Weakening associated with the diaspore–corundum dehydration reaction in metabauxites: an example from Naxos (Greece)

Urai, János L.; Feenstra, Anne

doi:10.1016/s0191-8141(00)00165-6

Cited by 26 publications

(23 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The dominant marble microstructure is characteristic of dynamic recrystallization at high temperature ( Fig. 8c): amoeboid grains with lobate grain boundaries and orientation families indicating extensive grain boundary migration (Urai and Feenstra, 2001). In triple junctions, angles between grain boundaries are typically ∼ 120 • .…”

Section: Marblementioning

confidence: 99%

“…The present-day metamorphic facies distribution is the result of at least three distinct metamorphic phases associated with Alpine deformation (Urai et al, 1990). The first metamorphic event at high-pressure, low-temperature conditions is associated with top-to-south shearing in the Hellenic subduction zone (D1), and formation of the Hellenides at approximately 50 Ma (Andriessen et al, 1979;Dürr et al, 1978;Urai et al, . Geological map of Naxos, modified after Jansen (1993), Vanderhage (2004) and Kruckenberg et al (2011).…”

Section: Geological Settingmentioning

confidence: 99%

“…Situated in the footwall of the North Cycladic detachment system and exposing a rich variety in lithologies and metamorphic facies, Naxos has been the subject of many studies to understand the tectonic history of the Aegean domain and the evolution of rheology under changing metamorphic grade (Buick, 1991;Gautier et al, 1993;Jansen, 1973;Jansen and Schuiling, 1976;Jolivet et al, 1994Jolivet et al, , 2004Keay et al, 2001;Urai et al, 1990;Urai and Feenstra, 2001;Krabbendam et al, 2003;Schenk et al, 2005).…”

Section: Geological Settingmentioning

confidence: 99%

See 2 more Smart Citations

Multiphase boudinage: a case study of amphibolites in marble in the Naxos migmatite core

2018

Self Cite

View full text Add to dashboard Cite

Abstract. In multiply deformed terrains multiphase boudinage is common, but identification and analysis of these is difficult. Here we present an analysis of multiphase boudinage and fold structures in deformed amphibolite layers in marble from the migmatitic centre of the Naxos metamorphic core complex. Overprinting between multiple boudinage generations is shown in exceptional 3-D outcrop. We identify five generations of boudinage, reflecting the transition from high-strain high-temperature ductile deformation to medium-to low-strain brittle boudins formed during cooling and exhumation. All boudin generations indicate E-W horizontal shortening and variable direction of bedding parallel extension, evolving from subvertical extension in the earliest boudins to subhorizontal N-S extension during exhumation. Two phases of E-W shortening can be inferred, the first associated with lower crustal synmigmatic convergent flow and the second associated with exhumation and N-S extension, possibly related to movement of the North Anatolian Fault.

show abstract

Section: Marblementioning

confidence: 99%

Section: Geological Settingmentioning

confidence: 99%

Section: Geological Settingmentioning

confidence: 99%

See 1 more Smart Citation

Multiphase boudinage: a case study of amphibolites in marble in the Naxos migmatite core

2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…In a natural example of a metamorphic dehydration reaction leading to transient strain softening, Urai & Feenstra (2001) found strongly deformed metabauxite lenses surrounded by marbles. The metabauxite deformation is explained by the dehydration from diasporite, which is also present in the area.…”

Section: Reaction Softeningmentioning

confidence: 99%

High-strain zones: laboratory perspectives on strain softening during ductile deformation

Burlini

Bruhn

2005

View full text Add to dashboard Cite

Deformation in the Earth's outer shell is mostly localized into narrow high-strain zones. Because they can have displacements up to several hundreds or thousands of kilometres, they can affect the entire lithosphere. The properties of high-strain zones control the kinematics and dynamics of our planet, and are therefore of key importance for an understanding of plate tectonics, stress accumulation and release (e.g. earthquakes), mountain building, etc.One of the requirements of shear zone formation in ductile rocks is localized strain softening (Hobbs et al. 1990). In this paper we review the strain softening mechanisms that were identified and proposed 25 years ago and analyse their relevance in light of recent experimental results conducted to large strains. For this purpose, some of the newer developments in experimental deformation techniques that permit high strain in torsion are summarized and recent results are reviewed. Using these results we discuss mechanisms, processes and conditions that lead to localization.Since the first deployment of GPS (Global positioning system) to monitor plate motion in the al. 2003). In contrast, the local strain rate at plate boundaries is several orders of magnitude higher and is restricted to narrow zones, even within more diffuse plate boundary zones such as central Asia. Since displacements along these high strain rate zones are of the order of hundreds of kilometres or more, they must affect the entire lithosphere. Paterson (2001) pointed out that to model the theology of the crust, one should consider it to be divided into blocks separated by faults (upper crust, where deformation is timeindependent) and shear zones (lower crust or even mantle, where the deformation is timedependent). The bulk rheology depends predominantly upon the behaviour of these shear zones.In trying to summarize and define the status quo of our knowledge about the formation and mechanical properties of shear zones it is helpful to take a look at a prescient summary published a quarter of a century ago by White et al. (1980). This and other publications we refer to were the result of a conference on shear zones in rocks held in Barcelona, Spain in 1979. We will follow the arguments of White et al. (1980) and include other publications which attempted to define the status quo at the time, for example the Penrose conference report on mylonites by Tullis et al. (1982).Although the general topic is broad, we will focus on one area, the formation of ductile shear zones due to localized relative strain softening. The questions posed at that time are discussed in the light of new results. Other important issues related to shear zones include reactivation, brittle faulting, and the role of high-strain zones as conduits for fluids, to name but a few, but these will only be addressed in so far as they affect the question of deformation mechanisms in ductile high-strain zones.

show abstract

“…It is located underneath the mountains of Naxos in lenticular formation. According to the most dominant theory, emery developed through the process of metamorphism of bauxites (Urai and Feenstra, 2001;Feenstra and Wunder, 2002). This metamorphism is calculated to have taken place during the Alpine deformation (75.000.000-25.000.000 years ago) under special conditions of pressure and temperature.…”

Section: Introductionmentioning

confidence: 99%

Following the Traces of Naxian Emery – An Implementation of Environmental Education in Geodidactics

Kritikou¹,

Malegiannaki²

2017

geosociety

View full text Add to dashboard Cite

show abstract

Weakening associated with the diaspore–corundum dehydration reaction in metabauxites: an example from Naxos (Greece)

Cited by 26 publications

References 36 publications

Multiphase boudinage: a case study of amphibolites in marble in the Naxos migmatite core

Multiphase boudinage: a case study of amphibolites in marble in the Naxos migmatite core

High-strain zones: laboratory perspectives on strain softening during ductile deformation

Following the Traces of Naxian Emery – An Implementation of Environmental Education in Geodidactics

Contact Info

Product

Resources

About