Fig. 5: Differences in mass fractions and arsenic concentrations between agglutinated and micritic discrete microbial buildups in Hamelin Pool.
From: Arsenic enrichment patterns are defined by microbialite morphology, fabric, and accretion mechanism
A Mass fractions (wt%) of organic matter, micrite, trapped-and-bound (T&B) allochems, and siliciclastic fractions in agglutinated (n = 22) vs. micritic microbialites (n = 20) from Hamelin Pool. Significant differences were observed for micrite (Student’s t-test, t(40) = −2.670, p = 0.011), trapped-and-bound allochem (Student’s t-test; t(40) = −2.470, p = 0.018), and siliciclastic fractions (Welch’s t-test, t(31.65) = 3.074, p = 0.004); no significant difference was found for organic matter (Student’s t-test; t(40) = −1.773, p = 0.084). Error bars represent standard deviations. Arsenic concentrations (mg/kg) in micrite (B), trapped-and-bound (T&B) allochems (C), and organic matter (D) compared between agglutinated (n = 22) and micritic microbialites (n = 20). No significant differences were found for micrite (Student’s t-test, t(40) = 0.672, p = 0.506), trapped-and-bound allochems (Mann–Whitney U-test, W = 195.5, p = 0.715), or organic matter (Mann–Whitney U-test, W = 293, p = 0.068). Box plots display the median (center line), the 25th and 75th percentiles (box limits), whiskers extending to 1.5 times the interquartile range, and the mean (x-mark). Asterisks (*) denote statistically significant differences (p < 0.05); absence of a symbol indicates no significant difference.
