The application and implications of rock weathering‐rind dating to a large rock avalanche, Craigieburn Range, Canterbury, New Zealand

Abstract

Weathering‐rind dating of a rock‐avalanche deposit in the Ryton valley, Craigieburn Range, Canterbury, New Zealand, previously considered to be of one event, revealed two events, one at approximately A.D. 1422 (±96 years) and one at approximately A.D. 1632 (±55 years). Two distinct source areas were identified, with the younger avalanche deposit mantling part of the older deposit. Correlation with other rock avalanche events in the Southern Alps suggests that between A.D. 1400 and 1500 there was a large magnitude seismic event causing widespread, coseismic rock avalanching. Further correlation with other rock avalanche dates in this region should contribute to continued refinement of paleoseismicity in the Canterbury region.

Keywords:

• rock avalanche(s)
• Ryton valley
• weathering rinds
• dating
• earthquakes