Topic
Granulite
About: Granulite is a research topic. Over the lifetime, 6763 publications have been published within this topic receiving 268925 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this paper, the authors present abundances and carbon isotope compositions of CO2 in fluid inclusions in quartz and garnet from gneiss-granulite pairs from the incipient char-nockite quarries of southern India, determined by a stepped combustion/thermal decrepitation carbon extraction technique.
Abstract: Models for the formation of crustal granulites, which include the metamorphism of anhydrous lithologies1,2, the extraction of hygroscopic granite melts3,4 and fluxing by CO25–7 constrain the thermal and geochemical evolution of the lower crust and its interaction with mantle-derived volatiles. Here we present abundances and carbon isotope compositions of CO2 in fluid inclusions in quartz and garnet from gneiss–granulite pairs from the incipient char-nockite quarries of southern India, determined by a stepped combustion/thermal decrepitation carbon–extraction technique, which quantifies problematic sample contamination and allows precise lithological control. The results show that the CO2 in incipient charnockite is more abundant and isotopically heavier than the CO2 in associated gneiss, providing evidence for the influx of CO2-rich fluids during their formation. The inferred carbon isotope compositions of these fluids are consistent with a mantle source, and at Ponmudi, the isotopic composition of coexisting graphite and CO2 implies fluid/rock volume ratios in excess of 0.15.
83 citations
TL;DR: Titanium-in-zircon thermometry has been applied to evaluate the temperatures of metamorphism for two ultrahigh-temperature (UHT) granulite localities, the Neoproterozoic Anapolis-Itaucu Complex in central Brazil, and lower crustal xenoliths from the Neo-archean Kaapvaal craton in South Africa as discussed by the authors.
Abstract: Titanium-in-zircon thermometry has been applied to evaluate the temperatures of metamorphism for two ultrahigh-temperature (UHT) granulite localities, the Neoproterozoic Anapolis-Itaucu Complex in central Brazil, and lower crustal xenoliths from the Neo-archean Kaapvaal craton in South Africa. UHT metamorphism in the Anapolis-Itaucu Complex occurred ca. 640 Ma. Ti-in-zircon thermometry on metamorphic zircon yields temperatures of 965–811 °C; a population of late zircon that formed from ilmenite and rutile breakdown records temperatures of ∼780 °C. Maximum temperatures are less than those inferred from quantitative phase equilibria modeling. Based on textural setting (inclusions in peak phases and as matrix grains), these zircons likely record growth during the pro-grade and/or postpeak evolution. In contrast, the Kaapvaal xenoliths record two phases of zircon growth: during UHT metamorphism at 2720–2715 Ma, followed by growth during isobaric cooling in kyanite-bearing leucosomes ca. 2690 Ma. Temperatures recorded by the two phases of growth are 1024–878 °C and 936–839 °C, respectively, suggesting that zircon growth occurred during UHT conditions and continued throughout the postpeak evolution over a 200 °C interval. These examples demonstrate that the Ti-in-zircon thermometer is a powerful new tool with the potential to determine crystallization temperatures of zircon during granulite facies metamorphism, throughout the prograde to postpeak evolution of such terranes.
83 citations
TL;DR: Pb zircon data from five igneous suites confirm previous studies that demonstrated widespread Pan-African magmatism in the Granulite Terrain of southern India as mentioned in this paper.
83 citations
TL;DR: A recent seismic, gravity and magnetic traverse across the western margin of the Yilgarn Craton, undertaken approximately 110 km north of Perth, together with new Rb-Sr and USr geochronological data from the southwestern portion of the craton, has led to a re-evaluation of the geological relationships and to the development of a terrane accretion model for the region as discussed by the authors.
83 citations
TL;DR: In this paper, high-pressure granulites were found as blocks within the Paleozoic sedimentary rocks of the North Lhasa terrane, which is the northern boundary of the Indian continent.
82 citations