Objective:

To provide a more precise dating of the 79 CE eruption of Mount Vesuvius using improved argon-40/argon-39 dating techniques.

Approach:

• Sample Collection: Researchers analyzed sanidine crystals from white pumice collected at Villa Poppea, approximately 1.8 kilometers from Pompeii.
• Dating Method: The team used argon-40/argon-39 dating, measuring the decay of potassium-40 to argon-40 to estimate the cooling time of the mineral.
• Analytical Techniques: Improvements included short neutron irradiation, cadmium shielding, laser-based incremental heating, and enhanced correction for interfering isotopes.

Key Findings:

• The eruption was dated to 87 ± 13 CE, consistent with the accepted date of 79 CE.
• Achieved a relative precision of 0.7 percent, significantly better than previous studies with uncertainties of approximately 100 years.
• Refined the decay constant for potassium-40 to argon-40 conversion, improving the precision of future argon-based dating.

Interpretation:

The study demonstrates that advancements in mass spectrometry and sample preparation can enhance the precision of dating volcanic events.

Limitations:

• The approach relies on the availability of suitable potassium-rich minerals.
• Performance may vary among volcanic deposits due to contamination and analytical interference.

Conclusion:

The findings could improve the accuracy of argon-based dating across geological time and aid in understanding volcanic hazards.

Sources:

• Science Advances