Showing papers by "Jay L. Banner published in 2006"
TL;DR: In this article, the authors investigate mechanisms that may account for the kinetic isotope effects during speleothem calcite growth and find that the calcite calcite was deposited with distinct δ 18 O and δ 13 C compositions that increase progressively away from the growth axis.
Abstract: The application of stable isotopes in speleothem records requires an understanding of the extent to which speleothem calcite isotopic compositions refl ect the compositions of the cave waters from which they precipitate. To test for equilibrium precipitation, modern speleothem calcite was grown on glass plates, so that the carbon and oxygen isotope composition of the calcite and the water from which it precipitated could be directly compared. The plates were placed on the tops of three actively growing stalagmites that occupy a 1 m 2 area in Harrison’s Cave, Barbados, West Indies. Only some of the plate δ 13 C values and none of the plate δ 18 O values correspond to equilibrium values, indicating signifi cant kinetic isotope effects during speleothem calcite growth. We investigate herein mechanisms that may account for the kinetic isotope effects. On each plate, speleothem calcite was deposited with distinct δ 18 O and δ 13 C compositions that increase progressively away from the growth axis, with up to 6.6‰ 13 C and 1.7‰ 18 O enrichments. The positive δ 13 C
281 citations