Abstract. Epidote – here defined as minerals belonging to the epidote–clinozoisite solid solution is a low-? (?=238U/204Pb) mineral occurring in variety of geological environments and participating many metamorphic reactions that stable throughout wide range pressure–temperature conditions. Despite containing fair amounts U, its use U?Pb geochronometer has been hindered by commonly high content...

Geochronology of Th-rich minerals is advantageous as it allows use three isotopic systems (i.e., 206Pb/238U, 207Pb/235U, and 208Pb/232Th) for accurate data assessment. The 208Pb/232Th system especially in cases where the dated mineral includes an initial Pb component, least sensitive to effects amongst systems. This benefit demonstrated with monazite from a white mica schist Tsäkkok Lens, Scand...

Abstract The Rocca Canavese Thrust Sheets Unit (RCTU) is a subduction-related mélange that represents the eastern-most complex of Sesia–Lanzo Zone (SLZ), bounded by Periadriatic (Canavese) Lineament separates Alpine subduction from Southalpine domain. RCTU limited to south Lanzo Massif (LM) and east Eclogitic Micaschists Complex (EMC). Particularly tectonic contact area RCTU, adjacent neighbour...

Pervasive alteration of basaltic oceanic crust by heated seawater at greenschist facies conditions produces two contrasting hydrothermal rocks. “Spilites”, consisting chlorite + albite quartz ± actinolite epidote, occur typically with regional extents. Locally spilites are metasomatically transformed to “epidosites” epidote titanite hematite or magnetite. Both types have been proposed as marker...

Abstract Many workers accept a metamorphic model for orogenic gold ore formation, where gold-bearing aqueous-carbonic fluid is an inherent product of devolatilization across the greenschist-amphibolite boundary with majority deposits formed within seismogenic zone at depths 6–12 km. Fertile oceanic rocks that source and metal may be heated through varied tectonic scenarios affecting deforming u...

The north-dipping Hout River Shear Zone (HRSZ), which marks the boundary between high-grade Limpopo Complex in its hanging wall and low-grade granite-greenstone terrane of Kaapvaal Craton South Africa footwall, is a deep-crustal shear zone that controlled emplacement hot granulites over against granite-greenstones during exhumation at ~2.72–2.62 Ga. This major migration large volumes hydrous fl...

Geochemical and isotopic fluid signatures from a 2.9 – 3.2 km deep, 45 55 ℃ temperature, hypersaline brine Moab Khotsong gold uranium mine in the Witwatersrand Basin of South Africa were combined with radiolytic water-rock exchange models to delineate evolution over geologic time, explore conditions for habitability. The brines (Ca-Na-Cl) 215 246 g/L TDS, Cl - concentrations up 4 mol/L suggesti...

The phosphate mineral monazite (LREE,Y,Th,Ca,Si)PO 4 occurs as an accessory phase in peraluminous granites and Ca-poor meta-psammopelites. Due to negligible common Pb very low diffusion rates at high temperatures, has received increasing attention geochronology. As the grain sizes are mostly below 100 ?m upper greenschist amphibolite facies meta-psammopelites, rarely exceed 250 granulite gneiss...

The Tapes Complex crops out in the southeastern Nico Pérez Terrane (NPT) of Río de la Plata Craton and forms part a NE-trending Mesoproterozoic belt together with Calymmian (1.48–1.43 Ga) Parque UTE Mina Verdún groups. complex is characterized by interbedded/tectonically interleaved metasedimentary (mainly siliciclastic) metaultramafic rocks, subordinate intercalations metabasites, carbonate ch...