Monday, January 28, 2013

Glacial Polish - A Tactile Experience

A giant perpetual wave of granite, ready to crash onto the Owens Valley floor; this is the Sierra Nevada Mountain Range, a huge block of granite, a batholith, hundreds of miles long and up to 2 miles high.  

Sierra Nevada Escarpment Seen From Owens Valley   courtesy Wikipedia

Its daunting height has changed the US western interior from a Miocene grassland savanna to the desiccated rock strewn deserts of today.  This mountain wall blocks the westward march of Pacific rainstorms called the "rain shadow."   The Sierra keeps nearly all the water for itself and rarely shares. But this selfish act has a consequence …erosion by glaciers.

The Sculptor

Ted & Paula WilliansFrom tens to hundreds of thousands of years, glaciers have waxed and waned and sculpted the Sierra granite into u-shaped and hanging valleys, moraines, and polished granite.  It’s the polished granite where you can actually touch and feel the results of this process.

The process of erosion by glaciers is the grinding of granite from gravel and sand under tons of ice, like sandpaper.  A lot of rounded granite surfaces, like those in Yosemite, are appreciated from a distance; but as you get closer they look and feel relatively rough…relative to polished granite.

One of the finest places to see polished granite is near Pine Lake out of Pine Creek Canyon behind Mt Tom west of Bishop, Ca.  Elsewhere in the Sierra are small remnant crusts of shiny rock, but here you'll find whole slabs of burnished rock. 

The Hike

A number of years ago, Paula and I hiked the strenuous trail to Pine Lake.  We were nearly at the lake when we saw glistening rocks lit up by the late afternoon sun. We didn’t stop to inspect since we didn’t want to squander our efforts to reach the lake.  On our way back we allowed a few minutes to inspect the shiny slabs.  Good thing we waited; we would never have reached the lake. It was an astonishing display of polished granite  smooth enough to sit and slide onl. Our stay was short since the sun was setting and we had a long journey back. Years later we returned, this time with cameras.

 The Pix

A lapidary’s rock tumbler uses a series of smaller and smaller grit to shape rock and eventually polish to a shine.  Its incredible to think this has been done on such an enormous scale.
Just off the trail are these blocks of granite, one of hundreds that have retained smooth undulating surfaces despite being shattered by unknown forces and strewn across the hillside.

These are Chatter Marks, a series of marks made by vibratory chipping of a bedrock surface by rock fragments carried in the base of a glacier.


These images are from an iPhone.  Additional images taken with a Canon  in the near future

Monday, January 21, 2013

Mountain Gets No Respect

Some mountain peaks get no respect.  In the southern Sierra Nevada Mountains of California sits the Rodney Dangerfield of 14,000 footers.  Surprisingly it is the second highest peak in the Sierra Nevada; second only to Mt Whitney at 14,505’.
Mt Williamson stands 14,379’ above sea level.  While Mount Whitney huddles among other peaks 4 miles deep into Sierra Nevada away from the dramatic Sierra Nevada escarpment,  Mount Williamson sits right on the edge of the Owens Valley and thrusts skyward 8,000’.  

Mt Williamson is the signature peak near Independence, Ca.  It is best seen as you're driving south through the Owens Valley. For more information, check out the links below...

Thursday, January 17, 2013

Blogger of the Owens Valley

This blog will offer scientific perspectives and scientific publication links, as well as images, that relate to the Eastern High Sierra which is the southeastern section of the Sierra Nevada Mountains along US 395 in California's Inyo and Mono counties.

Living in the Owens Valley since 1971, I've observed its meteorology, seismology, and geology with fascination. There are many people who have wandered here and never left, I am one of those.  Artists, scientists, adventurists, all have found what they have been looking for in this land of contrasts.

Anthropologists will love this place as well, with its isolated culture and institutions that have survived intact through a century and a half of evolution through the timeline of the modern world.   The "Old West" is alive here if you are willing sit with your eyes closed and take in the pungent smell of ever-flowing ditch water that still irragates the ranching fields and small gardens of the Ownes Valley.

There is much to experience here, and much to learn.