Scanning Synchrotron X-Ray Fluorescence Microanalysis for Tephrochronological Studies

On the border of China and North Korea, there is the only active stratovolcano in the eastern part of Asia: Mount Paektu (other names are Baitoushan and Changbaishan). It is widely known for one of the largest eruptions in the historical era, which occurred in the 10th century AD. On the volcanic-activity scale, the event is rated at seven points, this is the largest eruption in the last millennium. Modern research shows that the eruption of the Paektu volcano occurred in late autumn–winter 946 AD. This dating is supported by data obtained from the study of an ice core from North Greenland, in which traces of volcanic ash were found. At a depth of 860 mm (the age according to the calculation of annual layers is 942 AD ± 26 years), a layer 2–3 mm thick was found, which differed sharply in color and texture from the rest of the core material. Using a module of confocal X-ray microscopy, an optical section containing an anomalous layer was studied. 2D scanning with a focused beam of synchrotron radiation 20 µm in diameter was carried out. A large amount of microparticles with a high content of zirconium and yttrium was found inside the layer. The possibility of finding traces of the eruption of the Paektu volcano is discussed.