This is in DESERT COUNTRY, near the town of BURNS, OR; the lake is shallow, due to evaporation, and the bottom of the lake may be seen to exhibit concentric features with regular separation:
Lake Malheur ,OR
The separation occurs with PERIODIC “JERKS” or discontinuous EARTH TIDAL MOVEMENTS, which enlarges the size of the EXHIBITS. It is a fresh water lake, but has a companion to the west which is an EVAPORITIC BASIN with saline deposits (PLAYA, or PERIODIC DRYING SINK):
Lake Malheur SPIRAL REQUIRES 23 m.y. to complete (EXTRAPOLATION, by CALCULATION (NOT LIKELY that a spiral will successfully complete, since an INTERVENING, INTERFERING PROTRUSION or RISE W ILL OCCUR!).