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    Petrology, phase equilibria and monazite geochronology of granulite-facies metapelites from deep drill cores in the Ordos Block of the North China Craton
    Lithos (2016)
    Xiao‐Fang HeM. SantoshKiara BockmannDavid E. KelseyMartin Hand
    Geochronology
    Sillimanite
    Citations (25)
    Extensional exhumation of a high-pressure granulite terrane in Payer Land, Greenland Caledonides: structural, petrologic, and geochronologic evidence from metapelites
    Canadian Journal of Earth Sciences (2002)
    Jane A. GilottiSynnøve Elvevold
    The Payer Land gneiss complex is unique among the mostly amphibolite-facies, mid-crustal gneiss complexes in the East Greenland Caledonides due to its well-preserved, regional high-pressure (HP) granulite-facies metamorphism. High-pressure – high-temperature (HP–HT) assemblages are recognized in mafic, ultramafic, granitic, and metasedimentary lithologies. Anatectic metapelites contain the assemblage garnet + kyanite + K-feldspar + antiperthite (exsolved ternary feldspar) + quartz ± biotite ± rutile and record approximately the same peak metamorphic conditions (pressure (P) = 1.4–1.5 GPa, temperature (T) = 800–850°C) as those of the neighboring mafic HP granulites. The HP granulite-facies metamorphism is Caledonian based on in situ U–Th–Pb electron microprobe dating of monazite from two samples of the aluminous paragneiss. The monazites are found along garnet–kyanite phase boundaries, as inclusions in garnet and kyanite, and within small leucocratic melt pods (K-feldspar + plagioclase + kyanite ± garnet) within the HP–HT paragneisses. Mylonitic equivalents of the metapelites contain a detrital monazite age signature that suggests the Payer Land paragneisses correlate with other Mesoproterozoic metasedimentary sequences in the area. The gneisses form a metamorphic core complex that is separated from the overlying low-grade sedimentary rocks of the Neoproterozoic Eleonore Bay Supergroup by an extensional detachment. This newly recognized Payer Land detachment is part of a system of prominent extensional faults located in the southern half of the Greenland Caledonides (i.e., south of 76°N). The HP granulites preserve the deepest level of crust exposed in this southern segment of the orogen and attest to significant crustal thickening.
    Sillimanite
    Citations (50)
    Petrological and geochemical evidence of the Paleoproterozoic and the Meso-Neoproterozoic sedimentary rocks of the Bastar craton, Indian Peninsula: Implications on paleoweathering and Proterozoic crustal evolution
    Journal of Asian Earth Sciences (2010)
    H. WaniM. E. A. Mondal
    Felsic
    Pelite
    Citations (39)
    Rock association and its evolution in the Bixiling and Shuanghe areas in the Dabie UHP metamorphic terrane, southwestern Anhui
    Regional Geology of China (2004)
    Zhou Hanwen
    Bixiling and Shuanghe are two typical outcrop areas in the Dabie ultrahigh-pressure (UHP) metamorphic terrane. Based on field outcrop observations and petrographic and petrochemical studies, the authors find that the rock association consists predominantly of eclogite, amphibolite, gneiss and foliated garnet-bearing granite. Eclogite has the characteristics of the crustal source and is considered to form by UHP metamorphism crustal rocks in the deep interior of the mantle; amphibolite is the product of retrogressive metamorphism of eclogites during exhumation of the plate; gneiss was produced by anatexis and progressive evolution of amphibolite in an ideal environment during exhumation; and foliated garnet-bearing granite is the result of partial melting of gneiss. In conclusion, there is a reworked in-situ relationship between eclogite and gneiss (and/or foliated garnet-bearing granite).
    Anatexis
    Outcrop
    Migmatite
    Citations (0)
    Mesoproterozoic (Grenville-age) granitoids and supracrustal rocks in Kaokoland, northwestern Namibia
    Precambrian Research (2017)
    Alfred KrönerYamirka Rojas‐Agramonte
    Felsic
    Diorite
    Citations (21)
    Ultrahigh-pressure metamorphic evidence for gneiss from the northern Dabie complex, central China: message from zircon.
    Acta Petrologica Sinica (2006)
    Yi Liu
    Micro-inclusions and the U-Pb age of zircons were investigated from the banded gneiss in the northern Dabie complex, central China Mineral inclusions in zircon from the gneiss,combined with cathodoluminescene images and isotopic dating, can be divided into three generations, i. e. primary magma assemblage of feldspar + biotite + quartz + apatite, ultrahigh-pressure ( UHP) metamorphic assemblage of diamond + garnet + rutile, and granulite-facies retrograde assemblage such as diopside. Diamond and garnet occurred as inclusion in diopside, which is representative retrograde mineral of granulite-facies in the northern Dabie complex. The zircons from the studied gneiss, analyzed by SHRIMP U-Pb, yielded peak metamorphic age of 218±3Ma and granulite-facies retrograde age of 199±10Ma. The evidences for UHP metamorphism were firstly discovered on the gneiss from the northern Dabie complex, indicating the banded gneiss of northern Dabie complex suffered Triassic UHP metamorphism as well as the enclosed eclogites.
    Citations (4)