Orogenic uplift and collapse, crustal thickness, fabrics and metamorphic phase changes: the role of eclogites

@article{Dewey1993OrogenicUA,
  title={Orogenic uplift and collapse, crustal thickness, fabrics and metamorphic phase changes: the role of eclogites},
  author={John Frederick Dewey and Paul D. Ryan and Torgeir B. Andersen},
  journal={Geological Society, London, Special Publications},
  year={1993},
  volume={76},
  pages={325 - 343}
}
Abstract Coesite-bearing eclogites in several deep crustal metamorphic assemblages now exposed in extensionally-collapsed orogens indicate the tectonic denudation of more than 90 km of crustal rocks and pre-collapsed crustal thicknesses of at least 120 km. For mountain ranges and orogenic plateaux up to 5 km in elevation and average crustal densities of about 2.8, crustal thickness cannot exceed about 80 km unless pre-shortening crustal/lithosphere thickness ratios were less than 0.135 or some… Expand

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TLDR
It is suggested that the deep arc crust must have primarily involved significant igneous accumulation of garnet–clinopyroxene (in proportions >75%) to have induced foundering of excised cumulate material at P > 1.2 GPa. Expand
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References

SHOWING 1-10 OF 81 REFERENCES
Thrust tectonics, deep structure and crustal subduction in the Alps and Himalayas
  • R. Butler
  • Geology
  • Journal of the Geological Society
  • 1986
The structural restoration of collision orogenic belts onto crustal templates provides important insights into the tectonic evolution, deep structure and amounts of plate convergence after theExpand
Uplift of deep crust during orogenic extensional collapse: A model based on field studies in the Sogn‐Sunnfjord Region of western Norway
The Western Gneiss Region (WGR) in Norway experienced high-pressure metamorphism during Silurian-Devonian continent-continent collision. The eclogite-bearing lower crust is separated from the middleExpand
Metamorphic consequences of crustal eclogite production in overthrust orogenic zones
Continental collision can produce crust of much greater than normal thickness in whose lower part eclogite facies conditions may pertain. The resulting density increase of ca. 0.3 Mg m−3 greatlyExpand
Eclogite formation and dynamics of crustal roots under continental collision zones
Field observations on deep parts of the root zone of the Caledonian orogen are combined with the geophysical data available for recent continental collision zones such as the Alps, to provide a modelExpand
Subduction and eduction of continental crust: major mechanisms during continent‐continent collision and orogenic extensional collapse, a model based on the south Norwegian Caledonides
During continental collision in the middle Silurian, the thickness of the lithosphere under the Caledonides of S. Norway was doubled by subduction of the western margin of Baltica, including theExpand
Eclogitization of lower crustal granulites by fluid migration through shear zones
The granulite facies assemblages of the anorthositic rocks of the Bergen Arcs (stable at 800–900°C and 10 kbar) have been transformed to eclogite facies assemblages (stable at 700–750°C and 16–19Expand
Petrological constraints and PT path of Devonian collapse tectonics within the Scandian mountain belt (Western Gneiss Region, Norway)
In Norway, post-Caledonian extension controlled the formation and sedimentation of Middle Devonian sedimentary basins. These ‘collapse basins’ were deposited along a low-angle extensional detachmentExpand
Very-high-pressure metamorphism in the western Alps: implications for subduction of continental crust
  • C. Chopin
  • Geology
  • Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences
  • 1987
The widespread occurrence of coesite and pure pyrope, the presence of several new mineral assemblages and new rock-forming minerals in common lithologies, but also crystal—chemical features such asExpand
Extensional collapse of orogens
Lithospheric extension is sited, preferentially, along orogenic belts because they have a thicker continental crust, contain structural inhomogeneities, and suffer extensional orogenic collapseExpand
Metamorphic evolution of the Eiksunddal eclogite complex. Western Norway, and some tectonic implications
The metamorphic evolution of the Western Gneiss Region of Norway (WGR) can be evaluated from examination of eclogites formed as an integral part of the gneiss terrain (ie. in situ). Petrologic dataExpand
...
1
2
3
4
5
...