Atmospheric rivers

Just got back from the Antelope Valley. We drove out to Littlerock on the Pearblossom Highway for a date shake at Charlie Brown Farms. It was a perfect day for a drive, hot as hell and crystal clear, and the air in the desert was so dry it was enervating. Sweat evaporated off the skin instantly, giving the illusion of a chill, and we touched fingers and jumped at the static spark. The sky was a perfect blue, the wind promising fire, and off in the distance the Grapevine burned, a billow of smoke, a brushfire burning over itself, dying. The 14 is such a gorgeous run, all that maddening geology, layer upon layer, millions of years of time bent into ridiculous angles. There’s one layer that must be ten, even fifteen feet thick of rounded rock and rough gravel cemented into conglomerate. Sandstone above and below. Even whizzing past at 75 mph I was awestruck at the violence in it, the tale of an atmospheric river of Amazonian proportions that one wet winter millions of years ago filled this long dead river valley thirty feet deep in land scoured roughly off the surrounding hills. If anything had lived in that river before, it was dead then, gone, washed away or buried. The debris and stones and hilltop soils remained, and were buried by sand left as the river, renewed, coursed its lazy way above, shifting with the season and laying down sand in fractions of inches. It hardened into sandstone that, like its equal below, trapped the layer of rough conglomerate. More layers–sandstone, shales, some lesser flood debris–are laid down slowly overhead, hundreds of feet thick, and eventually the pressure compresses our thirty feet of flood debris into its current compacted ten. It’s cemented now, like a badly mixed concrete, full of rocks that tumble out in the rain. But even from down here on the highway it’s an impressive sight, one year’s worth of sedimentation, one rainy season really, perhaps even just a few day’s worth, compacted into ten or fifteen rough feet, between who knows how many centuries of hardened sand above and below it. Uplift and seismic pressure–the San Andreas Fault is just behind these Sierra Pelona Mountains that we’ve been driving through–have left the tale of this deluge in a sheer rock wall a hundred feet above us. Nothing sits still in California, nothing stays in place a billion years as in Australia. There are perfect fossil beaches in the Australian outback billions of years old, while an hour north of Los Angeles there is bottomland a few million years old that is now high in the Sierra Pelona with the hawks and circling vultures. I drove past, quietly awestruck, and as the rock disappeared in the rearview mirror I thought about the atmospheric rivers to come, and alluvial plains full of homes on streets full of water.

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