Barite is a ubiquitous minor phase in oceanic particulate matter, and pelagic sediments, particularly underlying regions of high biological productivity. Barite formation appears to be mediated by biological activity in the upper water column. There are indications that barite precipitates directly from seawater, in micro-environments containing decaying organic matter and siliceous remains. Barite is relatively insoluble and thus is less prone to burial diagenetic exchange than calcite. Barite contains a rather large spectrum of geochemically important minor and trace components at measurable concentrations. For these reasons barite has the potential of being a monitor of specific chemical and isotopic characteristics of seawater through time, such as Sr, S, Pb and Nd isotopic ratios, and sea water Sr/Ca ratio. Data indicating that marine barite is indeed a reliable monitor of oceanic chemistry and biological productivity will be presented.
Last updated: December 19, 2000