4:45 PM - 5:00 PM
[PPS08-24] Importance of Fault-Crater Interactions in Understanding Planetary Subsurface Faults
Keywords:Crater, Fault, Angle, Direction, Planetary bodies
Understanding faults on planetary surfaces such as the Moon, Mars, and Mercury has always
been a complex and challenging endeavour. Many studies have conducted morphological
analyses and numerical simulations to investigate the geometry and kinematics of subsurface
compressional faults. Examples of these compressional faults include wrinkle ridges and
lobate scarps. Wrinkle ridges display a variety of morphologies, such as symmetric ridges,
arch-style ridges, and double ridges. These morphological variations are linked to different
fault geometries, including buckle folds, conjugate thrust faults, fault-bend folds, kink-type
fault-propagation folds, main thrusts with backthrusts, and listric thrust faults. In contrast,
lobate scarps are characterized by a steeply sloping scarp face and a gently sloping back scarp
and are associated with planar thrust faults. In addition to studying the morphologies
associated with these faults, earlier studies have investigated fault geometry and kinematics
by analyzing faults that crosscut impact craters, such as at crater walls and through variations
in the circularity of crater rims on the hanging wall and footwall. These studies highlight how
fault-crater interactions can provide valuable insights into fault geometries and their
kinematics.
Building on these previous studies, our research specifically examines how the angle and
position of fault-crater interactions affect crater deformation patterns. Additionally, we
predicted the direction of fault movement, estimated the fault angle from these interactions,
and explored how this approach can be applied more broadly to understand local and regional
fault systems on planetary bodies. Our study utilizes numerical simulations; we used ANSYS
2019 software to investigate fault-crater interactions through Finite Element Analysis (FEA).
The model incorporated material properties with a Young's modulus of ~30 GPa and a
Poisson's ratio of 0.3. We carried out the simulation for a 100-meter-diameter crater with a
depth of 20 m, with a blind fault located 1 m beneath the crater. We modelled a single fault
system and simulated blind fault interactions with the crater at angles of 10°, 30°, 60°, and
90° at both the crater floor and wall. The geometry was meshed with 2 m divisions, and an
external force was applied to the hanging wall, counterbalanced by fixed supports on the
footwall.
The outcomes of our investigation reveal that the shape of the fault-crater intersection
evolves, transitioning from a concave form at low-angle intersections to gradually becoming
a straight line at 90-degree intersections. This concavity provides insight into fault
movement, with the concave side indicating the direction of fault slip or displacement. Such
interactions are observed globally on the Moon, Mercury, and other planetary bodies,
offering valuable insights into fault systems at varying angles. Additionally, we were able to
estimate the fault angles within ±5° and predict the presence of backthrusts at a regional
scale.
been a complex and challenging endeavour. Many studies have conducted morphological
analyses and numerical simulations to investigate the geometry and kinematics of subsurface
compressional faults. Examples of these compressional faults include wrinkle ridges and
lobate scarps. Wrinkle ridges display a variety of morphologies, such as symmetric ridges,
arch-style ridges, and double ridges. These morphological variations are linked to different
fault geometries, including buckle folds, conjugate thrust faults, fault-bend folds, kink-type
fault-propagation folds, main thrusts with backthrusts, and listric thrust faults. In contrast,
lobate scarps are characterized by a steeply sloping scarp face and a gently sloping back scarp
and are associated with planar thrust faults. In addition to studying the morphologies
associated with these faults, earlier studies have investigated fault geometry and kinematics
by analyzing faults that crosscut impact craters, such as at crater walls and through variations
in the circularity of crater rims on the hanging wall and footwall. These studies highlight how
fault-crater interactions can provide valuable insights into fault geometries and their
kinematics.
Building on these previous studies, our research specifically examines how the angle and
position of fault-crater interactions affect crater deformation patterns. Additionally, we
predicted the direction of fault movement, estimated the fault angle from these interactions,
and explored how this approach can be applied more broadly to understand local and regional
fault systems on planetary bodies. Our study utilizes numerical simulations; we used ANSYS
2019 software to investigate fault-crater interactions through Finite Element Analysis (FEA).
The model incorporated material properties with a Young's modulus of ~30 GPa and a
Poisson's ratio of 0.3. We carried out the simulation for a 100-meter-diameter crater with a
depth of 20 m, with a blind fault located 1 m beneath the crater. We modelled a single fault
system and simulated blind fault interactions with the crater at angles of 10°, 30°, 60°, and
90° at both the crater floor and wall. The geometry was meshed with 2 m divisions, and an
external force was applied to the hanging wall, counterbalanced by fixed supports on the
footwall.
The outcomes of our investigation reveal that the shape of the fault-crater intersection
evolves, transitioning from a concave form at low-angle intersections to gradually becoming
a straight line at 90-degree intersections. This concavity provides insight into fault
movement, with the concave side indicating the direction of fault slip or displacement. Such
interactions are observed globally on the Moon, Mercury, and other planetary bodies,
offering valuable insights into fault systems at varying angles. Additionally, we were able to
estimate the fault angles within ±5° and predict the presence of backthrusts at a regional
scale.