scholarly journals The Alps 2: Controls on crustal subduction and (ultra)high-pressure rock exhumation in Alpine-type orogens

2014 ◽  
Vol 119 (7) ◽  
pp. 5987-6022 ◽  
Author(s):  
Jared P. Butler ◽  
Christopher Beaumont ◽  
Rebecca A. Jamieson
Keyword(s):  
High Pressure ◽  
Ultra High Pressure ◽  
The Alps

Under Pressure: High-Pressure Metamorphism in the Alps

Elements ◽  
2021 ◽  
Vol 17 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Lucie Tajčmanová ◽  
Paola Manzotti ◽  
Matteo Alvaro
Keyword(s):  
High Pressure ◽  
Structural Data ◽  
Metamorphic Rocks ◽  
Lithostatic Pressure ◽  
Mineral Inclusion ◽  
Crustal Material ◽  
Local Pressure ◽  
Ultra High Pressure ◽  
Mechanical Models ◽  
The Alps

The mechanisms attending the burial of crustal material and its exhumation before and during the Alpine orogeny are controversial. New mechanical models propose local pressure perturbations deviating from lithostatic pressure as a possible mechanism for creating (ultra-)high-pressure rocks in the Alps. These models challenge the assumption that metamorphic pressure can be used as a measure of depth, in this case implying deep subduction of metamorphic rocks beneath the Alpine orogen. We summarize petro-logical, geochronological and structural data to assess two fundamentally distinct mechanisms of forming (ultra-)high-pressure rocks: deep subduction; or anomalous, non-lithostatic pressure variation. Furthermore, we explore mineral-inclusion barometry to assess the relationship between pressure and depth in metamorphic rocks.

Subduction initiation and subsequent burial-exhumation of (ultra)high-pressure rock

2021 ◽  
Author(s):  
Stefan Markus Schmalholz ◽  
Lorenzo Candioti ◽  
Joshua Vaughan-Hammon ◽  
Thibault Duretz
Keyword(s):  
High Pressure ◽  
Subduction Zones ◽  
Conceptual Models ◽  
Passive Margin ◽  
Far Field ◽  
Subduction Initiation ◽  
Ultra High Pressure ◽  
Orogenic Wedge ◽  
The Alps ◽  
Marine Basin

<p>Subduction zones are one of the main features of plate tectonics, they are essential for geochemical cycling and are often a key player during mountain building. However, several processes related to subduction zones remain elusive, such as the initiation of subduction or the exhumation of (ultra)high-pressure rocks.</p><p>Collision orogens, such as the European Alps or Himalayas, provide valuable insight into long-term subduction zone processes and the larger geodynamic cycles of plate extension and subsequent convergence. For the Alps, geological reconstructions suggest a horizontally forced subduction initiation caused by the onset of convergence between the Adriatic and European plates. During Alpine orogeny, the Piemont-Liguria basin and the European passive magma-poor margin (including the Briançonnais domain) were subducted below Adria. The petrological rock record indicates burial and subsequent exhumation of both continental and oceanic crustal rocks that were exposed to (ultra)high-pressure metamorphic conditions during their Alpine burial-exhumation cycle. Moreover, estimates of exhumation velocities yield magnitudes in the range of several mm/yr to several cm/yr. However, published estimates of exhumation velocities, ages of peak metamorphic conditions and estimates for peak pressure and peak temperature vary partly significantly, even for the same tectonic unit. Consequently, many, partly significantly, contrasting conceptual models for subduction initiation (convergence versus buoyancy driven) or rock exhumation (channel-flow, diapirism, episodic regional extension, erosion etc.) have been proposed for the Alps. </p><p>Complementary to the data-driven approach, mathematical models of the lithosphere and upper mantle system are useful tools to investigate geodynamic processes. These mathematical models integrate observational and experimental data with the fundamental laws of physics (e.g. conservation of mass, momentum and energy) and are useful to test conceptual models of subduction initiation and rock exhumation. Here, we present numerical solutions of two-dimensional petrological-thermo-mechanical models. The initial model configuration consists of an isostatically and thermally equilibrated lithosphere, which includes mechanical heterogeneities in the form of elliptical regions with different effective viscosity. We model a continuous geodynamic cycle of subsequent extension, no far-field deformation and convergence. During extension, the continental crust is necked, separated and mantle is exhumed, forming a marine basin bounded by passive margins. During the subsequent stage with no far-field deformation, the thermal field of the lithosphere is re-equilibrated above a convecting mantle. During convergence, subduction is initiated at one passive margin and the mantle lithosphere below the marine basin as well as the other passive margin are subducted. During progressive subduction, parts of the subducted continental upper crust are sheared-off the subducting plate and are exhumed to the surface, ultimately forming an orogenic wedge. For the convergence, we test the impact of serpentinites at the top of the exhumed mantle on orogenic wedge formation. We compare the model results with observational and experimental constraints, discuss the involved processes and driving forces and propose a model for subduction initiation and (ultra)high-pressure rock exhumation for the Alps.</p>

The Alps 1: A working geodynamic model for burial and exhumation of (ultra)high-pressure rocks in Alpine-type orogens

2013 ◽  
Vol 377-378 ◽  
pp. 114-131 ◽  
Author(s):  
Jared P. Butler ◽  
Christopher Beaumont ◽  
Rebecca A. Jamieson
Keyword(s):  
High Pressure ◽  
Geodynamic Model ◽  
Ultra High Pressure ◽  
The Alps

scholarly journals Trans-lithospheric diapirism explains the presence of ultra-high pressure rocks in the European Variscides

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Petra Maierová ◽  
Karel Schulmann ◽  
Pavla Štípská ◽  
Taras Gerya ◽  
Ondrej Lexa
Keyword(s):  
High Pressure ◽  
Numerical Models ◽  
Classical Concept ◽  
Plate Interface ◽  
Ultra High Pressure ◽  
Common Process ◽  
Mountain Belts ◽  
Collisional Orogens ◽  
Rock Association ◽  
European Variscides

AbstractThe classical concept of collisional orogens suggests that mountain belts form as a crustal wedge between the downgoing and overriding plates. However, this orogenic style is not compatible with the presence of (ultra-)high pressure crustal and mantle rocks far from the plate interface in the Bohemian Massif of Central Europe. Here we use a comparison between geological observations and thermo-mechanical numerical models to explain their formation. We suggest that continental crust was first deeply subducted, then flowed laterally underneath the lithosphere and eventually rose in the form of large partially molten trans-lithospheric diapirs. We further show that trans-lithospheric diapirism produces a specific rock association of (ultra-)high pressure crustal and mantle rocks and ultra-potassic magmas that alternates with the less metamorphosed rocks of the upper plate. Similar rock associations have been described in other convergent zones, both modern and ancient. We speculate that trans-lithospheric diapirism could be a common process.

scholarly journals Advances in ultra‐high‐pressure and multi‐dimensional liquid chromatography instrumentation and workflows

2021 ◽  
Author(s):  
Jelle De Vos ◽  
Dwight Stoll ◽  
Stephan Buckenmaier ◽  
Sebastiaan Eeltink ◽  
James P. Grinias
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Ultra High Pressure
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