Abstract
Marine terraces on growing fault-propagation folds provide valuable insight into the relationship between fold kinematics and uplift rates, providing a means to distinguish among otherwise non-unique kinematic model solutions. Here, we investigate this relationship at two locations in North Canterbury, New Zealand: the Kate anticline and Haumuri Bluff, at the northern end of the Hawkswood anticline. At both locations, we calculate uplift rates of previously dated marine terraces, using DGPS surveys to estimate terrace inner edge elevations. We then use Markov chain Monte Carlo methods to fit fault-propagation fold kinematic models to structural geologic data, and we incorporate marine terrace uplift into the models as an additional constraint. At Haumuri Bluff, we find that marine terraces, when restored to originally horizontal surfaces, can help to eliminate certain trishear models that would fit the geologic data alone. At Kate anticline, we compare uplift rates at different structural positions and find that the spatial pattern of uplift rates is more consistent with trishear than with a parallel-fault propagation fold kink-band model. Finally, we use our model results to compute new estimates for fault slip rates (~ 1–2 m/ka at Kate anticline and 1–4 m/ka at Haumuri Bluff) and ages of the folds (~ 1 Ma), which are consistent with previous estimates for the onset of folding in this region. These results are consistent with previous work on the age of onset of folding in this region, provide revised estimates of fault slip rates necessary to understand the seismic hazard posed by these faults, and demonstrate the value of incorporating marine terraces in inverse fold kinematic models as a means to distinguish among non-unique solutions.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 195-219 |
| Number of pages | 25 |
| Journal | Tectonophysics |
| Volume | 724-725 |
| DOIs | |
| State | Published - Jan 31 2018 |
Fingerprint
All Science Journal Classification (ASJC) codes
- Geophysics
- Earth-Surface Processes
Cite this
}
Uplift rates of marine terraces as a constraint on fault-propagation fold kinematics : Examples from the Hawkswood and Kate anticlines, North Canterbury, New Zealand. / Oakley, David O.S.; Fisher, Donald M.; Gardner, Thomas W.; Stewart, Mary Kate.
In: Tectonophysics, Vol. 724-725, 31.01.2018, p. 195-219.Research output: Contribution to journal › Article
TY - JOUR
T1 - Uplift rates of marine terraces as a constraint on fault-propagation fold kinematics
T2 - Examples from the Hawkswood and Kate anticlines, North Canterbury, New Zealand
AU - Oakley, David O.S.
AU - Fisher, Donald M.
AU - Gardner, Thomas W.
AU - Stewart, Mary Kate
PY - 2018/1/31
Y1 - 2018/1/31
N2 - Marine terraces on growing fault-propagation folds provide valuable insight into the relationship between fold kinematics and uplift rates, providing a means to distinguish among otherwise non-unique kinematic model solutions. Here, we investigate this relationship at two locations in North Canterbury, New Zealand: the Kate anticline and Haumuri Bluff, at the northern end of the Hawkswood anticline. At both locations, we calculate uplift rates of previously dated marine terraces, using DGPS surveys to estimate terrace inner edge elevations. We then use Markov chain Monte Carlo methods to fit fault-propagation fold kinematic models to structural geologic data, and we incorporate marine terrace uplift into the models as an additional constraint. At Haumuri Bluff, we find that marine terraces, when restored to originally horizontal surfaces, can help to eliminate certain trishear models that would fit the geologic data alone. At Kate anticline, we compare uplift rates at different structural positions and find that the spatial pattern of uplift rates is more consistent with trishear than with a parallel-fault propagation fold kink-band model. Finally, we use our model results to compute new estimates for fault slip rates (~ 1–2 m/ka at Kate anticline and 1–4 m/ka at Haumuri Bluff) and ages of the folds (~ 1 Ma), which are consistent with previous estimates for the onset of folding in this region. These results are consistent with previous work on the age of onset of folding in this region, provide revised estimates of fault slip rates necessary to understand the seismic hazard posed by these faults, and demonstrate the value of incorporating marine terraces in inverse fold kinematic models as a means to distinguish among non-unique solutions.
AB - Marine terraces on growing fault-propagation folds provide valuable insight into the relationship between fold kinematics and uplift rates, providing a means to distinguish among otherwise non-unique kinematic model solutions. Here, we investigate this relationship at two locations in North Canterbury, New Zealand: the Kate anticline and Haumuri Bluff, at the northern end of the Hawkswood anticline. At both locations, we calculate uplift rates of previously dated marine terraces, using DGPS surveys to estimate terrace inner edge elevations. We then use Markov chain Monte Carlo methods to fit fault-propagation fold kinematic models to structural geologic data, and we incorporate marine terrace uplift into the models as an additional constraint. At Haumuri Bluff, we find that marine terraces, when restored to originally horizontal surfaces, can help to eliminate certain trishear models that would fit the geologic data alone. At Kate anticline, we compare uplift rates at different structural positions and find that the spatial pattern of uplift rates is more consistent with trishear than with a parallel-fault propagation fold kink-band model. Finally, we use our model results to compute new estimates for fault slip rates (~ 1–2 m/ka at Kate anticline and 1–4 m/ka at Haumuri Bluff) and ages of the folds (~ 1 Ma), which are consistent with previous estimates for the onset of folding in this region. These results are consistent with previous work on the age of onset of folding in this region, provide revised estimates of fault slip rates necessary to understand the seismic hazard posed by these faults, and demonstrate the value of incorporating marine terraces in inverse fold kinematic models as a means to distinguish among non-unique solutions.
UR - http://www.scopus.com/inward/record.url?scp=85044641766&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85044641766&partnerID=8YFLogxK
U2 - 10.1016/j.tecto.2017.12.021
DO - 10.1016/j.tecto.2017.12.021
M3 - Article
AN - SCOPUS:85044641766
VL - 724-725
SP - 195
EP - 219
JO - Tectonophysics
JF - Tectonophysics
SN - 0040-1951
ER -