Vertical averages of rheology of the continental lithosphere: relation to thin sheet parameters

Sonder, Leslie J.; England, Philip

doi:10.1016/0012-821x(86)90134-2

Cited by 189 publications

(130 citation statements)

References 29 publications

Supporting

Mentioning

128

Contrasting

Unclassified

Order By: Relevance

“…A rheological exponent of n = 3 would be appropriate for a lithosphere whose vertically averaged rheology is dominated by the power law creep of olivine [Karato et al, 1986]. A somewhat greater value of n may be required if faults play a significant role in the effective rheological behavior of the lithosphere [Sonder and England, 1986], and we use n = 10 to represent an extreme example of this type. The above values of the Argand number were determined by Houseman and England [1986] as the values which produce the most realistic distribution of crustal thickness for the respective rheological exponents ofn = 3 and n = 10.…”

Section: Methodsmentioning

confidence: 99%

Geodynamics of the Tarim Basin and the Tian Shan in central Asia

Neil¹,

Houseman²

1997

Tectonics

141

View full text Add to dashboard Cite

Section: Methodsmentioning

confidence: 99%

Geodynamics of the Tarim Basin and the Tian Shan in central Asia

Neil¹,

Houseman²

1997

Tectonics

141

View full text Add to dashboard Cite

“…In the continental lithosphere, the localisation of tectonic activity is influenced by many factors: beyond the temporal and spatial deviations in the thermal state of the lithosphere (Sonder and England 1986;England 1987), the presence of old faults and shear zones are also essential factors . The formation of faults and shear zones is usually followed by a number of softening processes, which can cause substantial weakening both coincidentally with deformation and in the long-term.…”

Section: Possible Geodynamical Interpretationsmentioning

confidence: 99%

Localisation of ductile and brittle shear zones along the Szentlőrinc-1 well in the Mecsekalja Zone using quartz microstructural and well-log data

Skultéti

Tóth

2015

Acta Geod Geophys

View full text Add to dashboard Cite

Quartz is among the most common minerals in the Earth's crust and is stable within a wide range of temperature and pressure conditions. As its microstructure is sensitive to different deformation mechanisms, quartz may present information about the structural evolution of many different rock types. The Szentl} orinc-1 well with its drill cuttings brought to the surface from approximately 2 km depth provides an exclusive chance to investigate the shear zone beneath. The drill cutting collection includes only a few small rock grains, and more than 80 % of the material consists of tiny (\1 mm) single quartz grains. In this study, three microstructurally extreme quartz grain types were separated during microscopic analysis: grains with undulose extinction (U), grains with subgrains (S), and grains with recrystallized grains (R). Moreover, numerous microstructurally transitional grains were measured, which represent combinations of the above extremes. The characterisation of single quartz grain microstructures along the whole well enables identification and localisation of the ductile shear zones inside the crystalline complex. This information was combined with well-log data, which could provide information about the brittle deformation. Using these logs, brittle shear zones can be localised along the well. When comparing depths and extensions of the deformed horizons, a coincidence of the brittle and ductile zones becomes clear. This behaviour may suggest two different evolution schemes: it could be caused by primarily evolved softened regions, or it could be described by a detachment fault model.

show abstract

“…Influence of geomorphic processes on the mechanical behavior of a deforming orogen can assume at least two forms, both related to the integrated strength of the crust (ϭ F c , Sonder and England, 1986). First, crustal strength may be perturbed by the differential loading by existing topographic features.…”

Section: Mechanical Influence Of Topography and Exhumationmentioning

confidence: 99%

“…in which ⌬ BD is the differential stress at the base of the brittle layer (Sonder and England, 1986). The rapid decrease in shear resistance with temperature above ϳ 400°C limits any contribution to the integrated strength of the lower crust to that region directly below the brittle-ductile transition ( fig.…”

Section: Influence Of Exhumationmentioning

confidence: 99%

Mechanical links between erosion and metamorphism in Nanga Parbat, Pakistan Himalaya

Koons¹,

Zeitler²,

Chamberlain³

et al. 2002

American Journal of Science

152

129

View full text Add to dashboard Cite

ABSTRACT. The mechanics and petrological signature of a collisional mountain belt can be significantly influenced by topographic and erosional effects at the scale of large river gorges. The geomorphic influence on crustal scale processes arises from the effects of both stress localization due to existing topography, and also erosional removal of advected crustal mass. The shear stress concentration and normal stress amplification due to topographic gradients and loads divert strain away from existing topographic loads, while concentrating strain into topographic gaps. Efficient erosional removal of material within topographic gaps with widths of at least the thickness of the brittle crustal layer results in differential advection of crustal material. Concentrated exhumation within a gap leads to thermal thinning of the upper brittle layer of the crust, removing the highest strength part of the continental crust and significantly reducing the integrated crustal strength beneath the topographic gap. A rheological weak spot, triggered by efficient incision, grows in intensity as strain becomes increasingly concentrated within the weak region. The growth of extreme topography of an isolated massif requires that the process of creation of the massif is related to the weakening process and can result from the velocity pattern produced by erosionalrheological coupling. As a result, distinctive thermal/mechanical regions develop within the crust in response to these river-influenced velocity patterns and these regions impose a characteristic signature on material advecting through. The signal is one in which the region of highest topography is bracketed by two high-strain zones between which concentrated advection produces lozenges of sillimanite and dry melt stability approximately 20 kilometers beneath the summit. Above these lozenges is a thermal/mechanical boundary layer containing an active hydrothermal system driven by steep thermal, topographic and mechanical gradients. These thermal mechanical regions are fixed with respect to a crustal reference frame. Passage of rock beneath and through these regions under these conditions produces the distinctive petrology and structure of mantled gneiss domes and is recorded within the moving petrological reference frame. Such erosional-rheological coupling can explain the occurrence of some high-grade gneiss domes in ancient collisional belts as well as the presence of active metamorphic massifs at both ends of the Himalayan orogen.

show abstract

Vertical averages of rheology of the continental lithosphere: relation to thin sheet parameters

Cited by 189 publications

References 29 publications

Geodynamics of the Tarim Basin and the Tian Shan in central Asia

Geodynamics of the Tarim Basin and the Tian Shan in central Asia

Localisation of ductile and brittle shear zones along the Szentlőrinc-1 well in the Mecsekalja Zone using quartz microstructural and well-log data

Mechanical links between erosion and metamorphism in Nanga Parbat, Pakistan Himalaya

Contact Info

Product

Resources

About