Signs of Spring: The Robin Returns

After appearing in our backyard a couple weeks ago, and then disappearing during the huge snow dump of April 7th and 8th, our one robin has returned to remind us that it's spring.

The first robin is usually most noticeable in early morning becuase of the distinctive song it sings after (while? during?) getting the early worm. Typically, after a few days of hearing the song, we will finally see the robin sitting on a high perch in a nearby tree. Shortly thereafter, the first robin's many robin friends will arrive, and we will know that spring is in full swing. We are still awaiting that latter stage.

Other people, I am told, mark the true arrival of spring by the opening of the local golf course. Not I! I'm more of a robin-type of person.

A Tale of Two Trips

Looking east across the Great Salt Lake Desert toward Granite Peak from the vicinity of Dead Cedar Wash. March 3, 2010.

The first trip began early in the morning on ALT Highway 93 as I headed north toward Wendover, Nevada. The sun had barely risen, and reflections from the desert were a bright red orange.
The second trip ended with MOH and I driving past the same spot early in the evening of April 3, 2011, almost exactly 13 months later.

Silver Island Mountains and Bonneville Salt Flats. March 3, 2010.

On the first trip, I stopped at the southernmost rest stop near the Salduro siding, where an elevated viewing area provided me this view of the Silver Island Mountains north of the east and westbound lanes of I-80. The Bonneville Salt Flats were full of water when I passed by the first time; they were salty and mostly dry earlier this month, as seen in the first photo of my last post, and in the zoomed in version below.

Silver Island Mountains and Bonneville Salt Flats. April 3, 2011.

The Silver Island Mountains show some of the lower shorelines of Pleistocene Lake Bonneville: several old beaches near Silver Island Pass are highlighted by early morning shadows on the right; two wave-cut notches are almost hidden in shadow on the left. The snow-capped peaks are probably the Pilot Mountains. March 3, 2010.

The angle's a little different, but that's salt out in front of Tetzlaff Peak, the highest peak in the foreground, and maybe a bit of water or a thin mirage near the far edge of the flats. Those are the same low hills near Silver Island Pass on the right side of the photo, the same Bonneville shorelines and notches cutting the angular hillslopes as in the previous, somewhat zoomed in photo. April 3, 2011.
In March of last year, after leaving the Salduro rest stop and heading toward the SLC airport, I drove by the place where water of the Great Salt Lake was over the road in the spring following or during the El Niño of 1982-1983 (May, 1983). I thought the water looked kind of high, although I'm not well versed in its normal yearly fluctuations. I was about two and a half miles west of Burmeister and the Tooele-Grantsville exit on I-80 (MSRMaps location), looking toward the Oquirrh Mountains when I took the first picture (above) on March 3, 2010.
Strangely enough, the water once again looked high to me when we passed through early this month, and indeed it was higher: a year and one month after the first trip, spring runoff from the Wasatch Mountains (and other ranges) may have been in full swing. The second photo (above), from April 2, 2011, shows the exact same fence posts as the first, due to extreme luck and clever cropping.

For the first trip I arrived at the SLC airport and went off to Alaska. On the second trip, MOH and I arrived in Ogden and, before re-crossing the desert on our return trip, we visited a brewpub, dinosaur park, and very cool canyon.

Salt from Bonneville Salt Flats

Bonneville Salt Flats looking north toward the Silver Island Mountains and Floating Island (small and to the right).

While on our recent trip to Ogden, Utah, MOH and I stopped at the northern of two view-oriented rest stops located on I-80 near the Salduro railroad siding about 8 miles east of the Utah-Nevada border (MSRMaps location). Both rest stops provide good viewing of the Bonneville Salt Flats. From the northern rest stop parking lot you can walk out onto the flats, or at least to the edge of the flats, depending on water level or dryness.

Google Street View at northern rest stop

I didn't walk out very far, just to water's edge. A few other people were out a little farther; someone was collecting salt in large bags, probably for personal use.
A chunk of salt in its native habitat.
MOH brought a small piece of salt home, to add to our mostly unlabeled mineral collection. This is the side with the largest crystals.
Side view of same salt chunk.
View of the opposite side. One of the two sides had encrusted a surface of some kind; I'm not really sure which side was up and which was down.
Salt, more properly known as halite or NaCl, is a cubic mineral.
Cubes on top of cubes.
Tiny cubes.
More cubes.

Halite is a relatively soft mineral with a Mohs Hardness of 2½, meaning that it's barely not scratchable with your fingernail (which is also 2½), but it can be scratched by almost anything else, including a copper penny, a knife, a piece of glass, and steel. Halite tastes salty (surprise!), but not as bitter as the related potassium salt, sylvite (KCl).

Potash (mostly KCl) is mined from the Bonneville Salt Flats, as is magnesium chloride brine, which is used to produce magnesium metal and chlorine gas (for various purposes), and magnesium chloride, which is used as a dust suppressant on dirt roads and for other products.

A Few Links:
Mineral production from the Great Salt Lake

Mining and land speed records come together at Bonneville Salt Flats

View halite with a petrographic scope at Life in Plane Light

Recent Hike: A Feldspar Twin

On a not-so-recent hike, when snow had turned to mud (mud then dried and turned back to deep snow by yesterday), this small and rather unprepossessing rock caught my eye. Perhaps you're wondering why.

One side was glinting at me in the low afternoon light. I reached down and grabbed it, immediately recognizing it as a moderately sizable, though incomplete, orthoclase feldspar, one type of K-spar, with a Carlsbad twin. You can see this type of twinning in a sanidine crystal (sanidine is a related type of K-spar), and read more about K-spars at Life in Plane Light.

A view looking end on at the visible twin plane (above), and with light reflecting off the upper twin (below).

Two views with alternate twins highlighted by the sun, above and below.

I recognized this feldspar as being from nearby intrusive rocks that are often porphyrytic, and which usually contain large phenocrysts of dull pink K-feldspar like this one. Having never seen any exposures of porphyry dikes or masses on our hiking hill, I wonder if this feldspar has eroded from old alluvial fan material that formed from sources now eroded or sources farther up the main canyon than our side of the hill. Either way, it makes me want to look for unmapped porphyry.

Less Snowy Morning Views (and one Afternoon View)

At least two limestone formations and at least one shale without any moon: taken before 7:00 am on March 27th at nearly the same time as the moon picture from five days prior (here).

The just-past-quarter moon as seen farther east in the sky that same morning.

One of my views on the way home from work, with a snowy hill of Tertiary ash-flow tuff on the right and the cyclothemic Pennsylvanian Ely Limestone on the hill behind that. The dark hill on the left, above the Ely Limestone and beneath the dark clouds, is underlain by the garnet-bearing rhyolite of Garnet Hill. March 27th.

Alpine glow on Ward Mountain, March 28th.

I see this truck every morning on the way to work. It hasn't moved in more than three years, unless it moved when I wasn't looking and returned to the same spot. The ice was everywhere that week early in the morning, melting most days to rampant mud. March 28th.

March 29th: a day of no pictures; a day with snow that fell like rain, slanting northward from the southerly wind; a dreary day that at 30 to 34 degrees Fahrenheit felt colder than the chill of all the 20 degree mornings of the several previous sunny or semi-sunny days; a yucky, mucky day.

Two photos of the sunrise the morning of March 30th, above and below.

The last sliver of the waning moon playing peekaboo behind the clouds. Color has been somewhat intensified or weirdicated during enlargement and addition of contrast to make the moon more visible.

The robins have been back for about a week: spring is here!