Abrupt strike-slip fault to subduction transition: The Alpine Fault-Puysegur Trench connection, New Zealand

Tectonics ◽  
2000 ◽  
Vol 19 (4) ◽  
pp. 688-706 ◽  
Author(s):  
Jean-Frédéric Lebrun ◽  
Geoffroy Lamarche ◽  
Jean-Yves Collot ◽  
Jean Delteil
Keyword(s):  
New Zealand ◽  
Strike Slip ◽  
Strike Slip Fault ◽  
Alpine Fault

Erosion rates of the New Zealand Southern Alps reflect long-term tectonics and transient climate

2021 ◽  
Author(s):  
Duna Roda-Boluda ◽  
Taylor Schildgen ◽  
Hella Wittmann-Oelze ◽  
Stefanie Tofelde ◽  
Aaron Bufe ◽  
...  
Keyword(s):  
New Zealand ◽  
Strike Slip ◽  
Southern Alps ◽  
Fault System ◽  
Tectonic Deformation ◽  
Seismic Cycle ◽  
Erosion Rates ◽  
Alpine Fault ◽  
Oblique Convergence

<p>The Southern Alps of New Zealand are the expression of the oblique convergence between the Pacific and Australian plates, which move at a relative velocity of nearly 40 mm/yr. This convergence is accommodated by the range-bounding Alpine Fault, with a strike-slip component of ~30-40 mm/yr, and a shortening component normal to the fault of ~8-10 mm/yr. While strike-slip rates seem to be fairly constant along the Alpine Fault, throw rates appear to vary considerably, and whether the locus of maximum exhumation is located near the fault, at the main drainage divide, or part-way between, is still debated. These uncertainties stem from very limited data characterizing vertical deformation rates along and across the Southern Alps. Thermochronology has constrained the Southern Alps exhumation history since the Miocene, but Quaternary exhumation is hard to resolve precisely due to the very high exhumation rates. Likewise, GPS surveys estimate a vertical uplift of ~5 mm/yr, but integrate only over ~10 yr timescales and are restricted to one transect across the range.</p><p>To obtain insights into the Quaternary distribution and rates of exhumation of the western Southern Alps, we use new <sup>10</sup>Be catchment-averaged erosion rates from 20 catchments along the western side of the range. Catchment-averaged erosion rates span an order of magnitude, between ~0.8 and >10 mm/yr, but we find that erosion rates of >10 mm/yr, a value often quoted in the literature as representative for the entire range, are very localized. Moreover, erosion rates decrease sharply north of the intersection with the Marlborough Fault System, suggesting substantial slip partitioning. These <sup>10</sup>Be catchment-averaged erosion rates integrate, on average, over the last ~300 yrs. Considering that the last earthquake on the Alpine Fault was in 1717, these rates are representative of inter-seismic erosion. Lake sedimentation rates and coseismic landslide modelling suggest that long-term (~10<sup>3</sup> yrs) erosion rates over a full seismic cycle could be ~40% greater than our inter-seismic erosion rates. If we assume steady state topography, such a scaling of our <sup>10</sup>Be erosion rate estimates can be used to estimate rock uplift rates in the Southern Alps. Finally, we find that erosion, and hence potentially exhumation, does not seem to be localized at a particular distance from the fault, as some tectonic and provenance studies have suggested. Instead, we find that superimposed on the primary tectonic control, there is an elevation/temperature control on erosion rates, which is probably transient and related to frost-cracking and glacial retreat.</p><p>Our results highlight the potential for <sup>10</sup>Be catchment-averaged erosion rates to provide insights into the magnitude and distribution of tectonic deformation rates, and the limitations that arise from transient erosion controls related to the seismic cycle and climate-modulated surface processes.</p><p> </p><p> </p>

scholarly journals Fault zone architecture of a large plate-bounding strike-slip fault: a case study from the Alpine Fault, New Zealand

Solid Earth ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 95-124 ◽  
Author(s):  
Bernhard Schuck ◽  
Anja M. Schleicher ◽  
Christoph Janssen ◽  
Virginia G. Toy ◽  
Georg Dresen
Keyword(s):  
Fault Zone ◽  
Complex Geometry ◽  
Strike Slip ◽  
Strike Slip Fault ◽  
Unconsolidated Sediments ◽  
Large Plate ◽  
Alpine Fault ◽  
Slip Planes ◽  
Fault Zone Architecture ◽  
Geophysical Investigations

Abstract. New Zealand's Alpine Fault is a large, plate-bounding strike-slip fault, which ruptures in large (Mw>8) earthquakes. We conducted field and laboratory analyses of fault rocks to assess its fault zone architecture. Results reveal that the Alpine Fault Zone has a complex geometry, comprising an anastomosing network of multiple slip planes that have accommodated different amounts of displacement. This contrasts with the previous perception of the Alpine Fault Zone, which assumes a single principal slip zone accommodated all displacement. This interpretation is supported by results of drilling projects and geophysical investigations. Furthermore, observations presented here show that the young, largely unconsolidated sediments that constitute the footwall at shallow depths have a significant influence on fault gouge rheological properties and structure.

Distributed deformation in the lower crust and upper mantle beneath a continental strike-slip fault zone: Marlborough fault system, South Island, New Zealand

Geology ◽  
2004 ◽  
Vol 32 (10) ◽  
pp. 837 ◽  
Author(s):  
Charles K. Wilson ◽  
Craig H. Jones ◽  
Peter Molnar ◽  
Anne F. Sheehan ◽  
Oliver S. Boyd
Keyword(s):  
New Zealand ◽  
Fault Zone ◽  
Upper Mantle ◽  
Lower Crust ◽  
Strike Slip ◽  
Strike Slip Fault ◽  
Fault System ◽  
Crust And Upper Mantle

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

2014 ◽  
Vol 64 ◽  
pp. 39-52 ◽  
Author(s):  
N.C. Barth ◽  
D.K. Kulhanek ◽  
A.G. Beu ◽  
C.V. Murray-Wallace ◽  
B.W. Hayward ◽  
...  
Keyword(s):  
New Zealand ◽  
Plate Boundary ◽  
Strike Slip ◽  
Alpine Fault ◽  
Uplift Rates

scholarly journals Fault zone architecture of a large plate-bounding strike-slip fault: a case study from the Alpine Fault, New Zealand

2019 ◽  
Author(s):  
Bernhard Schuck ◽  
Anja M. Schleicher ◽  
Christoph Janssen ◽  
Virginia G. Toy ◽  
Georg Dresen
Keyword(s):  
Fault Zone ◽  
Complex Geometry ◽  
Damage Zone ◽  
Strike Slip ◽  
Strike Slip Fault ◽  
Unconsolidated Sediments ◽  
Multiple Slip ◽  
Large Plate ◽  
Alpine Fault ◽  
Fault Zone Architecture

Abstract. New Zealand's Alpine Fault is a large, plate-bounding strike-slip fault, that ruptures in large (MW > 8) earthquakes. Its hazard potential is linked to its geometrical properties. We conducted field and laboratory analyses of fault rocks to elucidate their influence on its fault zone architecture. Results reveal that the Alpine Fault zone has a complex geometry, comprising an anastomosing network of multiple slip planes that have accommodated different amounts of displacement. Within it, slip zone width is demonstrably not related to lithological differences of quartzofeldspathic lithologies, which vary slightly along- strike. The young, largely unconsolidated sediments that constitute the footwall in some outcrops have a much more significant influence on fault gouge rheological properties and structure. Additionally, seismic investigations indicate that the exposed complex fault zone architecture extends into the basement. This study reveals the Alpine Fault contains multiple slip zones surrounded by a broader damage zone; properties elsewhere associated with carbonate or phyllosilicate-rich faults.

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