The occurrence of högbomite and taaffeite in a spinel-phlogopite schist from the Mount Painter Province of South Australia

SummaryA spinel-phlogopite schist from the Mount Painter Province of South Australia forms part of a highly magnesium- and aluminium-rich unit and contains the minerals högbomite and taaffeite. Taaffeite nucleated in spinel during upper amphibolite facies metamorphism. During a subsequent upper amphibolite facies metamorphic event both spinel and taaffeite were partially replaced by högbomite. Chemical analyses of högbomite, taaffeite, and spinel are presented.

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Zircon U–Pb Dating and Lu-Hf Isotope of the Retrograded Eclogite from Chicheng, Northern Hebei Province, China

Shock and Vibration ◽

10.1155/2021/1445653 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Xu Kong ◽

Xueyuan Qi ◽

Wentian Mi ◽

Xiaoxin Dong

Keyword(s):

Regional Metamorphism ◽

Granulite Facies ◽

Amphibolite Facies ◽

Metamorphic Event ◽

Isotopic Data ◽

Metamorphic Condition ◽

Eu Anomaly ◽

Facies Metamorphism ◽

Eclogite Facies ◽

Plagioclase Gneiss

We report zircon U–Pb ages and Lu-Hf isotopic data from two sample of the retrograded eclogite in the Chicheng area. Two groups of the metamorphic zircons from the Chicheng retrograded eclogite were identified: group one shows characteristics of depletion in LREE and flat in HREE curves and exhibit no significant Eu anomaly, and this may imply that they may form under eclogite facies metamorphic condition; group two is rich in HREE and shows slight negative Eu anomaly indicated that they may form under amphibolite facies metamorphic condition. Zircon Lu-Hf isotopic of εHf from the Chicheng eclogite has larger span range from 6.0 to 18.0, which suggests that the magma of the eclogite protolith may be mixed with partial crustal components. The peak eclogite facies metamorphism of Chicheng eclogite may occur at 348.5–344.2 Ma and its retrograde metamorphism of amphibolite fancies may occur at ca. 325.0 Ma. The Hongqiyingzi Complex may experience multistage metamorphic events mainly including Late Archean (2494–2448 Ma), Late Paleoproterozoic (1900–1734 Ma, peak age = 1824.6 Ma), and Phanerozoic (495–234 Ma, peak age = 323.7 Ma). Thus, the metamorphic event (348.5–325 Ma) of the Chicheng eclogite is in accordance with the Phanerozoic metamorphic event of the Hongqiyingzi Complex. The eclogite facies metamorphic age of the eclogite is in accordance with the metamorphism (granulite facies or amphibolite facies) of its surrounding rocks, which implied that the tectonic subduction and exhumation of the retrograded eclogite may cause the regional metamorphism of garnet biotite plagioclase gneiss.

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Mid amphibolite facies metamorphism of harzburgites in the Neoproterozoic Cerro Mantiqueiras Ophiolite, southernmost Brazil

Anais da Academia Brasileira de Ciências ◽

10.1590/s0001-37652003000100012 ◽

2003 ◽

Vol 75 (1) ◽

pp. 109-128 ◽

Cited By ~ 14

Author(s):

LÉO A. HARTMANN ◽

FARID CHEMALE-JÚNIOR

Keyword(s):

Mineral Assemblage ◽

Shear Zones ◽

Amphibolite Facies ◽

Ductile Deformation ◽

Metamorphic Event ◽

Mineral Equilibria ◽

Facies Metamorphism ◽

Geological Evolution ◽

Mineral Compositions

Valuable information is retrieved from the integrated investigation of the field relationships, microstructure and mineral compositions of harzburgites from the Neoproterozoic Cerro Mantiqueiras Ophiolite. This important tectonic marker of the geological evolution of southernmost Brazilian Shield was thoroughly serpentinized during progressive metamorphism, because the oldest mineral assemblage is: olivine + orthopyroxene + tremolite + chlorite + chromite. This M1 was stabilized in mid amphibolite facies - 550-600ºC as calculated from mineral equilibria. No microstructural (e.g. ductile deformation of olivine or chromite) or compositional (e.g. mantle spinel) remnant of mantle history was identified. A metamorphic event M2 occurred in the low amphibolite facies along 100 m-wide shear zones, followed by intense serpentinization (M3) and narrow 1-3 m-wide shear zones (M4) containing asbestos.

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The effects of amphibolite facies metamorphism on the trace element composition of pyrite and pyrrhotite in the Cambrian Nairne Pyrite Member, Kanmantoo Group, South Australia

Ore Geology Reviews ◽

10.1016/j.oregeorev.2019.103128 ◽

2019 ◽

Vol 114 ◽

pp. 103128

Author(s):

C. Dakota Conn ◽

Paul G. Spry ◽

Dan Layton-Matthews ◽

Alexandre Voinot ◽

Alan Koenig

Keyword(s):

Trace Element ◽

South Australia ◽

Trace Element Composition ◽

Element Composition ◽

Amphibolite Facies ◽

Facies Metamorphism

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DIVING DEEPER INTO THE PICURIS OROGEN: UPPER AMPHIBOLITE FACIES METAMORPHISM AND BRITTLE DEFORMATION ALONG THE PLOMO SHEAR ZONE

10.1130/abs/2020am-354334 ◽

2020 ◽

Author(s):

Adrian E. Castro ◽

◽

Chloe Bonamici ◽

Christopher G. Daniel ◽

Danielle Shannon Sulthaus

Keyword(s):

Shear Zone ◽

Amphibolite Facies ◽

Brittle Deformation ◽

Facies Metamorphism

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REGIONAL LOW-PRESSURE AMPHIBOLITE-FACIES METAMORPHISM AT THE PIPE II MINE, THOMPSON NICKEL BELT, MANITOBA, AND COMPARISON OF METAMORPHIC ISOGRADS IN METAPELITES AND META-IRON FORMATIONS

The Canadian Mineralogist ◽

10.3749/canmin.49.3.721 ◽

2011 ◽

Vol 49 (3) ◽

pp. 721-747 ◽

Cited By ~ 5

Author(s):

C. G. Coueslan ◽

D. R. M. Pattison ◽

D. K. Tinkham

Keyword(s):

Low Pressure ◽

Amphibolite Facies ◽

Facies Metamorphism ◽

Iron Formations

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Structural and geochronological constraints on the evolution of the Juréia Massif, Registro Domain, State of São Paulo, Brazil

Anais da Academia Brasileira de Ciências ◽

10.1590/s0001-37652007000300008 ◽

2007 ◽

Vol 79 (3) ◽

pp. 441-455 ◽

Cited By ~ 7

Author(s):

Cláudia R. Passarelli ◽

Miguel A.S. Basei ◽

Hélcio J. Prazeres-Filho ◽

Oswaldo Siga-Jr. ◽

Gergely A.J. Szabó ◽

...

Keyword(s):

Shear Zone ◽

Sao Paulo ◽

Amphibolite Facies ◽

Metamorphic Event ◽

São Paulo ◽

Paulo State ◽

The North ◽

Domain State ◽

Geochronological Constraints ◽

Shear System

The Juréia Massif, southeastern São Paulo State (Brazil), is part of the Registro Domain, limited to the north by the Cubatão-Itariri Shear System and to the south by the Serrinha Shear Zone. Mostly composed of migmatitic granitegneiss rocks, represents a Paleoproterozoic terrane (1.9-2.2 Ga) strongly deformed during the Neoproterozoic (750-580 Ma). The present tectonic scenario was established at the end of the Neoproterozoic, as a result of collages associated with the formation of Western Gondwana. The Ponta da Juréia, our study area within the Juréia Massif, is constituted by paragneisses (garnet-muscovite-biotite gneisses). The monazite U-Pb age of 750 Ma is related to a main regional metamorphic event that reached the high amphibolite facies, recorded in rocks from the Itatins Complex and Cachoeira Sequence as well, which also belongs to the Registro Domain. The paragneissic rocks of this study are affected by the E-W-trending Serrinha Shear Zone, registering a predominantly dextral movement. Biotite K-Ar ages of 482 ± 12 Ma may represent later movements and reflect the younger ages of reactivation of the major lineaments and juxtaposition of the tectonic blocks involved.

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Metamorphic evolution and U-Pb zircon SHRIMP geochronology of the Belizário ultramafic amphibolite, Encantadas Complex, southernmost Brazil

Anais da Academia Brasileira de Ciências ◽

10.1590/s0001-37652003000300010 ◽

2003 ◽

Vol 75 (3) ◽

pp. 393-403 ◽

Cited By ~ 20

Author(s):

Léo A. Hartmann ◽

João O.S. Santos ◽

Jayme A.D. Leite ◽

Carla C. Porcher ◽

Neal J. Mcnaughton

Keyword(s):

Ultramafic Rock ◽

Greenschist Facies ◽

Amphibolite Facies ◽

Rio De La Plata ◽

Metamorphic Evolution ◽

Río De La Plata ◽

La Plata ◽

Shrimp Geochronology ◽

Facies Metamorphism ◽

Magnesian Basalt

The integrated investigation of metamorphism and zircon U-Pb SHRIMP geochronology of the Belizário ultramafic amphibolite from southernmost Brazil leads to a better understanding of the processes involved in the generation of the Encantadas Complex. Magmatic evidence of the magnesian basalt or pyroxenite protolith is only preserved in cores of zircon crystals, which are dated at 2257 ± 12 Ma. Amphibolite facies metamorphism M1 formed voluminous hornblende in the investigated rock possibly at 1989 ± 21 Ma. This ultramafic rock was re-metamorphosed at 702±21 Ma during a greenschist facies eventM2; the assemblage actinolite + oligoclase + microcline + epidote + titanite + monazite formed by alteration of hornblende. The metamorphic events are probably related to the Encantadas Orogeny (2257±12 Ma) and Camboriú Orogeny (~ 1989 Ma) of the Trans-Amazonian Cycle, followed by an orogenic event (702±21 Ma) of the Brasiliano Cycle. The intervening cratonic period (2000-700 Ma) corresponds to the existence of the Supercontinent Atlantica, known regionally as the Rio de la Plata Craton.

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Mapping in the Fiskefjord area, southern West Greenland

Rapport Grønlands Geologiske Undersøgelse ◽

10.34194/rapggu.v110.7797 ◽

1982 ◽

Vol 110 ◽

pp. 55-57

Author(s):

A.A Garde ◽

V.R McGregor

Keyword(s):

Granulite Facies ◽

Amphibolite Facies ◽

Isotopic Age ◽

Supracrustal Rock ◽

Granulite Facies Metamorphism ◽

West Greenland ◽

Facies Metamorphism ◽

Geological Work ◽

Age Determinations

Previous geological work on the 1:100000 map sheet 64 V.l N (fig. 15) includes published maps of smaller areas by Berthelsen (1960, 1962) and Lauerma (1964), mapping by Kryolitselskabet Øresund A/S (Bridgwater et al., 1976) and mapping by GGU geologists for the 1:500000 map sheet Frederikshåb Isblink - Søndre Strømfjord (Allaart et al., 1977, 1978). The Amltsoq and Niik gneisses and Malene supracrustal rock units south and east of Godthåbsfjord have not so far been correlated with rocks in the Fiskefjord area. Godthåbsfjord separates the granulite facies gneisses in Nordlandet from amphibolite facies Nûk gneisses on Sadelø and Bjørneøen; the granulite facies metamorphism occurred at about 2850 m.y. (Black et al., 1973), while no published isotopic age determinations from the Fiskefjord area itself are available.

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