During the rainy season, a thin layer (less than 1 m) of brine covers much of the saline pan, but it evaporates rapidly, leaving a vast expanse of white salt that cracks to produce large polygons.

There are many varieties including bedded cherts that formed in the lake and intrusive dike-like bodies that penetrated through overlying sediments while the silica was soft.

Today, this harsh lacustrine environment excludes most organisms except microbial extremophiles, a few invertebrates (mostly insects), highly adapted fish (Alcolapia sp.

Burrows discovered in outcrops of the High Magadi Beds (~25–9 ka) that predate the modern saline (trona) pan show that beetles and other invertebrates inhabit this extreme environment when conditions become more favorable.

Burrows (cm-scale) preserved in magadiite in the High Magadi Beds are filled with mud, silt and sand from overlying sediments.

The burrows, probably produced by beetles, suggest that trace fossils can provide evidence for short-term (ranging from years to decades) changes in the contemporary environment that might not otherwise be recognized or preserved physically or chemically in the sediment record.