Stratigraphy, facies and high pressure -- medium temperature metamorphism of the Hallstatt limestones of the Pailwand (Northern Calcareous Alps, Austria)

2000 ◽  
Vol 150 (4) ◽  
pp. 641-671
Author(s):  
Hans-Jürgen Gawlick ◽  
Norbert Höpfer
Keyword(s):  
High Pressure ◽  
Northern Calcareous Alps ◽  
Medium Temperature ◽  
Northern Calcareous ◽  
Pressure Medium

High-pressure medium-temperature metamorphism of semi-pelitic rocks in the Scotia Metamorphic Complex, Powell Island, South Orkney Islands, Antarctica

2019 ◽  
Vol 91 ◽  
pp. 8-26
Author(s):  
Rodrigo Vinagre da Costa ◽  
Renato de Moraes ◽  
Rudolph Allard Johannes Trouw ◽  
Luiz Sérgio Amarante Simões ◽  
Julio Cezar Mendes
Keyword(s):  
High Pressure ◽  
Metamorphic Complex ◽  
Medium Temperature ◽  
Orkney Islands ◽  
South Orkney Islands ◽  
Pressure Medium ◽  
Pelitic Rocks

scholarly journals Correlation of metabasic rocks from metamorphic soles of the Dinaridic and the Western Vardar zone ophiolites (Serbia): Three contrasting pressure-temperature-time paths

2012 ◽  
pp. 61-85
Author(s):  
Danica Sreckovic-Batocanin ◽  
Nada Vaskovic ◽  
Vesna Matovic ◽  
Violeta Gajic
Keyword(s):  
High Pressure ◽  
Tectonic Setting ◽  
Granulite Facies ◽  
Oceanic Lithosphere ◽  
Medium Temperature ◽  
Vardar Zone ◽  
High Pressure High Temperature ◽  
Pressure Medium ◽  
Compositional Variations ◽  
Temperature Time

The field, petrological-mineralogical, geochemical and geochronological data of the metamorphic sole rocks recorded beneath the Fruska Gora, Povlen (Tejici), Stolovi and Banjska ophiolites in the Western Vardar Zone (WVZ) and beneath the Zlatibor, Bistrica, Sjenicki Ozren and Brezovica ophiolites in the Dinaridic ophiolite belt (DOB) in Serbia are compared. The focus has been made on metabasic rocks formed in contact with the oceanic crust members: cumulate gabbro and basalts of SSZ-type with E-MORB and OIB-signature and more evolved tholeiitic basalts of MOR-affinity. Amphibole, the major phase formed from the mafic sole components, depending on pressure-temperature conditions exhibits compositional variations. According to mineral assemblages, estimated P-T conditions and ages, the potential P-T paths are given: high pressure - low temperature blueschist facies assemblage (7-9 kbar and ~400?C and <300-350?C and 4-8 kbar), recorded only in the metamorphic sole at the Fruska Gora (WVZ); high pressure - high temperature amphibolite to granulite facies (8-10 kbar and >700-850?C), recorded in both domains, the WVZ (Banjska) and the DOB (Bistrica, Sjenicki Ozren, Brezovica) and medium pressure - medium temperature amphibolite facies assemblages (~3.5-7 kbar and >350-650?C) recognized in the WZV (Tejici, Devovici) and the DOB (Zlatibor). The peak metamorphic conditions point to depths of the oceanic lithosphere detachment and its initial cooling at 10-30 km, but the ages and tectonic setting of ophiolites remain poorly constrained. The summarized data may be used as an important key in geodynamic evolution of the Mesozoic Tethyan ophiolites.

scholarly journals Evidence for the Late Cretaceous Asteroussia event in the Gondwanan Ios basement terranes

2020 ◽  
Author(s):  
Sonia Yeung ◽  
Marnie Forster ◽  
Emmanuel Skourtsos ◽  
Gordon Lister
Keyword(s):  
High Pressure ◽  
Late Cretaceous ◽  
Metamorphic Core Complex ◽  
Metamorphic Event ◽  
Core Complex ◽  
Medium Temperature ◽  
Pressure Medium ◽  
Extreme Extension ◽  
The Individual ◽  
Metamorphic Core

Abstract. 40Ar/39Ar geochronology on garnet-mica schists and the underlying Gondwanan granitoid basement terrane on Ios demonstrates evidence of a Late Cretaceous high pressure, medium temperature (HP–MP) metamorphic event. This suggests that the Asteroussia crystalline nappe on Crete may extend northward and include Ios, in the Cyclades. If this is correct, the northern part of the Asteroussia nappe (on Ios) is overlain by the terrane stack defined by the individual slices of the Cycladic Eclogite-Blueschist Unit, whereas in the south (in Crete) the Asteroussia nappe is at the top of a nappe stack defined by the individual tectonic units of the external Hellenides. This geometry implies that the accretion of the Ios basement terrane involved a significant leap (250–300 km) southwards of the surface outcrop of the subduction megathrust. This accretion would have commenced at or about ~38 Ma, when the already exhumed terranes of the Cycladic Eclogite-Blueschist Unit had begun to thrust over the Ios basement. By ~35 Ma, we suggest the subduction jump had been accomplished, and renewed rollback began the extreme extension that led to the exhumation of the Ios metamorphic core complex.

scholarly journals Compressibility Studies of Zirconium Based Metal-Organic Frameworks

2014 ◽  
Vol 70 (a1) ◽  
pp. C157-C157
Author(s):  
Claire Hobday ◽  
Stephen Moggach ◽  
Carole Morrison ◽  
Tina Duren ◽  
Ross Forgan
Keyword(s):  
High Pressure ◽  
Mechanical Stability ◽  
Metal Organic Frameworks ◽  
External Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Crystallography ◽  
Pressure Medium ◽  
Metal Organic ◽  
University Of Oslo

Metal-organic frameworks (MOFs) are a well-studied class of porous materials with the potential to be used in many applications such as gas storage and catalysis.[1] UiO-67 (UiO = University of Oslo), a MOF built from zirconium oxide units connected with 4,4-biphenyldicarboxylate (BDC) linkers, forms a face centred cubic structure. Zirconium has a high affinity towards oxygen ligands making these bridges very strong, resulting in UiO-based MOFs having high chemical and thermal stability compared to other MOF structures. Moreover, UiO-67 has become popular in engineering studies due to its high mechanical stability.[2] Using high pressure x-ray crystallography we can exert MOFs to GPa pressures, experimentally exploring the mechanical stability of MOFs to external pressure. By immersing the crystal in a hydrostatic medium, pressure is applied evenly to the crystal. On surrounding a porous MOF with a hydrostatic medium composed of small molecules (e.g. methanol), the medium can penetrate the MOF, resulting in medium-dependant compression. On compressing MOF-5 (Zn4O(BDC)3) using diethylformamide as a penetrating medium, the framework was shown to have an increased resistance to compression, becoming amorphous several orders of magnitude higher in pressure than observed on grinding the sample.[3] Here we present a high-pressure x-ray diffraction study on the UiO-based MOF UiO-67, and several new synthesised derivatives built from same metal node but with altered organic linkers, allowing us to study in a systematic way, the mechanical stability of the MOF, and its pressure dependence on both the linker, and pressure medium.

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