Teate, mis on Mojave kõrbes kõige üllatavam, haruldasem leid? Ei, mitte väiksem või suurem kullakamakas, kuigi sellegi otsa võib lotovõitjast matkaja sattuda, kui hoolega kanjoneid kammib. Kõige haruldasem leid on hoopiski looduslik veesilm. Ja näe, mul ning Paul õnnestus ühe sellise harulduse otsa komistada. Polnud teine küll teab mis suur, kuid ümbrus oli tihedalt värskeid loomajälgi täis, järelikult igapäevases kasutuses. Meiesugused, kel veepudel seljakotist võtta, otse loomulikult tolle roheka värvusega, biomassist paksuvõitu ollusega janu kustutama ei tõtanud. Aga kui tegemist olnuks ellujäämisküsimusega, siis küll ei kõhkleks. Ja kui ellujääjal veel nii peenike vidin nagu veepuhastusfilter kaasas juhtuks olema, poleks tarvis kõhulahtisususega riskidagi.
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Natural potholes in flat expanses of rock in desert country collect rainwater and often hold it long after streams have stopped flowing. Water pockets can be a vital source of water for wildlife — and they have even helped human desert travelers survive when their water supplies run out. Potholes, also referred to as weathering pits, tanks, tinajas, and waterpockets, are usually not a part of an active drainage; rather, they often form on flat or slightly dipping bedrock, typically sandstone surfaces. Acting as rain gauges, they capture water directly from precipitation. Potholes range in size from a few inches across to large cavities more than 50 feet deep that contain hundreds of gallons of water. Their enlargement is slow on the human timescale, but over longer periods of time the complex interactions of rock, water, and life gradually increase the dimensions of these hollows.
Weathering and erosion of potholes results, at least in part, from biological activity. Quartz sandstone is ordinarily resistant to moisture- induced chemical changes but can be more rapidly altered through “geomicrobiologic” processes. Some species of bacteria are capable of “consuming” siliceous minerals, and plants such as diatoms then sequester the silicon and other elements put into solution. When pools dry up, diatom skeletons, organics, and other fine particles are subsequently carried out of the pothole by winds.
March 09/2022 Foto: Paul
“Water, water, water... There is no shortage of water in the desert but exactly the right amount...unless you try to establish a city where no city should be.” ― Edward Abbey, Desert Solitaire
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