singular debris?

[Barnhart]

In the first sense as provided by most dictionaries, _debris_ is quite
recognizably plural.  However, in the second definition given in the
Century Dictionary (1889-1914) we find:

"2. In geol., a mass of rocky fragments irregularly accumulated at any
one spot: as, the debris at the base of a cliff: used as both a
singular and a plural by French and English writers.  See drift,
detritus, and screes."

Regards,
David K. Barnhart
barnhart at highlands.com