overburden

English

Etymology

From over- +‎ burden.

Verb

overburden (third-person singular simple present overburdens, present participle overburdening, simple past and past participle overburdened)

1. To overload or overtax

Noun

overburden (plural overburdens)

1. (geology) The rock and subsoil that lies above a mineral deposit such as a coal seam.
   • 2004, Richard Fortey, The Earth, Folio Society 2011, p. 163:

     Such rocks have been changed by baking in a terrestrial pressure-cooker. Then they have been disinterred: kilometres of overburden must have been removed.

2. (archaeology) A sterile stratum that lies above the stratum being investigated

References

Wikipedia