Uplifted Marine Terraces Along the Alpine Fault, New Zealand

Science  05 Dec 1986:
Vol. 234, Issue 4781, pp. 1225-1228
DOI: 10.1126/science.234.4781.1225


Three types of evidence indicate that marine terraces are widespread in the Southern Alps of New Zealand. (i) Remnants of shore platforms occur as distinct levels of notched ridge crests and flat summits; degraded sea cliffs are common. (ii) Scattered quartz beach pebbles occur on 16 of 18 levels of exhumed shore platforms in the Fox- Franz Josef type area to altitudes as high as 1700 meters. (iii) Altitudinal spacings of New Zealand terrace flights allow correlation with 18 dated global marine terraces at New Guinea, which were formed during glacio-eustatic highstands of sea level within the last 336 x 103 years. Inferred uplift rates at Fox-Franz Josef increased from 3.2 to 7.8 meters per 103 years since about 135 x 103 to 140 x 103 years ago, presumably because of increased convergence between the Pacific and Australian plates.