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The structural evolution of pull‐apart basins in response to changes in plate motion
Author(s) -
Farangitakis GeorgiosPavlos,
McCaffrey Ken J. W.,
Willingshofer Ernst,
Allen Mark B.,
Kalnins Lara M.,
Hunen Jeroen,
Persaud Patricia,
Sokoutis Dimitrios
Publication year - 2021
Publication title -
basin research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.522
H-Index - 83
eISSN - 1365-2117
pISSN - 0950-091X
DOI - 10.1111/bre.12528
Subject(s) - geology , tectonics , oblique case , slip (aerodynamics) , strike slip tectonics , rift , sedimentary basin , seismology , crust , structural geology , structural basin , sedimentary rock , shear (geology) , fault (geology) , pull apart basin , echelon formation , geometry , petrology , geophysics , geomorphology , paleontology , linguistics , philosophy , physics , mathematics , thermodynamics
Pull‐apart basins are structural features linked to the interactions between strike‐slip and extensional tectonics. Their morphology and structural evolution are determined by factors such as extension rate, the basin length/width ratio, and changes in extension direction. In this work, we investigate the effect of a change in the plate motion direction on a pull‐apart basin's structure, using analogue modelling experiments with a two‐layer ductile‐brittle configuration to simulate continental crust rheology. We initially impose orthogonal extension on an interconnected rift and strike‐slip system to drive pull‐apart development. Subsequently, we rotate the relative motion vector, imposing transtensional deformation and continuing with this new relative motion vector to the end of the experiment. To compare with natural examples, we analyse the model using seismic interpretation software, generating 3D fault structure and sedimentary thickness interpretations. Results show that the change in the direction of plate motion produces map‐view sigmoidal oblique slip faults that become normal‐slip when deformation adjusts to the new plate motion vector. Furthermore, sediment distribution is strongly influenced by the relative plate rotation, changing the locus of deposition inside the basin at each model stage. Finally, we compare our observations to seismic reflection images, sedimentary package thicknesses and fault interpretations from the Northern Gulf of California and find good agreement between model and nature. Similar fault arrays occur in the Bohai Basin in northern China, which suggests a rotational component in its evolution. More broadly, such similar structures could indicate a role for oblique extension and fault rotation in any pull‐apart basin.