Source : Webster's Revised Unabridged Dictionary (1913)

Palaetiology \Pa*l[ae]`ti*ol"o*gy\, n. [Pal[ae]o- +
   [ae]tiology.]
   The science which explains, by the law of causation, the past
   condition and changes of the earth. --
   {Pa*l[ae]`ti*o*log"ic*al}, a.