Abstract

The Branch River terrace sequence includes terraces unmatched on the two sides of the fault, so that Suggate's (1960) rule for association of vertical and horizontal movement could be applied only after careful identification of matched features; the sequence is a practical example of Lensen's (1964a) general case of lateral faulting and lateral river erosion.

Reversal of direction of vertical movement took place early in the period of downcutting of the terraces, a period of about 20,000 years.

The rate of downcutting appears to be climatically controlled, while the rate of horizontal faulting appears to be relatively constant.

At this locality and other areas along the Wairau and Alpine faults, which show similar amounts of displacements of features of the same age, faulting is likely to occur about once every 500 to 900 years.

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