Table 6 Ice surface levels at the time of the Twannberg fall

Argument 1: Ice-transported meteorites associated with till/alpine clasts west of Hohmatt (47° 8.10’N 7° 11.38’E) at an altitude of 1070 m a.s.l

Conclusion: MIS 6 ice surface level was at least 1090¹ m a.s.l., 160 m higher than during the LGM

Rating: Very strong argument, no other interpretation appears possible

Argument 2: Ice-transported meteorites associated with till/alpine clasts northeast of Mt. Sujet at altitudes of 1040 to 1090 m in the valley of Les Prés-d’Orvin (47° 8.940’N 7° 10.0’E)

Conclusion: MIS 6 ice surface level was at least 1130¹ m a.s.l., 200 m higher than during the LGM

Rating: Very strong argument. If glacial transport would have occurred along the north flank of Mt. Sujet, a higher ice level would be required

Argument 3: Jobert boulder and nearby alpine clasts (47° 9.882’N 7° 10.696’E)

Conclusion: Maximum ice level reached at least 1330¹ m a.s.l., 400 m higher than during LGM. If this happened during MIS 6 as is indicated by exposure ages², the Twannberg fall must have occurred after glacial maximum at a time when the ice surface level was lower than ~ 1250 m a.s.l. based on the preservation of the primary distribution of meteorites on Mont Sujet

Rating: Argument depends on the transport age of the Jobin boulder and other high-lying boulders², a transport prior to MIS 6 is possible