The deep structure of the central Alps inferred from both geophysical and geological data

Laubscher, H. P.

doi:10.1111/j.1365-3121.1990.tb00129.x

Cited by 9 publications

(4 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4 is oversimplified, especially in the internal and deep tectonic environments where ductile deformation may generate very complicated geometries (e.g. Moore and Wheeler, 1978;Scholl et al, 1980;Moore, Watkins and Shipley, 1981;Boyer and Elliott, 1982;Cowan, 1985;Ramsay and Huber, 1987;von Huene, Suess et al, 1988;Merle and Guillier, 1989;von Huene and Culotta, 1989;Laubscher, 1990;Pfiffner et al, 1990; von Huene and Lallemand, 1990;Butler, 1992;McClay, 1992 and references therein).…”

Section: Oftkemantlem Thrustbelts (Oftypea) Related T O S U B D~f O mentioning

confidence: 99%

Main differences between thrust belts

Doglioni

1992

Terra Nova

103

View full text Add to dashboard Cite

It is useful to differentiate between thrust belts that are related to east@)-dipping or westo-dipping subduction. More precisely, these either follow or resist the overall 'eastward' mantle flow detected by the hot-spot reference frame. Because of the overall 'westward' drift of the lithosphere we find in E-dipping subduction that the basal decollement underlying the eastern plate reaches the surface and involves deep crustal rocks. With W-dipping subduction, however, we find that the basal decollement of the eastern plate is warped as well as subducted. Consequently thrust belts related to E-(or NE-) dipping subduction show conspicuous structural and morphologic relief, involve deep crustal rocks, and are associated yith shallow foredeeps. On the other hand, thrust belts related to W-(or SW-) dipping subduction show relatively low structural and morphological relief, involve only shallow upper crustal rocks and are associated with deep foredeeps as well as back-arc extension. The accretionary wedge-foredeep-back-arc basin association is visualized as'an overall eastward propagating tectonic wave. The accretionary wedge forms in the frontal parts and generally below sea-level. This is followed by forward migrating extension that Struct. Ceol., 14 (I), 29-40. Cadek 0. and Ricard Y. (1992) Toroidd Poloidal Energy Partitioning and Global Lithospheric Rotation during Cenozoic Time, in press. Cadet J.P. and Charvet J. (1983) From Subduction to Paleosubductions in Northem Japan. In: Acnetion Tectonics in the Cimm-Pacific Regions (ed. by Hashimoto, M. and Uyeda, S.), pp. 135-148. TERRAPUB, Tokyo. CassanoE., AnelliL.,FicheraR. andCap pelli V. (1986) Pianura Padana, Interpretazione integrata di dati geofisia e geologia, Agip, 73" Cngr. Soc. &I. It., Rom, 1-22. Castellarin A., Eva C., Giglia G. and Vai G.B. (1985) Analisi strutturale del Fronte Appenninico Padano, G h l e Chamell J.E.T., Oldow J.S., Catalano R. and D'Argenio B. (1990) Paleomagn e t i d y determined rotations in the western Sicilian fold and thrust belt, Tectonics, 9 (4), 641-660. Chopin C. (1984) Coesite and pure pyrope in high grade blueschists of the Western Alps: A first record and some consequences, Contr. Miner. Petrol, 86, Geol., 14,337-381. mic~, Mkn. SOC. $01. Fr., 156,289-302. 219-245.

show abstract

Section: Oftkemantlem Thrustbelts (Oftypea) Related T O S U B D~f O mentioning

confidence: 99%

Main differences between thrust belts

Doglioni

1992

Terra Nova

103

View full text Add to dashboard Cite

show abstract

“…Considered together, the geological data summarized in previous works (e.g. Wezel, 1986;Laubscher, 1990) lead the present writer to believe that both the Ampferer and Benioff zones. (Bally and Snelson, 1980) could represent the edges of a vast funnel which is diagnostic of a mantle 'anomaly'.…”

Section: Mobile Megashear Belts and 'Mantle Chimneys'mentioning

confidence: 63%

From high plateaux to marginal basins: the active role of the mantle

Wezel

1992

Terra Nova

View full text Add to dashboard Cite

Current geodynamic models pose many serious problems for the description of continental tectonic processes, Serious difficulties arise also in the description of some of the ocean basins. Deformation of the Earth's crust appears to be concentrated along several mobile megashear belts. It is proposed that these could be the surficial expression of ‘mantle chimneys’ which extend to great depths. Within these structures, post orogenic high plateaux form, and as time passes these develop a central depression enclosed within arcs or indeed full‐scale rings of mountains. The enlargement and deepening over time of the back‐arc depression occurs in concert with the radial migration of a ‘topographic wave’. In this respect, the following structures represent different phases in an evolutionary sequence: (a) the Tibetan Plateau, (b) the North American Cordillera, and (c) the Tyrrhenian Basin and Calabrian Arc. The development of this succession reflects a particularly high degree of activity in the mantle, in which diapiric rising of asthenospheric matter elevates the land and causes tensional rifting. The resulting centrifugal movement of the mantle melt results in crustal foundering and engulfment of the area behind the arc, which thus becomes susceptible to the subsequent processes of com‐pressional deformation.

show abstract

“…Within the actual collision zone only subduction of the denser mantle lithosphere occurs. This assumption is reasonable for the Neoalpine orogeny as there was no or negligible conversion of subducted crustal into mantle material (Laubscher 1990). The base of the lithosphere, i.e.…”

Section: Large-scale Tectonic Mass Displacements I N T H E Neoalpine mentioning

confidence: 99%

“…In this algorithm, the crust-mantle boundary is supposed to represent a petrological boundary deforming under the implied mass-displacement field. This assumption is reasonable for the Neoalpine orogeny, as there was no or negligible conversion of crustal into mantle material, and vice versa (Laubscher 1990). The lithosphere-asthenosphere boundary, although migrating with depth due to tectonic movements, is thermally defined as the intersection of the geotherm with the wet solidus of lherzolite (Wyllie 1987).…”

Section: Thermokinematic Modelmentioning

confidence: 99%

A Lithospheric Cross-Section Through the Swiss Alps-I. Thermokinematic Modelling of the Neoalpine Orogeny

Okaya

Freeman

Kissling

et al. 1996

Geophysical Journal International

View full text Add to dashboard Cite

S U M M A R YIn this paper we develop a forward 2-D thermokinematic model to investigate the Neoalpine 35-0 Ma phase of orogeny along the European Geotraverse (EGT) through the Swiss Alps on a crustal and lithospheric scale. Using a divergence-free kinematic model (div v = 0), we define mass displacements, which subsequently serve as input to a transient thermal model. The thermal model uses critically assessed material parameters and accounts for the depth dependeice of the thermal properties in processes such as crustal thickening and mantle-lithospheric subduction. Based on the presentday density pattern of the deep seismic image and estimated exhumation and shortening rates, we derive, in a first modelling step, a mass-displacement field describing the Neoalpine orogeny as a uniform process in time. In a second-thermal-modelling step, this kinematic scenario is further refined by modelling the non-uniform cooling histories of the southern Lepontine in the Penninic domain. For that purpose we adopt lithospheric shortening rates-and consequently exhumation rates-to agree with total Neoalpine shortening, while keeping the geometry of the kinematic model fixed. The resultant thermokinematic model reflects the main characteristics of Neoalpine tectonics, and shows a good overall agreement with combined geological and geophysical data. The asymmetric feature of the present-day tectonic structure along the profile is strongly reflected in the thermal structure of the lithosphere. This demonstrates the need for a kinematic model to investigate the deep-temperature field in active tectonic provinces. For further refinement of the model, the amounts of shortening have to be more precisely estimated, and a higher spatial density in geochronological and metamorphic data is required. Furthermore, surface heat-flow values are, up to now, too uncertain to constrain the predicted surface heat flow. In summary, our results show that we need, in particular, data constraining the horizontal component of the tectonic and thermal evolution. The results of the Neoalpine orogeny modelling demonstrate that the presented thermokinematic procedure yields a good first-order approximation to investigate crustal-scale and lithospheric processes. We conclude, therefore, that the approach presented provides the potential for application not only to continent

show abstract

The deep structure of the central Alps inferred from both geophysical and geological data

Cited by 9 publications

References 20 publications

Main differences between thrust belts

Main differences between thrust belts

From high plateaux to marginal basins: the active role of the mantle

A Lithospheric Cross-Section Through the Swiss Alps-I. Thermokinematic Modelling of the Neoalpine Orogeny

Contact Info

Product

Resources

About