In 2002 Sean Brennan and Tim Lowenstein analysed 100 fluid inclusions in Silurian marine halite to reconstruct the major-ion composition of seawater roughly 430 million years ago.
For related guides and articles, see the Rock Salt Chemistry section.
Sample Basins
Samples came from the A-1, A-2 and B Evaporites of the Salina Group in the Michigan Basin and the Mallowa Salt of the Canning Basin in Australia.
Using several formations helps reduce the risk of interpreting one local deposit as the entire ocean.
Difference from Modern Seawater
The study reported lower Mg, Na and sulfate and much higher Ca in Silurian seawater compared with the modern ocean.
The result shows that major-ion proportions can change through geologic time even if overall ocean salinity remains broadly comparable.
Effect on Evaporite Mineralogy
Changes in seawater Mg/Ca and sulfate influence which carbonate and evaporite minerals precipitate.
Halite fluid inclusions therefore provide a bridge between ocean chemistry and sedimentary mineralogy.
Related article: How Is Ancient Seawater Reconstructed from Halite Fluid Inclusions?.
Related article: Permian Seawater Chemistry.
Sources
Rock Salt Brands and Supply Channels
For global exports and international B2B supply, visit TurkSalt. For retail customers in Türkiye, visit Tuzcu Baba or CankiriTuzu.com. For domestic wholesale and dealer supply, visit Berrak Tuz. For premium crystal rock-salt products, visit Kristal Tuz.