ALBERT

Description: Continental tectonics, and the formation of mountain belts, do not adhere to the plate tectonic paradigm (Molnar 1988). Mountain belts at plate boundaries are areas of diffuse deformation in which geologists have recognized that not only are the plates not rigid (Gordon 1998), but parts of the lithosphere (e.g. upper crust) are moving laterally with respect to other parts (e.g. lower crust), such as in thrust belts (Bally et al. 1966). An exciting development in tectonics is the detailed investigation of the behaviour of continental crust during orogenesis. In particular, the role of coupling (attachment) or decoupling (detachment) of the lithospheric layers during continental deformation has significant implications for all aspects of modern and ancient tectonics. The recognition of regional detachments or decollements, an idea developed in foreland fold and thrust belts, was the first major contribution to our understanding of the vertical stratification in orogenic belts. Elucidation of the structure of foreland fold and thrust belts in the external parts of orogens by the development of the techniques of balanced cross-section construction (Price 1981, 1986) and deep seismic reflection profiling (e.g. Mueller et al. 1980) showed that foreland thrust systems are typically think-skinned and bounded at depth by a basal detachment, decollement or sole thrust. Shortening in the external parts of cordilleran and collisional orogens was taken up by folding and thrusting above a basement which remained essentially undeformed and part of the foreland (e.g. Bally et al. 1966). Balanced cross-section techniques were developed and refined in the Alberta ... This 250-word extract was created in the absence of an abstract.