Three-dimensional folding
Insights into fold growth using fold-related joint patterns and mechanical stratigraphy 

Savage, Heather, Shackleton, J. Ryan, Michele L. Cooke, and Jeffrey J. Riedel, 2010. Insights into fold growth using fold-related joint patterns and mechanical stratigraphy, Journal of Structural Geology, vol. 32, 1466-1475, doi:10.1016/j.jsg.2010.09.004.

start fracs

Lateral fold growth can be recorded in joint orientations at fold terminations. Analysis of the mechanical stratigraphy of the folded layers elucidates the relative timing at which beds fractured. Prediction of joint orientation from curvature analysis at fold terminations should include the stresses on both the top and bottom of the folded layer. Joint patterns at Sheep Mountain Anticline, WY, USA, indicate that this structure grew laterally.

Interaction among faults and influence on folding

Mechanical model of two interacting faults

Savage, Heather M. and Michele L. Cooke. 2004. An investigation into the role of fault interaction on fold pattern, Journal of Structural Geology, vol. 26, pp 905-917. (PDF)

Overlying fold shape (purple contours) depends on interaction among subsurface faults (red lines).


Is consideration of fold growth important for predicting subsurface fracture patterns?

Images and animation of Three-dimesional fold growth

See Ryan Shackleton's webpage for more information

Three-dimensional growth of Sant Corneli Anticline, Spain

We mapped fractures at Sant Corneli anticline, an EW trending non-cylindrical, fault-related anticline in the Spanish Pyrenees. Fracture mapping in syn-tectonic strata directly links fold-related fracturing to fold evolution because the relationship of fractures to syn-tectonic strata can constrain structural timing. Rather than using absolute fracture orientation as a primary means of grouping fracture sets, we used relative fracture timing, mineral fill, fracture size (length and height), and orientation with respect to bed strike to delineate five bed-orthogonal fracture sets that we interpret to be associated with folding and faulting events. We observe several early sets of joints with calcite fill (J1, J2, J3) many of which are interpreted to be related to fold axis perpendicular normal faulting of the anticline. Two late-stage joint sets with associated iron oxide mineralization in the surrounding wall rock (J4, J5) are oblique to bedding, maintain orientation with respect to bed strike, and are interpreted to result from flexure of the anticline. We infer the timing of J4/J5 jointing relative to syn-tectonic events. This research demonstrates how fracture studies that integrate syn-tectonic strata and distinguish fracture sets on the basis of multiple characteristics can better constrain the timing of fracturing relative to regional deformation events.

Shackleton, J. Ryan, Michele L Cooke, Jaume Verges and Toni Simo, 2011. Temporal constraints on fracturing associated with fault-related folding at Sant Corneli anticline, Spanish Pyrenees, Journal of Structural Geology, vol. 33, 5-19, doi:10.1016/j.jsg.2010.11.003.

See Ryan Shackleton's web page for more

joints at san corneli

Comparison of kinematic and mechanical models of folding

Savage and Cooke, 2003. Can flat-ramp-flat fault geometry be inferred from fold shape?: A comparison of kinematic and mechanical folds, Journal of Structural Geology, vol 25, Pages 2023-2034 (pdf)