Magnetic Field Measurements above a Phonolite Diatreme near Rockeskyll, West Eifel, Germany

Magnetic total field data were collected on a meadow close to the volcano Rockeskyller Kopf near Reckeskyll, West Eifel, Germany. The data were obtained with the proton magnetometer ENVI-MAG (Scintrex) and a laser tachymeter was used to determine the exact position of the measurement points. The measurements were carried out on four different days in spring 2011. No corrections were made for diurnal variations as the diurnal variations were negligible compared to the anomaly. The main objective of the study was to locate and model the potential eruption centre of the exceptionally large sanidine crystals that were found nearby. These crystals probably originate from phonolitic tuff and have formed in a highly differentiated magma chamber.