Skip to main content

New c. 270kyr strike-slip and uplift rates for the southern Alpine Fault and implications for the New Zealand plate boundary

Journal Article


Abstract


  • Along 100 km of the Alpine Fault, major valleys and glacial deposits can be matched across an 8000 m dextral offset. We use paleontologic and stratigraphic age constraints to date c. 270 ka marine sediments uplifted to 600 m elevation and overlying c. 270 ka glacial deposits related to the 8000 m dextral offset. These constraints yield a fault-proximal Australian plate uplift rate of 2.6 (−0.5/+0.4) mm/yr and an Alpine Fault dextral slip rate of 29.6 (−2.5/+4.5) mm/yr. Our rates resolve an apparent along-strike drop in strike-slip rate and instead support a relatively constant along-strike dextral slip rate of ∼28 mm/yr (∼80% of current Australian-Pacific plate boundary motion). We argue that the rate of dextral slip on the southern Alpine Fault has been relatively constant over the last ≥3.5 myr, and that ductile fault processes may rate-limit the fault from accommodating a progressively higher percentage of plate boundary motion through time (i.e., the fault reached maturity long ago). The spatiotemporally constant strike-slip rate of the southern Alpine Fault and a previously published paleoseismic record of near-regular earthquake recurrence both characterize the Alpine Fault as a mature plate boundary fault zone that behaves in a constant way with behavior predictable over timescales of thousands and hundreds of thousands of years.

Authors


  •   Barth, N (external author)
  •   Kulhanek, D (external author)
  •   Beu, A G. (external author)
  •   Murray-Wallace, Colin V.
  •   Hayward, B (external author)
  •   Mildenhall, D (external author)
  •   Lee, Daphne E. (external author)

Publication Date


  • 2014

Citation


  • Barth, N. C., Kulhanek, D. K., Beu, A. G., Murray-Wallace, C. V., Hayward, B. W., Mildenhall, D. C. & Lee, D. E. (2014). New c. 270kyr strike-slip and uplift rates for the southern Alpine Fault and implications for the New Zealand plate boundary. Journal of Structural Geology, 64 39-52.

Scopus Eid


  • 2-s2.0-84901267724

Ro Metadata Url


  • http://ro.uow.edu.au/smhpapers/2076

Number Of Pages


  • 13

Start Page


  • 39

End Page


  • 52

Volume


  • 64

Abstract


  • Along 100 km of the Alpine Fault, major valleys and glacial deposits can be matched across an 8000 m dextral offset. We use paleontologic and stratigraphic age constraints to date c. 270 ka marine sediments uplifted to 600 m elevation and overlying c. 270 ka glacial deposits related to the 8000 m dextral offset. These constraints yield a fault-proximal Australian plate uplift rate of 2.6 (−0.5/+0.4) mm/yr and an Alpine Fault dextral slip rate of 29.6 (−2.5/+4.5) mm/yr. Our rates resolve an apparent along-strike drop in strike-slip rate and instead support a relatively constant along-strike dextral slip rate of ∼28 mm/yr (∼80% of current Australian-Pacific plate boundary motion). We argue that the rate of dextral slip on the southern Alpine Fault has been relatively constant over the last ≥3.5 myr, and that ductile fault processes may rate-limit the fault from accommodating a progressively higher percentage of plate boundary motion through time (i.e., the fault reached maturity long ago). The spatiotemporally constant strike-slip rate of the southern Alpine Fault and a previously published paleoseismic record of near-regular earthquake recurrence both characterize the Alpine Fault as a mature plate boundary fault zone that behaves in a constant way with behavior predictable over timescales of thousands and hundreds of thousands of years.

Authors


  •   Barth, N (external author)
  •   Kulhanek, D (external author)
  •   Beu, A G. (external author)
  •   Murray-Wallace, Colin V.
  •   Hayward, B (external author)
  •   Mildenhall, D (external author)
  •   Lee, Daphne E. (external author)

Publication Date


  • 2014

Citation


  • Barth, N. C., Kulhanek, D. K., Beu, A. G., Murray-Wallace, C. V., Hayward, B. W., Mildenhall, D. C. & Lee, D. E. (2014). New c. 270kyr strike-slip and uplift rates for the southern Alpine Fault and implications for the New Zealand plate boundary. Journal of Structural Geology, 64 39-52.

Scopus Eid


  • 2-s2.0-84901267724

Ro Metadata Url


  • http://ro.uow.edu.au/smhpapers/2076

Number Of Pages


  • 13

Start Page


  • 39

End Page


  • 52

Volume


  • 64