Geomorphic evidence of multiple surface ruptures of the Merasjärvi “postglacial fault”, northern Sweden

ABSTRACT

Postglacial faults in Sweden are generally believed to have ruptured to the surface once either during or shortly after the late Weichselian deglaciation. Stratigraphic data from multiple scarps support or are consistent with this hypothesis and, until now, no data refute it. This study presents geomorphic evidence that a segment of the Merasjärvi fault in northern Sweden ruptured to the surface at least twice. The timing of the fault ruptures is poorly constrained because the scarp lies within a preserved glacial landscape. Crosscutting relationships indicate that the scarp is younger than the early Weichselian but suggest that parts of the scarp existed beneath the late Weichselian ice sheet.

KEYWORDS:

• Postglacial fault
• paleoseismicity
• Sweden
• Merasjärvi
• glacially induced fault
• fault scarp

Acknowledgments

The authors wish to thank R. Arvidsson for thoughtful comments as wells G. Brooks and two anonymous reviewers who helped to improve the quality and clarity of the manuscript. The project was made possible by an SGU internal research and development grant.

Disclosure statement

No potential conflict of interest was reported by the authors.