Skip to main content

Advertisement

Table 2 Effect of puncta-filling cements to the isotopic composition and minor element concentrations of shell samples. We assume that the isotopic composition and minor element concentrations of the puncta-filling cements are identical to those of the cement formed by meteoric diagenesis. Then, we calculate the isotopic composition and minor element concentrations of the mixtures of shell and puncta-filling cements when the punctae are filled with such cements

From: The effects of meteoric diagenesis on the geochemical composition and microstructure of Pliocene fossil Terebratalia coreanica and Laqueus rubellus brachiopod shells from northeastern Japan

  Modern shell Cement Puncta filling cements accounting for 5% of the shell volumes Puncta filling cements accounting for 10% of the shell volumes
Shell + cement Δ* Shell + cement Δ*
T. coreanica
 Interval 2
  δ13C (‰) 1.01 to 1.36 − 18 0.06 to 0.39 − 0.96 − 0.89 to − 0.58 − 1.92
  δ18O (‰) 1.17 to 1.43 − 7 0.76 to 1.01 − 0.42 0.35 to 0.59 − 0.83
  Mn (ppm) 3** 6000 310 300 610 600
  Fe (ppm) 70** 14,000 770 700 1500 1400
  Sr (ppm) 960** 400 930 − 30 900 − 60
L. rubellus
 Interval 2
  δ13C (‰) 1.49 to 1.94 − 18 0.52 to 0.94 − 0.99 − 0.46 to 0.05 −  1.97
  δ18O (‰) 0.55 to 0.93 − 7 0.17 to 0.53 − 0.39 − 0.21 to 0.14 −  0.78
  Mn (ppm) 7** 6000 300 300 600 590
  Fe (ppm) 120** 14,000 810 690 1500 1380
  Sr (ppm) 820** 400 800 − 20 780 − 40
  1. *Δ = “shell + cement” − “modern shell”
  2. **Median