The ultralow viscosity of volatile-rich kimberlite magma: Implications for the water content of primitive kimberlite melts.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39241074.
- Also identified by DOI 10.1126/sciadv.ado8550 and PMC identifier 11378914.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The eruption of deeply sourced kimberlite magma offers the fastest route to bring deep-seated volatiles back to the Earth's surface. However, the viscosity of kimberlite magma, a factor governing its migration and eruption dynamics within Earth, remains poorly constrained. We conducted synchrotron in situ falling sphere viscometry experiments to examine kimberlite magma with different volatile contents (0 to 5 wt % H<sub>2</sub>O and 2 to 8 wt % CO<sub>2</sub>) under high pressure-temperature conditions. The results reveal that the viscosity of volatile-rich kimberlite magma is ~1 to 2 orders lower than that of mid-ocean ridge basalt (MORB) and comparable to the ultramobile pure carbonate melt. Using the measured viscosity values, we simulated the ascent and eruption process of kimberlite magma. We found that a minimum content of ~0.5 wt % water in the primitive magma is necessary to allow the ultrafast eruption process of kimberlite, thereby enabling the preservation of diamonds and high-pressure mineral inclusions transported by the magma.