Rapid eruption of the Columbia River flood basalt and correlation with the mid-Miocene climate optimum.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 30255148.
- Also identified by DOI 10.1126/sciadv.aat8223 and PMC identifier 6154988.
- Licence recorded as CC BY-NC.
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Abstract
Flood basalts, the largest volcanic events in Earth history, are thought to drive global environmental change because they can emit large volumes of CO<sub>2</sub> and SO<sub>2</sub> over short geologic time scales. Eruption of the Columbia River Basalt Group (CRBG) has been linked to elevated atmospheric CO<sub>2</sub> and global warming during the mid-Miocene climate optimum (MMCO) ~16 million years (Ma) ago. However, a causative relationship between volcanism and warming remains speculative, as the timing and tempo of CRBG eruptions is not well known. We use U-Pb geochronology on zircon-bearing volcanic ash beds intercalated within the basalt stratigraphy to build a high-resolution CRBG eruption record. Our data set shows that more than 95% of the CRBG erupted between 16.7 and 15.9 Ma, twice as fast as previous estimates. By suggesting a recalibration of the geomagnetic polarity time scale, these data indicate that the onset of flood volcanism is nearly contemporaneous with that of the MMCO.