Kattenhorn, S.A., McConnell, D.A. (1994)

-----

Analysis of outcrop-scale fault-related folds, Eagle Rock, Virginia


Southeastern Geology 34, 79-88.

Geometric and kinematic models of fault-related folds predict a direct relationship between fault angle and fold shape and imply specific sequences of deformation. Analysis of outcrop-scale structures from Eagle Rock, Virginia, reveal fault-fold configurations that depart from model predictions.

A displacement-distance diagram is used to show that a thrust ramp loses displacement both up- and down-dip. The ramp is interpreted to have initiated at an intermediate nucleation point and propagated in both directions. Layers were initially folded ahead of the fault tips and were subsequently cut by the fault, producing both a hanging wall anticline and a footwall syncline.

Deformation styles are influenced by the character of the sedimentary rocks (rock types, relative thickness, order of units), an observation that is not readily incorporated into models of fault-fold interaction. A series of small displacement faults imbricated a competent sandstone unit where it lies between thicker, incompetent units (high ductility contrast). The incompetent unit responded with disharmonic folding and thickness changes above and below the fault ramps.


-----

Citations:


This paper has been cited in the following 6 works:


Nicol, A., Gillespie, P.A., Childs, C., Walsh, J.J., 2002. Integrating 3-D seismic data, field analogs, and mechanical models in the analysis of segmented normal faults in the Wytch Farm oil field, southern England, United Kingdom. JOURNAL OF STRUCTURAL GEOLOGY 24: 709-727.

Hogan, J.P., Dunne, W.M., 2001. Calculation of shortening due to outcrop-scale deformation and its relation to regional deformation patterns. JOURNAL OF STRUCTURAL GEOLOGY 23: 1507-1529.

Kattenhorn, S.A., Pollard, D.D., 2001. Integrating 3-D seismic data, field analogs, and mechanical models in the analysis of segmented normal faults in the Wytch Farm oil field, southern England, United Kingdom. AAPG BULLETIN 85 (7): 1183-1210.

Cooke, M.L., Pollard, D.D., 1997. Bedding-plane slip in initial stages of fault-related folding. JOURNAL OF STRUCTURAL GEOLOGY 19: 567-581.

McConnell, D.A., Kattenhorn, S.A., Benner, L.M., 1997. Distribution of fault slip in outcrop-scale fault-related folds, Appalachian Mountains. JOURNAL OF STRUCTURAL GEOLOGY 19: 257-267.

Roering, J.J., Cooke, M.L., Pollard, D.D., 1997. Why blind thrust faults do not propagate to the Earth's surface: Numerical modeling of coseismic deformation associated with thrust-related anticlines. JOURNAL OF GEOPHYSICAL RESEARCH 102: 11,901-11,912.


-----

BACK