TY - JOUR
T1 - The impact of oblique inheritance and changes in relative plate motion on the development of rift-transform systems
AU - Farangitakis , G. P.
AU - Heron, P. J.
AU - McCaffrey, K. J. W.
AU - van Hunen , J.
AU - Kalnins, Lara
N1 - LMK is supported by a Royal Society of Edinburgh Personal Research Fellowship funded by The Scottish Government.
PY - 2020/7/1
Y1 - 2020/7/1
N2 - In transform margins, oblique structural inheritance and plate motion vector changes have a direct impact on the margin's morphology and duration of transform activity. We investigate the effect of these two factors using numerical modelling. To simulate oblique inheritance in continental lithosphere, we model an initial rift-transform-rift configuration oriented at a range of angles (−45o to +45o) with respect to the extension direction. In a second suite of calculations, we first extend a rift-transform-rift system orthogonally and then vary the extension direction to simulate rotation of the far-field stress directions, and hence the relative plate motion. We found that transpressional deformation on the transform results in increased duration of fault activity and diffuse, longer transform zones at higher angles, while the opposite is true for the transtensional case. These observations are in good agreement with natural examples such as the Ungava Transform Zone, the Gulf of California and the Gulf of Aden, indicating that relative plate rotation plays an important role in the structural evolution of transform margins. Finally, we present a metric that links current transform margin morphology to past evolution.
AB - In transform margins, oblique structural inheritance and plate motion vector changes have a direct impact on the margin's morphology and duration of transform activity. We investigate the effect of these two factors using numerical modelling. To simulate oblique inheritance in continental lithosphere, we model an initial rift-transform-rift configuration oriented at a range of angles (−45o to +45o) with respect to the extension direction. In a second suite of calculations, we first extend a rift-transform-rift system orthogonally and then vary the extension direction to simulate rotation of the far-field stress directions, and hence the relative plate motion. We found that transpressional deformation on the transform results in increased duration of fault activity and diffuse, longer transform zones at higher angles, while the opposite is true for the transtensional case. These observations are in good agreement with natural examples such as the Ungava Transform Zone, the Gulf of California and the Gulf of Aden, indicating that relative plate rotation plays an important role in the structural evolution of transform margins. Finally, we present a metric that links current transform margin morphology to past evolution.
U2 - https://doi.org/10.1016/j.epsl.2020.116277
DO - https://doi.org/10.1016/j.epsl.2020.116277
M3 - Article
SN - 0012-821X
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
ER -