Fault
Propagation Folding on the Central Basin Platform, West Texas
Blumentritt, Charles H.1,
Kurt J. Marfurt1, Michael Murphy1 (1) University of Houston, Houston, TX
We use 3-D seismic data to define the
three dimensional geometry of a fault block in the Central Basin Platform, west
Texas. The fault block lies
east of the Fort Stockton uplift and is bounded
by two north-striking basement involved high angle reverse faults and limited
to the north and south by a tear fault and a monocline. Deformation associated
with the basement faults is characterized by faulted strata at deep structural
levels and related folding at shallow levels. Asymmetric fold geometries
indicate the reverse faults are east-directed and root deeply into Precambrian
crystalline basement. No evidence of significant strike-slip faulting was found
along basement reverse faults. Along strike to the south, the fold-fault system
forms a monocline, while to the north it merges with an east-west striking tear
fault that shows left-lateral oblique slip of offset stratigraphic
horizons and small-scale structures. Lineaments determined from volumetric
curvature data indicate counter-clockwise, vertical axis rotation of the
basement fault block.
2-D forward models of our structural
interpretation were constructed to assess the geometry and kinematics of
deformation. Our results show that deformation can be explained by a
fault-propagation folding model that incorporates trishear
theory; both the geometry and magnitude of displacement along basement-involved
faults varies along strike; and the magnitude of slip along basement reverse
faults broadly correlates with that along basement tear faults suggesting the
two are linked.