For several years now I've wondered why the Pecos River was saline enough to attract Seaside Dragonlets and Marl Pennants. Today I found an online post by Mikael Behrens, who got this information from a geologist specializing in Texas groundwater consulting (Allan Standen).
"He told me that back in the 1940s, just north of Iraan was an important area for oil production during World War II. Deep salty ground water was pumped up to flush oil reservoirs, and probably made the surface water brackish in that area to this day."
However, that explanation doesn't satisfy me. I can't fathom that saline water dumped many miles downstream would affect the water upstream for over 70 years. Doing a little online research, I now believe that floodplains above the headwaters of the Pecos River are more responsible. And I wonder if agriculture in those floodplains plays a role in the salinity too. "Some may involve dissolution of geological salts present above Girvin" also, per my research.
Here's a female Seaside Dragonlet photo that I took along the Pecos River on FM 1776 three years ago. (See post from Aug 5, 2016)
Back at the oasis today not much going on. I photographed these two common species because I had never had them together in the same frame before, so it was a chance for comparisons.
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| Neon Skimmer left, Flame Skimmer right |
I was amazed to discover something blooming. Can't explain why it's blooming. I've seen three butterflies so far this month.
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| Senna lindheimeriana |
And my sister found this little Southwestern Blackhead (Tantilla hobartsmithi) snake at her place a mile from the oasis.
It feels like fall. A little cooler than it had been. The swarms of archilochus (Black-chinned & Ruby-throated) hummers have moved through now. Just mostly Lucifers left, plus a few stragglers. If we get another rain this year it'll help my storage, but will probably be too late to help the vegetation get lush.
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