Integration of Structural Geology and Geomorphology in Quantifying the Role of Fault-Related Folds in New Zealand Plate Boundary Deformation

David Oakley
Pennsylvania State University, Department of Geosciences State College, Pennsylvania, United States
[email protected]

The North Canterbury fold and thrust belt in New Zealand lies in a region of transition between subduction on the Hikurangi subduction zone to the northeast and transpression on the Alpine fault to the southwest. The goal of this project is to quantify shortening and uplift in the region through construction of balanced cross sections and modeling of fault-related fold kinematics and to calculate uplift rates from dating of uplifted marine terraces. These methods will reveal how deformation in the region varies both temporally and spatially, which will be used to address such questions as what portion of plate boundary motion is accommodated by the structures in this region, how the region may have evolved in response to southward growth of the subduction zone, what the geometry of faults is in the basement rocks, and whether uplift can be explained by upper crustal shortening alone.

I have assembled existing structural data and maps from published papers and unpublished PhD theses and collected additional data in the field on structures of particular interest, and I have collected samples from several marine terraces for carbon dating. Further work in these areas as well as detailed GPS surveys across the terraces are also planned. The structural data will be used to construct multiple cross sections across the region and specific structures, while the terrace ages and elevations will provide uplift rates and indications of how structures have evolved over time.

AAPG Search and Discovery Article #90157©2012 AAPG Foundation 2012 Grants-in-Aid Projects