Uplift history and geomorphic development of the Southern Alps, New Zealand, assessed by fission track analysis
type: CreativeWork
description: The uplift history and geomorphic development of the Southern Alps has been studied, using fission track analysis of basement samples in combination with measurement of the present geomorphology of the Southern Alps. During the late Cenozoic the Pacific plate has been converging obliquely with the Australia plate in South Island, New Zealand. A result of this convergence has been the growth of a major mountain range - the Southern Alps - at the leading edge of the Pacific plate. The results of fission track analysis of 140 samples from 13 transects across the 300 km-long central sector of the Southern Alps reported here, establish the late Cenozoic vertical kinematics (amount, age, and rate of rock uplift) of the Pacific crust underlying the Southern Alps. The pattern of late Cenozoic rock uplift is asymmetrical with respect to the Alpine Fault, being a maximum (19 km) immediately east of the central part of the Fault, with lesser values at the eastern (3 km), northern (10 km) and southern (8 km) extremities of the Southern Alps. The age of the start of rock uplift varies spatially across the Southern Alps, the earliest indications from fission track analysis being at 8 Ma ago at the southern end of the Southern Alps, decreasing to 5 Ma ago at the northern end and 3 Ma ago along the southeastern margin. This age variation reflects the longer time over which the southern parts of the Southern Alps have been in collision. The rate of propagation of rock uplift southeastwards into the Pacific plate has been 30 mm/a, nearly 4 times the late Cenozoic average rate of convergence normal to the plate boundary. Late Cenozoic mean rock uplift rates range from a maximum of ∼2.8 mm/a at the Alpine Fault to a minimum of ∼1.0 mm/a in the east. Uplift has accelerated over time, but only significantly since 1.3 ± 0.3 Ma ago. The fission track data in combination with topographic data have been analysed to quantify the response of the surface of the Pacific plate to the late Cenozoi…
abstract: The uplift history and geomorphic development of the Southern Alps has been studied, using fission track analysis of basement samples in combination with measurement of the present geomorphology of the Southern Alps. During the late Cenozoic the Pacific plate has been converging obliquely with the Australia plate in South Island, New Zealand. A result of this convergence has been the growth of a major mountain range - the Southern Alps - at the leading edge of the Pacific plate. The results of fission track analysis of 140 samples from 13 transects across the 300 km-long central sector of the Southern Alps reported here, establish the late Cenozoic vertical kinematics (amount, age, and rate of rock uplift) of the Pacific crust underlying the Southern Alps. The pattern of late Cenozoic rock uplift is asymmetrical with respect to the Alpine Fault, being a maximum (19 km) immediately east of the central part of the Fault, with lesser values at the eastern (3 km), northern (10 km) and southern (8 km) extremities of the Southern Alps. The age of the start of rock uplift varies spatially across the Southern Alps, the earliest indications from fission track analysis being at 8 Ma ago at the southern end of the Southern Alps, decreasing to 5 Ma ago at the northern end and 3 Ma ago along the southeastern margin. This age variation reflects the longer time over which the southern parts of the Southern Alps have been in collision. The rate of propagation of rock uplift southeastwards into the Pacific plate has been 30 mm/a, nearly 4 times the late Cenozoic average rate of convergence normal to the plate boundary. Late Cenozoic mean rock uplift rates range from a maximum of ∼2.8 mm/a at the Alpine Fault to a minimum of ∼1.0 mm/a in the east. Uplift has accelerated over time, but only significantly since 1.3 ± 0.3 Ma ago. The fission track data in combination with topographic data have been analysed to quantify the response of the surface of the Pacific plate to the late Cenozoi…
author: Tippett, J. Mark
license: https://researchcommons.waikato.ac.nz/bitstreams/c7a691e6-0c2d-4808-b8e8-0f9228946f22/download
date published: 1992
date modified: 2026-07-24T05:57:18Z
provider: University Waikato
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: The University of Waikato