GREAT SALT LAKE
Great Salt Lake (GSL) in
northern Utah is the world's largest body of significantly salty water.
The saltiness of the lake water ranges from about 6% to 27% (seawater averages
3.5% salinity). Salt has accumulated in Great Salt Lake for many
thousands of years because the basin lacks an outlet. During the
Pleistocene (the last Ice Age), Great Salt Lake extended much, much further
than its present ~1700 square miles. The Pleistocene-aged precursor to
GSL is known as Lake Bonneville (actually, four different lake names are
used to refer to different stages of the Pleistocene GSL precursor). At
its maximum, Lake Bonneville covered ~20,000 square miles.
Great Salt Lake (looking ~ N) - Silver
Island Mountains & the Bonneville Salt Flats from a few miles east of
Wendover (a small town on the Utah-Nevada border).
Great Salt Lake, as seen from Saltair,
Utah, USA.
Great Salt Lake oolites - the grayish-colored,
shoreline sediments here are oolites - calcareous (aragonitic) spheres
formed by back-and-forth rolling in the water by wave action and precipitation
of CaCO3. Great Salt Lake is one of the few places ion Earth
where modern oolitic sediments can be seen forming in a nonmarine setting.
Mudcracks - modern mudcracks formed
in lacustrine evaporitic sediments near Saltair, Great Salt Lake, Utah, USA.
Puckered salt crust surface
& gas pockets developed in lacustrine evaporitic sediments near Saltair, Great Salt
Lake, Utah, USA. The gas pockets formed from decay of buried organic
matter.
Modern bird carcass
impregnated with salt from an evaporated portion of Great Salt Lake, near
Saltair, Utah. Salt is a great preservative, but I've never heard of
anyone finding soft-bodied fossils in ancient rock salt beds (not counting
still-living halobacteria isolated from late Precambrian & Phanerozoic rock
salts). Is there the potential, though?
Lake Bonneville lake
terraces (above & below): ancient lake terraces visible at the northern end
of the Oquirrh Mountains, southern margin of Great Salt Lake.
