Relationship of spaced cleavage to folds and thrusts in the Idaho-Utah-Wyoming thrust belt

Spatial and temporal variation in penetrative strain during compression: Insights from analog models

“…Measured amounts of penetrative strain range from 2% to 30%, where the larger end of this range may form a significant component of the total shortening (Engelder and Engelder, 1977;Engelder, 1979;Mitra and Yonkee, 1985;Wiltschko et al, 1985;Craddock and van der Pluijm, 1989;Mitra, 1994;Whitaker and Bartholomew, 1999;Sans et al, 2003;Koyi et al, 2004;Weil and Yonkee, 2009). Penetrative strain amount appears to decay away from the developing thrust front (Craddock and van der Pluijm, 1989;Koyi, 1995).…”

“…Different mechanisms (intravs. intergranular) may record different amounts of penetrative strain in a system; thus, the total penetrative strain must be estimated as a sum of components occurring in any given unit or thrust sheet (Groshong, 1975;Engelder, 1979;Mitra and Yonkee, 1985;Wiltschko et al, 1985;Mitra, 1994;Hogan and Dunne, 2001;Sans et al, 2003).…”

Spatial and Temporal Variation in Penetrative Strain During Compression: Insights From Analog Models

“…Mitra (1994) further showed that internal strains in the frontal thrust sheets are smaller than the internal strains in the hinterland thrust sheets. Typically, the development of penetrative strain-related features is considered to be a process that occurs early in the deformation process, before the development of macroscale structures (e.g., Geiser and Engelder, 1983;Mitra and Yonkee, 1985;Wiltschko et al, 1985;Henderson et al, 1986;Dean et al, 1988;Tavarnelli, 1997;Whitaker and Bartholomew, 1999;Weil and Yonkee, 2009), sometimes with a relationship to the developing thrust ramp (Fischer and Coward, 1982). Some authors have recognized multiple potential episodes of layer-parallel shortening (Geiser and Engelder, 1983;Gray and Mitra, 1993).…”

“…Penetrative strain can include layer-parallel strain (defined strictly as the maximum contractional strain accumulated parallel to layering; Groshong, 1975), and later strains that are imposed horizontally on layers that are no longer horizontal (Couzens et al, 1993;Mitra and Yonkee, 1985). On the grain scale, penetrative strain may be accommodated by a combination of intragranular deformation such as twinning, dislocation glide and creep, or the development of other strain fabrics, and intergranular processes such as stylolitization, cleavage development, or grain impingement (Groshong, 1975;Engelder and Engelder, 1977;Engelder, 1979;Henderson et al, 1986;Onasch, 1993;Tavarnelli, 1997).…”

Overburden-Induced Flattening Structure in the Himalaya: Mechanism and Implication

“…Small-scale structures and their tectonic implications are established from different FTBs like Alpine orogeny 2 , Caledonides 3 , Sevier 4 , Himalaya [5][6][7][8][9] and Zagros 10 , where small-scale folds and other tectonic structures are common. The genesis of these structures is related with the emplacement of the thrust sheets and are formed in successive stages of progressive deformation during the formation of the FTB [8][9][10][11] .…”