QDM magnetic microscopy dataset of a speleothem from Morocco

The dataset was measured on a Quantum Diamond Microscope (QDM) at Harvard University, using a stalagmite from Wintimdouine cave (Morroco). We performed a magnetic map over a sample section of approximately 1410 μm × 2256 μm with a grid spacing of 2.35 μm and a sensor-sample distance of approximately 5 μm, totaling 576,000 data points. The data were taken in projected magnetic microscopy (PMM) mode and converted to the vertical component of magnetic field (𝑏𝑧). In this sample, the magnetic remanence is carried by magnetite and hematite. We apply two IRM pulse fields parallel to the sample surface, 2.7 T and 0.3 T, respectively, toward the +Y and -Y directions. The high coercivity grains (hematite) would point towards +Y and the low coercivity ones (magnetite) would align in the -Y direction.