Affordable Access

A geochemical and mineralogical investigation of calcite growth and its interactions with divalent cadmium, manganese, and zinc /

Authors
Publisher
McGill University
Publication Date
Keywords
  • Geochemistry.
Disciplines
  • Mathematics

Abstract

Cd2+, Mn2+ and Zn2+ respectively inhibited the growth of the (101¯0), (011¯2) and (0001) surfaces of calcite and were preferentially incorporated in the stabilized corresponding growth sectors. DMe values unaffected by growth kinetics approach DMe,ideal when calculated from analyses of the stabilized growth sectors and may represent equilibrium values. DCd,eq = 2235 +/- 400 at {101¯0}, DMn,eq = 97 +/- 6 at {011¯2} and DZn,eq = 190 +/- 32 at (0001). While at {101¯4}, D Cd and DMn reached only 500 +/- 120 and 21 +/- 3.4, respectively. These findings demonstrate that equilibrium partitioning is attained only when (1) calcite growth reaches stoichiometric saturation and "morphological equilibrium" with the aqueous solution and (2) if metal incorporation occurs entirely at surface sites offering optimal geometry and coordination for ion incorporation. A conceptual model is proposed to quantify the contribution of sector zoning on DMe values derived from bulk analyses of precipitates.

There are no comments yet on this publication. Be the first to share your thoughts.