What is fault-propagation fold?
Abstract. Fault-propagation folding, a common folding mechanism in fold and thrust belts, occurs when a propagating thrust fault loses slip and terminates upsection by transferring its shortening to a fold developing at its tip.
What is the difference between a fault-propagation fold and a fault-bend fold?
Fault-bend folds tend to have forelimbs and backlimbs that are relatively symmetric in limb width and dip, while fault-propagation folds are characterized by long, gently dipping backlimbs and narrow, steeply dipping forelimbs.
What is the fold and fault?
Folds constitute the twists and bends in rocks. Faults are planes of detachment resulting when rocks on either side of the displacement slip past one another. The type of strain (deformation) that develops in a rock depends on the tectonic force.
What is a thrust fault system?
thrust fault – a dip-slip fault in which the upper block, above the fault plane, moves up and over the lower block. This type of faulting is common in areas of compression, such as regions where one plate is being subducted under another as in Japan.
Which type of fold is associated with a fault line?
Fault propagation folds or tip-line folds are caused when displacement occurs on an existing fault without further propagation. In both reverse and normal faults this leads to folding of the overlying sequence, often in the form of a monocline.
What causes folding?
Folding- Folding occurs when tectonic processes put stress on a rock, and the rock bends, instead of breaking. This can create a variety of landforms as the surfaces of the folded rocks are eroded. Anticlines are folds shaped like an arch, and synclines are shaped like the letter ‘U.
When does fault propagation occur in a fold?
Fault-propagation folding, a common folding mechanism in fold and thrust belts, occurs when a propagating thrust fault loses slip and terminates upsection by transferring its shortening to a fold developing at its tip.
Which is an example of a fault bend fold?
These two models illustrate typical structures developed in fold and thrust belts. The photograph below shows a fault-bend fold from the Eohimalayan Fold and Thrust belt developed in Jurassic Kyoto Limestone, Spiti Valley, NW Himalaya, India (photograph by Gerhard Wiesmayr, Vienna).
How are faults folded in geometry and kinematics?
Geometry and kinematics of fault-propagation folding. It is here proposed that some thrust faults do not propagate rapidly as clean fractures but rather propagate gradually as slip accumulates. At each instant during propagation, slip goes to zero at the fault tip and is consumed in folding.
Why do thrust faults not propagate as clean fractures?
It is here proposed that some thrust faults do not propagate rapidly as clean fractures but rather propagate gradually as slip accumulates. At each instant during propagation, slip goes to zero at the fault tip and is consumed in folding.