By comparison, the usually much larger Tuolumne River (with the headwaters many miles away at the Sierra Nevada crest) is at flood stage at 9,000 cubic feet per second. With this discharge, some properties in downtown Modesto may be flooded. Pretty big numbers for a little podunk gully. I would have shown "before/after" pictures, but I never think of taking pictures of the creek when there is no flooding going on.

Stream data comes from NOAA, found here.

Giant California Earthquakes and the Radiation Cloud; California Falls into the Sea: Geotripper Emerges from the Apocalypse...

Welcome, survivors of the Apocalypse! Like you, I have been hiding in my underground bunker, safe from the radiation cloud and protected from the supermoon and giant earthquake that caused California to plunge into the sea. I'm waiting to see if my investment in oceanfront property on the Carrizo Plains has paid off with a nice seaside view. Did any of the southern California mountains remain as offshore islands? I was sort of hoping to have a few on the horizon. I've been rationing my cheetos, pringles and beef jerky. I lined my bunker with lots and lots of tin foil to protect myself from the electronic emanations of those pointy-headed "scientists" who kept poo-pooing the predictions of those who sensed the coming Apocalypse in their minds and mathematical calculations. As soon as I saw the work of the prophets on the Internet I knew it had to be true. Their prophecies were aired by the cable news networks, so I double-knew it had to be true. I didn't feel the earthquake because I built my shelter on a spring-loaded foundation. Was it really shaky? My clock broke, so I've been estimating the number of days I've been in hiding by making chalk marks on the wall; it's 2012 isn't it? The Mayan calendar came to an end and all? Have the Zombies died out yet?

Well, that's that. The supermoon weekend passed and California is still here. The full moon didn't scrape along the ground and erase cities. There were no tidal disruptions. There was no earthquake. There were no volcanic eruptions. No one melted from the radiation cloud. The prophets and predictors were wrong, yet again, wrong again for the umpteenth time. Over and over they are wrong. Hundreds of times they have been wrong. And still they find a stage on the cable news networks, the Internet, the radio...over and over. There always seems to be a crowd of uninformed and misinformed people who take them seriously, and there are uninformed and misinformed news readers who are unable to critically assess their irresponsible claims. At the same time they dismiss the statements and findings of academics who have given over their lives to the study and understanding of the earth sciences. And in the end the charlatans and fakes are never brought to account for scaring people and causing economic disruptions.

I've seen enough of "judgment journalism" in politics to know that cable news outlets are capable of shaming those who cross the line of honesty and decency. They are capable of using their media platform to upbraid and criticize officials who steal money or engage in hypocritical behaviour. Why are they not criticizing and shaming those who carelessly predicted earthquakes and radiation poisoning without regard to the consequences of being totally (and predictably) wrong? I have never seen the news readers take a self-proclaimed "psychic" to task for their hundreds of wrong predictions.

Wouldn't it be nice just once to see a camera crew waiting outside the home of one of those self-proclaimed psychics or would-be earthquake prophets and ask them over and over why they made yet another wrong claim that needlessly scared people? Just once to hear them told to their face that they are charlatans and fakes? How long will the con artists persist when they know they will be subjected to public derision when they make their spurious claims?

In the meantime, the media outlets need to learn the real facts about the possibilities of quakes and other hazards in California (and anywhere else) and make sure their audiences know the actual magnitude of the threat. The faults are here after all, and there is a lot of built-up stress. Damaging quakes will happen, and we need to all be as prepared as possible. The first thing to do is to arm yourself with knowledge. Get this knowledge from responsible government agencies like the U.S. Geological Survey, or the California Geological Survey, or academic organizations like the Southern California Earthquake Center. Then you make the appropriate preparations: keep emergency supplies of water, flashlights, radios, batteries, and first aid kits, both in your home, and in your car. Have a family plan for what to do when disaster strikes.

By the way, it is ok to have pringles and cheetos in your emergency supplies...but put some healthy stuff in there too. There is junk food and there is junk news. Too much of either can be harmful to your health.

A Day in the Field...Day Backwards On Fun Having, Part Three. Stanislaus Table Mountain from above

The conclusion of my backwards mini-series on the Stanislaus Table Mountain starts with an earlier trip that will serve to explain the origin of the backwards geology of our hiking destination from last weekend (parts one and two here and here). The picture above reveals our path from a slightly different point of view, mainly from several thousand feet above. Back in 2002, the father of one of my students called me early one morning and said "Let's fly my plane. Where do you want to go?" I immediately thought of Table Mountain, because it is best seen and appreciated from the air.

I've been saying "backwards" a lot in these posts, but the actual term we want to use here is "inverted", as in "inverted stream". Our hike was to the top of a lava flow that sits hundreds of feet above the surrounding landscape. On first glance, this may not seem to make much sense. The key to understanding this oddity is to realize that the lava flow did not start out on top of a ridge.

Around 6 to 20 million years ago, volcanic activity was producing ash and lava flows in the summit region of the growing Sierra Nevada in the vicinity of Sonora Pass and the Dardanelles. The earliest volcanic activity included violent explosions of light colored rhyolite ash that coated the Sierra foothills (the Valley Springs Formation), but later eruptions mixed with water and snow to form volcanic mudflows (called lahars). These mudflows and river deposits coated the foothills region hundreds of feet deep, a series of layers called the Mehrten Formation. In the picture above, the layers form contours on the sides of the hills. For those familiar with the Knights Ferry area, the Mehrten forms the cliffs of Lovers Leap.

In the midst of this activity, about 10 million years ago, a single flow of latite (a sort of orthoclase bearing andesite) traveled more than forty miles down the western slope of the rising mountain range. Having flowed far beyond any volcanic slopes, the lava followed a riverbed, an ancestral path of the Stanislaus River. The picture below reveals the winding path the lava followed (our hike was located right in the center of the photograph). The surrounding rock was easier to erode than the latite, so when the mountains continued to rise, the lava flow remained while the other rocks were carried away. The bottom of the river became the top of the ridge: a textbook example of an inverted stream.

Farther "downstream" the lava flow widened considerably, forming a more plateau-like landscape. The Stanislaus River ended up carving through and around the lava flows. Some of the steep gorges became idea sites for modern-day reservoirs, like New Melones and Tulloch, seen below. The Table Mountain lava flow disappears beneath the slopes around Knights Ferry.

I mentioned in the previous post looking over towards the Harvard Mine from the summit ridge of Table Mountain. The open-pit mine was active from 1986 to 1994, producing about 660,000 ounces of gold from about 17 million short tons of rock. The lake in the pit is about 300 feet deep. Just prior to closing down, the miners recovered a huge mass of crystallized gold, weighing more than 40 pounds. The gold is on display at the Ironstone Winery in Murphys.

It was a lot of rock that was removed and piled up to get at the gold. So not only is the local landscape inverted, it has also been turned inside out.

I hope you've enjoyed these vignettes of my pair of journeys to a backwards landscape! The flight was made possible by Ken Iwahashi of KKI Corporation in Modesto. I have a web page with additional pictures and descriptions of the flight at Geotripperimages.com.

For more on the volcanism of the Central Sierra Nevada, check out:

Busby, C.J., et al., 2008, The ancestral Cascades arc: Cenozoic evolution of the central Sierra Nevada (California) and the birth of the new plate boundary, in Wright, J.E., and Shervais, J.W., eds., Ophiolites, Arcs, and Batholiths: A Tribute to Cliff Hopson: Geological Society of America Special Paper 438, p. 331-378.

A Day in the Field...Day Backwards On Fun Having, Part Two

Continuing our previous blog entry about exploring part of the California Mother Lode, we reach the summit of Table Mountain, near New Melones Reservoir. We had made our way across some grassy meadows and oak woodlands, and then climbed up a steep talus slope through brushy thickets to reach the edge of the summit. We walked into a strange forbidding landscape. The summit of Table Mountain at first looked barren and practically lifeless, but it took only a moment to realize it was full of life, especially on this particularly strange day of rain and storms.

I walked quickly over to the other side of the ridge and looked down on Highway 108 and the Jamestown area, including the mothballed Harvard Gold Mine. The ridge is long (miles long) and winding, and flat. But it is only a few hundred feet wide in most places. Boulders of lava were scattered all across the surface. The 'backwards' theme of these post has the most to do with the strange location of the lava flow at the top of the ridge. I'm going to fully explain that in the next post, but first I wanted to mention something outside my expertise: the biology...

As I wandered across the summit plateau, I realized that something was missing: fields of waving grass. It was striking. In the meadows below, exotic grasses were growing profusely everywhere. Up on top, grass was present, but as can be seen below, it is dominated by other plants; especially small flowers and mosses. Clearly the soils were very thin due to the nature of the lava, but these non-grass plant species were doing just fine, from the looks of things.

From what I could understand from some of the environmental studies of the volcanic tablelands, the exotic grasses have never really established themselves on the plateau the way they have in the pasture lands and meadows below. It's too tough of an environment. Apparently, most of the plants up here are natives.

It is a mostly dry and hot environment for much of the year, but for a few weeks or months, rain fills a number of low areas called vernal swales, which provide a unique growing environment for endemic species. Invasive exotic species cannot tolerate the extreme conditions. The vernal swales are broadly similar to the vernal pools found on the floor of the Central Valley (in the few undeveloped areas), but are more rocky with less clay. I saw quite a few unfamiliar flower species.

As I got closer (to the ground, that is), more and more species of plants appeared. I had to step carefully, ponds were everywhere! Most of the flowers were very small, reminding me of the toy flowers a child might use to decorate the outside of dollhouse. A garden of miniatures....

The colors were vivid, despite the grayness of the skies. Actually, as I looked around the skies were not just gray, but threatening. Rain was falling all around us, and a bitter cold wind was sweeping across the summit plateau. I wasn't quite ready to retreat just yet.

I got on my hands and knees and realized I was looking at an entire ecosystem on the surface of a single boulder (below). It was an incredibly colorful palette of living things, and a wonderful confluence of geology and biology.

I generally don't make a practice of quoting long passages of someone else's work if I can do a decent job of paraphrasing. but I'm not much of a biologist, and I have a feeling some of my biology-loving readers might want some of this info. It was buried deep in an environmental impact report by the Bureau of Reclamation about the Table Mountain flora and vernal swales (found here, starting at page 4-29):

"Vernal pools are an ephemeral wetland vegetative community with predominantly low-growing, ephemeral herbs. Germination and early growth occur in winter and early spring, often while plants are submerged, and pools dry out by summer. Flowering is often in bands at the margins of the pools. This community type occurs in shallow depressions, ranging from a few meters to tens of meters in diameter. Characteristic plant species found in vernal pools are Pacific foxtail (Alopecurus saccatus), common blennosperma (Blennosperma nanum), Cleveland’s shooting star (Dodecatheon clevelandii var. patulum), toothed downingia (Downingia cuspidata), spinysepaled button-celery (Eryngium spinosepalum), hedge-hyssop (Gratiola ebracteata), Fremont’s goldfields (Lasthenia fremontii), Douglas’ meadowfoam (Limnanthus douglasii var. rosea), white-headed navarretia (Navarretia leucocephala ssp. leucocephala), adobe popcorn flower(Plagiobothrys acanthocarpus), miniature popcorn flower (Plagiobothrys stipitatus var. micranthus), Sacramento pogogyne (Pogogyne zizyphoroides), Delta woolly marbles(Psilocarphus brivissimus var. multiflorus), greater duckmeat (Spirodela polyrrhiza), and Wildenov’s clover (Trifolium willdenovii) (Stone et al. 1993 in Reclamation 1995). Special status plant species that may grow in the planning area vernal pools include Sacramento orcutt grass (Orcuttia viscida), slender orcutt grass (Orcuttia tenuis), Bogg’s Lake hedge-hyssop(Gratiola hetersepala), and legenere (Legenere limosa).

Within the planning area, intermittently-formed pools appear after rainfall or snowmelt on top of Table Mountain between 1,200 feet in elevation in the south and 2,600 feet in the north. Although these pools share some of the characteristics of some vernal pools in the Central Valley, they are not true vernal pools in that they do not have a clay underlayer that prevents percolation. Instead, they form in swales in the rocky surface of Table Mountain. The soil is poorly drained and the parent material on Table Mountain is a Pliocene lava flow (andesite). Intermittent pools occur on Table Mountain in seasonally wet to saturated rocky meadows that have slight soil development (Evens et al. 2004). They are interspersed within the annual grassland (Reclamation 2006b). Intermittent pools at Table Mountain do not support the range of species found in vernal pools in the Central Valley, possibly due to differences in substrate(primarily shallow, rocky substrate versus clay substrate in valley vernal pools). Although vernal pool habitats are very delicate and easily disturbed in general, this is even more pronounced on Table Mountain where soils are poor, shallow, and loose.

To date, vernal pools have resisted invasion by exotic plant species, probably due to their ephemeral nature (USACE 1997). However, the scientific community is concerned that exotic plants may colonize vernal pool communities, possibly displacing the highly specialized native vernal pool species (USACE 1997). Despite these concerns, there is no supporting evidence that this change is occurring in vernal swales found on Table Mountain (USACE 1997).

So much of the time I am showing people a place that is new to them. It is always fun to show someone the treasures that exist practically in their own backyards. On this hike, I got that experience of seeing a place for the first time. I loved every moment!

In the final post of this mini-series, I will take a look at Table Mountain from a slightly different point of view...