Enhancing the Success Rate of Paleointensity Measurements by Integrating Visible and Near‐Infrared Reflectance Spectroscopy and Rock Magnetism

Abstract Variations in the paleointensity of the Earth's magnetic field are intrinsically linked to the evolution of planetary interior dynamics and surface environmental conditions. However, the reliability of absolute paleointensity experiments is often compromised by the non‐ideal magnetic behavior of multi‐domain grains and alteration of magnetic minerals. To mitigate these challenges, besides conventional rock magnetic methods, this study also employs Visible and Near‐Infrared Reflectance (VNIR) spectroscopy as a rapid screening tool to identify thermally unstable mineral phases that can distort experimental results. Systematic rock magnetic analyses reveal that samples with more pronounced single‐domain‐like magnetic properties achieve significantly higher success rates in paleointensity experiments. The implementation of VNIR‐based screening increased the average success rate of analyzed samples by a factor of 1.9 compared to magnetic selection alone. We recommend using VNIR screening with M rs /M s ≥ 0.16 as the sample selection criterion, which can increase the success rate threefold while maintaining sufficient sample availability. By integrating VNIR spectroscopy with conventional rock magnetic methodologies, this study presents a robust approach to enhance the reliability and success rates of paleointensity determinations.