Figure 24.13 (a) (b) Ca2++2HC03 CaC03+C02+H20 H+HC03≥H2CO3 Dissolved Ca2+ HCO3 Calcareous exoskeletons A 日 面 且 Sinking ■ Upwelling Detrital CaCO3 Mineralization in sediments (c) 2012 Pearson Education,Inc The marine calcium (Ca)cycleFigure 24.13 Dissolved Ca2 HCO3  Detrital CaCO3 Calcareous exoskeletons Upwelling Sinking Ca2  2 HCO3  CaCO3  CO2  H2O H  HCO3  H2CO3 Mineralization in sediments © 2012 Pearson Education, Inc. The marine calcium (Ca) cycle