Sunday, March 06, 2011

Soda Lake

Saturday morning, I went on my second Master Naturalist trip with the folks from Sibley Nature Center.  This week's trip was a short one, just a dozen or so miles south of Midland to an SWD (Salt Water Disposal) facility.  We all parked there and headed out into the cold, windy morning.  Cold out here is about 45 F, by the way.
Some of the crew.

Our mission today, just like last week at Tahoka Lake, was to poke around.  We looked for plants and animals.  If we didn't know what something was, we asked Burr.  We also got some more geology lectures.  Always good review for me.

The salt lake we visited was all dried up.  The last of the water went around Christmastime.  The surface we walked on was a little damp (atmosphere-derived), with powdery silt underneath.  Burr et al. referred to this material as loess, indicating deposition via wind action.  It was powdery and fluffy in a strange way.  Everyone left distinct footprints.  Riding along with me was a cross-country cyclist, Jaden, who was staying at my house for a day.  He was wearing the 5-toed shoes that make prints like bare feet.

Walking across the fluffy silt.

Soda lake bottom

What made the sediment fluffy?  The photo above provides some clues.  The snake-looking tubes are areas where the sediment was actually pushed together.  This appears to be due to frost heaving.  To the left you can see the more typical dessication mud cracks.

Salt Cedar

One of the first plants we found was the much-maligned Salt Cedar.  This was imported as an ornamental plant and has taken over many drainages in the desert southwest.  Apparently it chokes the waterways and is generally undesirable.  Chemical eradication has been attempted on the lower Pecos in Texas, with much success (so said Burr).  In other areas, including the Big Bend, a type of beetle that feeds on Salt Cedar leaves has been released.  This is expected to control the Salt Cedar population, but apparently is also affecting similar local species.

Salt Grass.

This salt grass apparently occurs on several continents, in similar alkali environments.  How did it spread?  Why didn't other species (like Salt Cedar) spread too?

Loess bluffs

Along the downwind side of the lake are 10-15' high loess bluffs.  In some areas these have been carved by native peoples to make shelters.  In this photo, you can see several types of plant life common in the area.  The green bush in the center is creosote.  Crush the little leaves and you get the smell of rain in the desert.  I wonder what chemical that is.  Atop the bluff are some mesquite bushes.  The short, stubby-looking bushes are varieties of ephedra, aka popotillo or "Mormon tea".

The class spent an hour or so walking along the base of the loess cliffs, where there were many interesting animal holes, droppings, insects, etc.  Several members of the class got very excited when they found some mediocre (in the grand scheme) gypsum crystals.  Gypsum (hydrated calcium sulfate) forms as an evaporate mineral in this lake bed, and anywhere where water is allowed to pool and then evaporate.

I found a few critters in this area, including a lizard.  I don't know what type of lizard it is, except skittish.  I got this photo by holding my camera out in front of me and pointing it back at the cliff face where the lizard was hiding from me.  

This "Robber fly" might not be a remarkable find, but on this day at Soda Lake you couldn't be picky.  There weren't many critters out and about:

Robber fly

I continue to practice my macro photography, but depth of field on this one is poor, even at f22.  I think I need to investigate a better macro setup.  My mom takes amazing close-up photos with a slightly older Canon point-and-shoot.  Visit her blog, Plants Amaze Me, to see some of her work.

A spider hole.  

Gopher mounds.

An eroded, badlands-like area. 

Purple prickly pear.  The purple color usually indicates water stress -- a lack of water.

And you thought the Llano Estacado was a featureless wasteland!  Put your nose to the ground and you will see so much.  Bugs and plants, bones, skulls, mummified worms and grasshoppers, bug holes, scat, roots, lichen, moss, cow patties, rocks, caliche, loess, mudcracks, frost heave, dead trees, crystals!


Plants Amaze Me said...

Did Burr do the geology lectures too?
Will the salt lake be back as soon as it rains?
Did you taste the loess to see if it was salty??
We have frost heaving here in Michigan and sometimes it lifts the pavement of the road!
What a neat lizard, wish we would have seen one while we visited Texas. :)
Thanks for plugging my blog.

stratovolcano said...

Burr mainly sticks to the plants, animals, and human history. The lake will be back. There is no outlet to this basin. I did not taste the loess, although I did taste the soil at Tahoka Lake.

Steven Schafersman said...

The loess bluffs are composed of wind-deposited silt ablated by prevailing west winds from the dry playa floor and deposited on the east side of the playa. It would have a gritty texture and no taste.