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

Progress in Earth and Planetary Science

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

	Modern shell	Cement	Puncta filling cements accounting for 5% of the shell volumes		Puncta filling cements accounting for 10% of the shell volumes
	Modern shell	Cement	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