Geology of the Harper and Avoca River Valleys, Mid-Canterbury, New Zealand

Abstract

Soft Tertiary sandstone, mudstone, and conglomerate are preserved in a narrow strip parallel to the Harper Fault, within indurated sandstone and mudstone probably Triassic in age on the east flank of the Southern Alps. The structure of the Tertiary rocks is interpreted principally in terms of mid-Tertiary and late-Tertiary folding, to which some of the complexities of the basement structure are also attributed. Valley deposits and valley form are interpreted as the result of two ice advances during the Last Glaciation.