Abstract
The application of novel isotopic systematics has widespread use in geologic applications relating to diagenetic alteration. Previous studies have elucidated changes in conventional stable isotopic systematics (δ13C & δ18O), showing how meteoric or marine diagenetic horizons can be identified through geochemical indicators. Here we used a combination of more non-conventional geochemical proxies (δ11B, δ34S CAS, δ34S PW, and ∆47) to investigate a highly variable sample set of carbonates from a wide range of locations and diagenetic histories. Availability of SO4(2-) in seawater and its incorporation into carbonate minerals as CAS has allowed for an expanded understanding of diagenetic bacterial processes within carbonate sediments as they have been altered through time. In an effort to better constrain the significance of sulfur cycling and the δ34S value during recrystallization and diagenesis, shallow and deeper-water carbonate sediments were recovered from various drilling programs and legs from Ontong Java Plateau (DSDP Leg 30), The Great Australian Bight (ODP Leg 182), and The Maldives (IODP Expedition 359). Where applicable, existing porewater sulfate δ34S values were also measured. Diagenetic reactions influencing the pH of recrystallization commonly perturb the geologic record, often leaving minimal evidence visible to those collecting samples, and thus influencing reconstructions made within the scientific community. For this reason, samples from Clino, in The Bahamas, have been assessed for their primary δ11B values from present into the Miocene, anticipating large deviations from this value during diagenetic alteration. Such changes in δ11B values provide context and act as a warning to those making pH reconstructions in the deeper geologic record, having significant implications to early ocean chemistry.