La découverte à l'affleurement des premières roches granulitiques du Haut-Allier (Massif Central, France) nous incita à entreprendre la cartographie détaillée de cette région, en s'éloignant progressivement des premiers affleurements recensés. D'année en année, tous les termes pétrographiques actuellement reconnus dans les séries granulitiques mond...
Published in Mineralogical Magazine
Talc was identified as an equilibrium associate of omphacite, kyanite, zoisite, and garnet in some coesitebearing eclogites and as a retrograde phase in associated garnet peridotite from the Bixiling mafic-ultramafic complex in the Dabie ultrahigh-P metamorphic terrane, central China. Observed talc- and tremolite-bearing assemblages within the coex...
Published in Chinese Science Bulletin
Numerous eclogite-amphibolite blocks have been found along the Mayanling fault in the northern Dabie complex. Most of the eclogites are strongly retrograded and contain garnet, rutile and the amphibole-plagioclase symplectite. The occurrence of these eclogites may have something to do with the inverted movement of the Mayanling thrust fault.
Published in Chinese Science Bulletin
Isotopic geochemical characteristics of helium in garnet and omphacite of eclogite in the Dabie Mountains are discussed. Concentrations of3He and4He in garnet and omphacite are 3.9 × 10−14–24.0 × 10−14 and 0.48 × 10−7–9.42 × 10−7cm13.g−1, respectively. Values of3He/4He have a range of (1.19–4.63) × 10−7. Helium In the eclogite is derived from both ...
Published in Chinese Science Bulletin
The mineral inclusions in accessory minerals of the country gneisses have been studied in order to interpret relation between eclogites and their country gneissic rocks. Omphacite inclusions have been identified in titanite and zircon, which indicates that the present mineral assemblages of country gneisses are the last retrograded assemblages and ...
Published in Chinese Science Bulletin
Eclogite was first discovered at the northern margin of the Qaidam Basin in this study. It occurs as pods in the gneiss sequence of Middle to Upper Proterozoic age and is mainly composed of garnet, omphacite, phengite and rutile. The garnets contain 44%–62% of almandine, 15%–33% of grossular and 12%–30% of pyrope molecules, and the omphacites conta...
Published in Chinese Science Bulletin
The eclogite, discovered in Liuyuan, occurs as lenticular enclave within granitic gneiss. It has typical features of eclogite in petrology and mineralogy. The eclogite provides an important window to reconstruct the tectonic border of the Tarim block. The granitoids, located in Baihu area, yield U-Pb zircon ages of 1 660–2 000 Ma (Palaeoproterozoic...
Published in Chinese Journal of Geochemistry
Carbonate rocks are one of the major hosts to eclogite in the Mt. Dabie region. Eclogite bodies enclosed in the carbonate rocks occur mostly as knobs, ovoids and lenses measuring centimeters to tens of centimeters in size. The bodies have been intensely carbonatized and usually have transitional contacts with their carbonate hosts. The carbonate ro...
Published in Chinese Science Bulletin
Some eclogites and the related high-P metamorphic belt have been found for the first time from the Tongbai Mountains, Henan Province, where the eclogites and their probable retrogressive products —garnet amphibolites—occur as lenses in mica-schists. The fresh eclogites comprise garnet, omphacite, quartz, rutile, phengite, barroisite, etc. The compo...
Published in Chinese Science Bulletin
The eclogites of Altyn Tagh tectonic belt occur as lens within gneisses characterized by amphibolite-facies mineral parageneses. The well-preserved eclogite is selected for Sm-Nd and U-Pb isotopic dating. The Sm-Nd isotopic data yield a whole rock-garnet-omphacite isochron of (500 ± 10) Ma. The U-Pb isotopic measurements of zircons show that the fo...
