calciferous epoch

from The Collaborative International Dictionary of English v.0.48

Calciferous \Cal*cif"er*ous\, a. [L. calx, calcis, lime +
   -ferous.]
   Bearing, producing, or containing calcite, or carbonate of
   lime.
   [1913 Webster]

   {Calciferous epoch} (Geol.), an epoch in the American lower
      Silurian system, immediately succeeding the Cambrian
      period. The name alludes to the peculiar mixture of
      calcareous and siliceous characteristics in many of the
      beds. See the Diagram under {Geology}.
      [1913 Webster]