High-temperature contact metamorphism of calc-silicate xenoliths in the Kiglapait Intrusion, Labrador

2000 ◽  
Vol 85 (11-12) ◽  
pp. 1595-1605 ◽  
Author(s):  
Brent E. Owens
Keyword(s):  
High Temperature ◽  
Contact Metamorphism

Intracrystalline redistribution of Pb in zircon during high-temperature contact metamorphism

2005 ◽  
Vol 217 (1-2) ◽  
pp. 1-28 ◽  
Author(s):  
Christopher R.M. McFarlane ◽  
James N. Connelly ◽  
William D. Carlson
Keyword(s):  
High Temperature ◽  
Contact Metamorphism

Metamorphism and deformation of the Grand Forks complex: implications for the exhumation history of the Shuswap core complex, southern British Columbia

2012 ◽  
Vol 49 (11) ◽  
pp. 1329-1363 ◽  
Author(s):  
Joel F. Cubley ◽  
David R.M. Pattison
Keyword(s):  
British Columbia ◽  
High Temperature ◽  
Granulite Facies ◽  
Greenschist Facies ◽  
Contact Metamorphism ◽  
Low Grade ◽  
Core Complex ◽  
The West ◽  
Grand Forks ◽  
Exhumation History

The Grand Forks complex (GFC) is an elongate, north–south-trending metamorphic core complex in the Shuswap domain of southeastern British Columbia. It comprises predominantly upper-amphibolite- to granulite-facies paragneisses, schists, orthogneisses, amphibolites, and calc-silicates of the Paleoproterozoic to Paleozoic Grand Forks Group. The GFC is juxtaposed against low-grade rocks of the Quesnel terrane across two bounding Eocene normal faults: the Kettle River fault (KRF) on the east flank and the Granby fault (GF) on the west flank. Peak metamorphic Sil + Kfs ± Grt ± Crd (Sil, sillimanite; Kfs, potassium feldspar; Grt, garnet; Crd, cordierite) assemblages in paragneiss and Hbl ± Opx ± Cpx (Hbl, hornblende; Opx, orthopyroxene; Cpx, clinopyroxene) assemblages in amphibolite in the GFC formed at 750 ± 25 °C, 5.6 ± 0.5 kbar (1 kbar = 100 MPa; 20 ± 2 km depth). Stratigraphically overlying Sil + St-bearing pelitic schists (St, staurolite) within the complex record peak conditions of 600 ± 15 °C, 5.5 ± 0.25 kbar. Crd + Ilm + Spl (Crd, cordierite; Ilm, ilmenite; Spl, spinel) and Crd + Qtz (Qtz, quartz) coronal textures in paragneiss, and Cpx + Opx + Pl + Mt (Pl, plagioclase; Mt, magnetite) symplectites in amphibolite, formed at 735 ± 20 °C, 3.3 ± 0.5 kbar, indicating high-temperature, near-isothermal decompression of the GFC of ∼2.3 ± 0.7 kbar (∼8.2 ± 2.5 km) from peak conditions. Transitional greenschist–amphibolite metamorphic assemblages in the hanging wall of the KRF indicate conditions of ∼425 ± 25 °C and 2.2 ± 0.6 kbar (∼8 ± 2 km depth), with local contact metamorphism around Jurassic intrusions as high as 630–650 °C at ∼2.5 ± 0.5 kbar. The pressure contrast across the Kettle River fault prior to greenschist facies displacement was ∼0.8 ± 0.7 kbar, for a vertical offset of ∼2.9 ± 2.5 km. This is similar to estimates for the Granby fault on the west flank of the GFC. The GFC therefore experienced a two-stage exhumation history: early high-temperature decompression at upper-amphibolite- to granulite-facies conditions, followed by low-temperature exhumation at greenschist-facies conditions owing to movement on the Eocene Granby and Kettle River faults.

scholarly journals Mineralogy of a High-Temperature Skarn, in High CO2 Activity Conditions: The Occurrence from Măgureaua Vaţei (Metaliferi Massif, Apuseni Mountains, Romania)

Minerals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 677
Author(s):  
Ştefan Marincea ◽  
Delia-Georgeta Dumitraş ◽  
Cristina Sava ◽  
Frédéric Hatert ◽  
Fabrice Dal Bo
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Upper Cretaceous ◽  
Contact Metamorphism ◽  
High Co2 ◽  
Shallow Level ◽  
Apuseni Mountains ◽  
Hydrothermal Stage ◽  
Metamorphic Assemblage ◽  
Hydrothermal Event

A shallow-level monzodioritic to quartz-monzodioritic pluton of the Upper Cretaceous age caused contact metamorphism of Tithonic–Kimmeridgian reef limestones at Măgureaua Vaţei (Metaliferi Massif, Apuseni Mountains, Romania). The preserved peak metamorphic assemblage includes gehlenite (Ak 33.64–38.13), monticellite, wollastonite-2M, Ti-poor calcic garnet, and Ca-Tschermak diopside (with up to 11.15 mol.% Ca-Tschermak molecule). From the monzodioritic body to the calcitic marble, the periplutonic zoning can be described as: monzodiorite/agpaitic syenite-like inner endoskarn/wollastonite + perovskite + Ti-poor grossular + Al-rich diopside/wollastonite + Ti-poor grossular + diopside + vesuvianite/gehlenite + wollastonite + Ti poor grossular + Ti-rich grossular (outer endoskarn)/wollastonite + vesuvianite + garnet (inner exoskarn)/wollastonite + Ti-rich garnet + vesuvianite + diopside (outer exoskarn)/calcitic marble. Three generations of Ca garnets could be identified, as follows: (1) Ti-poor grossular (Grs 53.51–81.03 mol.%) in equilibrium with gehlenite; (2) Ti-rich grossular (Grs 51.13–53.47 mol.%, with up to 19.97 mol.% morimotoite in solid solution); and (3) titanian andradite (Grs 32.70–45.85 mol.%), with up to 29.15 mol.% morimotoite in solid solution. An early hydrothermal stage produced retrogression of the peak paragenesis toward vesuvianite, hydroxylellestadite (or Si-substituted apatite), clinochlore, “hibschite” (H4O4-substituted grossular). A late hydrothermal event induced the formation of lizardite, chrysotile, dickite, thaumasite, okenite and tobermorite. A weathering paragenesis includes allophane, C-S-H gels and probably portlandite, unpreserved because of its transformation in aragonite then calcite. Overprints of these late events on the primary zoning are quite limited.

scholarly journals Inverted metamorphic zonation in the hanging and foot walls of the Mahabharat Thrust, Kathmandu-Trishuli area, central Nepal

1970 ◽  
Vol 14 ◽  
pp. 51-58
Author(s):  
Sobit Prasad Thapaliya ◽  
Lalu Prasad Paudel
Keyword(s):  
High Temperature ◽  
Hanging Wall ◽  
Contact Metamorphism ◽  
Foot Wall ◽  
Central Nepal ◽  
Garnet Zone

Geological study was carried out along the Pasang Lahmu Highway from Kathmandu to Trishuli Bazaar covering both theLesser Himalayan autochthonous unit and the Kathmandu Nappe. The Lesser Himalayan rocks in the study area belong to theKunchha Formation, Benighat Slate and the Robang Formation of the Nawakot Complex. The Kathmandu Nappe (KathmanduComplex) comprises the Kalitar Formation, Gneiss Zone, Tistung Formation, Sopyang Formation and the Chandragiri Limestone.Petrographic study was carried out in the samples representing all the lithological units along the Pasang-Lahmu Highway.The study shows that the Kunchha Formation belongs to the biotite zone. The overlying units (Benighat Slate and RobangFormations) belong to the garnet zone. It is a clear evidence of inverted metamorphic zonation at the foot wall of the KathmanduNappe. The rocks of the Kathmandu Complex above the Mahabharat Thrust north of Kakani also show an inverse metamorphiczonation, i.e., the garnet zone is overlain by the sillimanite zone. However, in the southern part, the metamorphic zonation isnormal with biotite zone overlain by the chlorite zone. Although the inverted metamorphic zonation at the hanging wall of theMahabharat Thrust may be related to the high temperature contact metamorphism by pegmatite injection, the inverted metamorphismat the footwall needs an explanation.DOI: http://dx.doi.org/10.3126/bdg.v14i0.5439Bulletin of the Department of Geology, Vol. 14, 2011 pp. 51–58 

Influence of Thermo-Mechanical Processing on the Microstructure of Beryllia Dispersed Nickel Alloys

1973 ◽  
Vol 31 ◽  
pp. 184-185
Author(s):  
M.S. Grewal ◽  
S.A. Sastri ◽  
N.J. Grant
Keyword(s):  
High Temperature ◽  
Nickel Alloys ◽  
Thermomechanical Processing ◽  
Cold Work ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Mechanical Processing ◽  
Uniform Dispersion ◽  
Oxide Particles ◽  
Nickel Base

Currently there is a great interest in developing nickel base alloys with fine and uniform dispersion of stable oxide particles, for high temperature applications. It is well known that the high temperature strength and stability of an oxide dispersed alloy can be greatly improved by appropriate thermomechanical processing, but the mechanism of this strengthening effect is not well understood. This investigation was undertaken to study the dislocation substructures formed in beryllia dispersed nickel alloys as a function of cold work both with and without intermediate anneals. Two alloys, one Ni-lv/oBeo and other Ni-4.5Mo-30Co-2v/oBeo were investigated. The influence of the substructures produced by Thermo-Mechanical Processing (TMP) on the high temperature creep properties of these alloys was also evaluated.

Application of TEM to Deformation, Wear, and Fracture of Ceramics

1974 ◽  
Vol 32 ◽  
pp. 472-473
Author(s):  
B. J. Hockey
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Brittle Materials ◽  
High Temperature Strength ◽  
Wide Range ◽  
Corrosive Environments ◽  
Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

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