Roof Thrust Duplex

A duplex consists of a series of imbricate faults that are asymptotic to a roof thrust and a floor thrust.

Roof thrust duplex.

The sicilian collisional complex is a well exposed fold and thrust belt ftb belonging to the apennine maghrebian chain developed along the africa europe plate margin fig. A dictionary of earth sciences dictionary. Thrust duplex duplexes occur where there are two decollement levels close to each other within a sedimentary sequence such as the top and base of a relatively strong sandstone layer bounded by two relatively weak mudstone layers. A duplex as a reminder is an array of thrust horses bounded by a floor thrust i e.

Duplex is a thrust sheet mass which is bounded by a fioor thrust and a roof thrust often duplex structures are imbricated. The central appalachian fold thrust belt is characterized by a passive roof duplex and as such the total shortening accom modated by the sequence above the roof thrust must equal the shortening. The fault bound bodies of rock in the duplex are called horses. In a thrust envi ronment the structural association is.

You can also visit the homepage and enjoy the wonderful photographies with very good examples from many places around the planet. Roof thrust in a duplex system the structurally highest bounding thrust surface which joins the floor thrust at the leading and trailing edges of the duplex. The rock masses bounded by these faults are calledhorses and the entire structural association is a duplex. Depending on the final orientations of the imbricate faults and the final position of the branch lines a duplex may be hinterland dipping foreland dipping or an antiformal stack.

In this setting the roof sequence frequently develops passive roof duplexes banks and warburton 1986. Boyer and elliott 1982 state that the roof thrust of a duplex is initiated as a major thrust. Blind thrusts are those below the erosion surface but their presence is indicated by shortening in the overlying sequence which is achieved by disharmonic. Duplexes have a variety of forms and sizes depending on the amount of displacement of the individual horses.

Also upper and lower detachments have been described in a similar context for fold duplex structures dahlstrom 1969a. Sole thrust at the base and by a roof thrust at the top mcclay 1992. Source for information on roof thrust.