The northeast baulk of ET3 was expanded by 4 m in order to find out what the stair-like anomalies on the magnetometer images were. A 0.3 m section was excavated on the north baulk to study the profile of the clay layer above the bedrock.
At the current status of work, no solid evidence of a staircase has been found. The source of the anomalies remains unknown. The floor extending from the southwest baulk is currently being excavated approximately 2 m upslope, as a magnetic anomaly appears to crosscut this section. So far, a rock has been found, as well as very pulverized rock. Further information is needed, but it seems possible that the clay is magnetically neutral, and the rock is very magnetically susceptible. Therefore, even very pulverized rock may be seen as an anomaly when using a magnetometer, though when excavated, it is difficult to preserve in any meaningful manner.