Abstract
Major ion compositions of primary fluid inclusions from terminal Proterozoic (ca. 544 Ma) and Early Cambrian (ca. 515 Ma) marine halites indicate that seawater Ca2+ concentrations increased approximately threefold during the Early Cambrian. The timing of this shift in seawater chemistry broadly coincides with the "Cambrian explosion," a brief drop in marine 87Sr/86Sr values, and an increase in tectonic activity, suggesting a link between the advent of biocalcification, hydrothermal mid-ocean-ridge brine production, and the composition of seawater. The Early Cambrian surge in oceanic [Ca2+] was likely the first such increase following the rise of metazoans and may have spurred evolutionary changes in marine biota.
Original language | English |
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Pages (from-to) | 473-476 |
Number of pages | 4 |
Journal | Geology |
Volume | 32 |
Issue number | 6 |
DOIs | |
State | Published - Jun 2004 |
Keywords
- Biomineralization
- Cambrian explosion
- Evaporites
- Fluid inclusions
- Seawater