Zircon U–Pb and trace element data from rocks of the Huai’an Complex: New insights into the late Paleoproterozoic collision between the Eastern and Western Blocks of the North China Craton

U-Pb dating of zircon was undertaken with the Beijing SHRIMP II (sensitive high resolution ion microprobe) on anamphibolite facies granodiorite and an almandine-albite granulite from the Santa Maria Chico Granulitic Complex, southern Brazilian Shield. This work was also done to unravel protolith ages which are often hidden in the array of partly reset data. The obtained metamorphic ages of the granodiorite gneiss and the granulite are 2035 ± 9 Ma and 2006 ± 3 Ma, respectively. These data are within the range of metamorphic ages determined in previous studies (2022 ± 18 Ma and 2031 ± 40 Ma). However, protolith ages for the granodiorite (2366 ± 8 Ma) and the granulite (2489 ± 6 Ma) were obtained which are outside the previously recognized range (> 2510-2555 Ma). The magmatic protolith age of the granodiorite refers to a previously little known magmatic event in the shield. Further investigations may demonstrate that amphibolite facies zircon crystals are useful as a window into geological events in associated granulites, because zircon ages are blurred in the studied granulites.

Protolith

Almandine

10.1590/s0001-37652008000300014

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Citations (43)

Rb-Sr isotopic studies of a polymetamorphic granulite terrane, Strangways Range, central Australia

Lithos (1976)

Brijesh Iyer Peter John Woodford Allan F. Wilson

Felsic

Isochron dating

Isotopes of strontium

10.1016/0024-4937(76)90039-6

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Citations (44)

LA-ICP-MS U-Pb Zircon Dating for Felsic Granulite, Huangtuling Area, North Dabieshan: Constraints on Timing of Its Protolith and Granulite-Facies Metamorphism, and Thermal Events in Its Provenance

Journal of Earth Science (2017)

Nengsong Chen Rong Liu Min Sun Huimin Li Lei He

Protolith

Felsic

Source

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Petrology and geochemistry of ultrahigh‐temperature granulites from the South Altay orogenic belt, northwestern China: Implications for metamorphic evolution and protolith composition

Island Arc (2015)

Xiaoqiang Yang Zilong Li Huihui Wang Hanlin Chen Yinqi Li

Abstract Ultrahigh‐temperature ( UHT ) granulites in the S outh A ltay orogenic belt of N orthwestern C hina provide important clues for the lower crustal components and tectonic evolution of the C entral A sian O rogenic B elt during the P aleozoic. In this paper, we studied whole‐rock geochemistry and mineral characteristics to understand the protolith and metamorphic evolution of the A ltay UHT granulite. The A ltay granulite shows negative discriminant function values ( DF ) of −9.27 to −3.95, indicating a sedimentary origin, probably an argillaceous rock. The peak metamorphic temperature–pressure conditions of 920–1010 °C and > 9 kbar were estimated from the geothermobarometry, together with the stability of spinel (low ZnO ) + quartz and orthopyroxene ( Al 2 O 3 up to 9.2 wt.%) + sillimanite + quartz in the Altay UHT rock, indicate a UHT metamorphic condition has been achieved. Two stages of retrograde conditions are recognized in these rocks; the first is an isothermal decompression to approx. 750 °C at 5.2–5.8 kbar at the early stage, and the second is the cooling down to 520–550 °C at 4.8–5.2 kbar. Combined with previous study, the formation of the A ltay UHT pelitic granulite with a clockwise retrograde P – T path is inferred to be related with collisional and accretional orogenic process between the S iberian and K azakhstan– J unggar plates.

Protolith

Geothermobarometry

10.1111/iar.12102

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Citations (11)

Quantitative P–T–X constraints on orthopyroxene‐bearing high‐pressure granulites in felsic–metapelitic rocks: evidence from the Huangtuling granulite, Dabieshan Orogen

Journal of Metamorphic Geology (2007)

Yan Chen K. Ye J‐B. LIU Min Sun

Abstract High‐pressure granulites are generally characterized by the absence of orthopyroxene. However, orthopyroxene is reported in a few high‐pressure, felsic–metapelitic granulites, such as the Huangtuling felsic high‐pressure granulite in the North Dabie metamorphic core complex in east‐central China, which rarely preserves the high‐pressure granulite facies assemblage of garnet + orthopyroxene + biotite + plagioclase + K‐feldspar + quartz. To investigate the effects of bulk‐rock composition on the stability of orthopyroxene‐bearing, high‐pressure granulite facies assemblages in the NCKFMASHTO (Na 2 O–CaO–K 2 O–FeO–MgO–Al 2 O 3 –SiO 2 –H 2 O–TiO 2 –Fe 2 O 3 ) system, a series of P – T – X pseudosections based on the melt‐reintegrated composition of the Huangtuling felsic high‐pressure granulite were constructed. Calculations demonstrate that the orthopyroxene‐bearing, high‐pressure granulite facies assemblages are restricted to low X Al [Al 2 O 3 /(Na 2 O + CaO + K 2 O + FeO + MgO + Al 2 O 3 ) < 0.35, mole proportion] or high X Mg [MgO/(MgO + FeO) > 0.85] felsic–metapelitic rock types. This study also reveals that the X Al values in the residual felsic–metapelitic, high‐pressure granulites could be significantly reduced by a high proportion of melt loss. We suggest that orthopyroxene‐bearing, high‐pressure granulites occur in residual overthickened crustal basement under continental subduction–collision zones and arc–continent collision belts.

Felsic

10.1111/j.1525-1314.2007.00742.x

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Citations (23)

A petrophysical study of the composition of Taiwan's middle and lower crust

Tectonophysics (2023)

Dennis Brown Giovanni Camanni Hao Kuo‐Chen Joaquina Álvarez-Marrón

A first-order approximation of the lithological make-up of an orogen's middle and lower crust can provide insights into its structure, as well as the tectono-metamorphic and geodynamic processes taking place there. In this study, we investigate the possible lithological and chemical composition of Taiwan's middle and lower crust by matching in situ physical properties measured by the TAIGER tomography data with isotropic wavespeeds, density, and major element composition for a variety of upper amphibolite and granulite facies rocks modelled at ambient pressure and temperature using the AbersHacker Macro. The modelling suggests that Taiwan's middle crust is possibly comprised of some combination of biotite-poor metapelite, garnet-poor felsic granulite, mafic granulite, amphibolite, and marble. The lower crust is likely comprised of mafic granulite, garnet-rich felsic granulite, biotite-free metapelite, and eclogite. Furthermore, the modelling shows that the modal abundance of garnet and/or sillimanite has a significant effect on physical properties, elevating seismic wavespeeds and density of felsic rocks to those of mafic rocks. The modelled wt% major oxide composition suggests that Taiwan's middle and lower crust have a more mafic chemical composition than that of global compilations of the continental crust. Nevertheless, this reflects the choices made when assigning rock types for the lithological mix used to calculate the wt% oxides, since increasing the percentage of garnet-rich metapelite and felsic granulite would result in a more felsic bulk composition.

Felsic

10.1016/j.tecto.2023.230160

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