The Isua greenstone belt (Fig. 1) contains the oldest known, relatively well preserved, metavolcanic and metasedimentary rocks on Earth. The rocks are all deformed and many were substantially altered by metasomatism, but both the deformation and metasomatism were heterogeneous. Transitional stages can be seen from relatively well preserved primary volcanic and sedimentary structures to schists ...

Charnockitic rocks form extensive orthogneiss plutons in many granulite terranes and are less commonly found in unmetamorphosed plutons, which have formed in various tectonic regimes. Geochemically, clearly igneous charnockites cover nearly the whole range of granite chemistry, from magnesian to ferroan and from calcic to alkalic. Pyroxenes from unmetamorphosed charnockitic rocks have compositi...

Micro-Fabric Analyzer (MFA) is a new GIS-based tool for the quantitative extrapolation of rock microstructural features that takes advantage both characteristics X-ray images and optical image features. Most previously developed edge mineral grain detectors are uniquely based on physical properties X-ray-, electron-, or optical-derived images; not permitting exploitation specific each type at s...

the aligoodarz granitoid occurs in sanandaj-sirjan zone (ssz), western iran. tonalite, granodiorite and granite are the main rock types cropping out in the area. comparison of aligoodarz granitoid with dehno and boroujerd granitoids reveals several similarities in their chemical characteristics. thus, the above mentioned granitoids can be assigned as a co-genetic magmatic suite, in which pluton...

The Bohai Bay Basin basement is mainly composed of Archean granitoid gneisses with minor supracrustal rocks and the largest basin in Eastern Block North China Craton. Due to a cover Mesozoic Cenozoic strata, little known about age crustal evolution this basement. In study we report new zircon SHRIMP LA-ICP-MS U-Pb Lu-Hf isotope data for drill core samples, including TTGs (granodiorite, tonalite...

Abstract Archean (4.0–2.5 Ga) tonalite–trondhjemite–granodiorite (TTG) terranes represent fragments of Earth’s first continents that formed via high-grade metamorphism and partial melting hydrated basaltic crust. While a range geodynamic regimes can explain the production TTG magmas, processes by which they separated from their source acquired distinctive geochemical signatures remain uncertain...

The appearance of the earliest felsic crust can be estimated by dating zircons and rocks tonalite-trondhjemite-granodiorite (TTG) composition. However, necessary geodynamic processes that form basis for metamorphism differentiation as well role emerging TTG on evolving crustal dynamics is still poorly understood. To investigate formation with composition, we conduct a detailed analysis series p...

Twenty-four composite samples of the fine-grained matrix glacial diamictites deposited from Mesoarchaean to Palaeozoic have been analysed for their silicon isotope composition and used establish, first time, long-term secular Si record compositional evolution upper continental crust (UCC). Diamictites with Archaean Palaeoproterozoic Nd model ages show greater heterogeneity than those younger (i...