the.com/stratum
A single page in the planet's autobiography, written in mud and pressed flat by time.
means One distinct layer of material, especially rock or soil, deposited and distinguishable from the layers around it.
from Latin stratum, meaning something spread or laid down, from sternere, to spread out — the same root that paved your stratus clouds and your streets.
Plural trapMany layers are strata, never stratums.
Social copySociologists borrowed it for class layers wholesale.
Reading orderLower layers are older, barring geological mischief.