Carbonate-rich sandstones (samples 0708 and 0704) were collected from outcrop of the Gunflint Formation, Ontario, Canada (sample 0708: 48°29 ′24.4′′ N, 89°11′34.2′′ W; sample 0704: 48°29′24.6′′ N, 89°11′35.3′′ W). Samples contain 0.34 and 0.23wt% organic carbon. The estimated age for the Gunflint Formation is ca. 1.9 Ga (Fralick et al., 2002), and its metamorphic grade is considered to be sub-g...

UNLABELLED The search for indisputable traces of life in Archean cherts is of prime importance. However, their great age and metamorphic history pose constraints on the study of molecular biomarkers. We propose a quantitative criterion to document the thermal maturity of organic matter in rocks in general, and Archean rocks in particular. This is definitively required to select the best candida...

Ophiolites of the Alpine belt derive from closure Mesozoic Tethys Ocean that was interposed between palaeo-Europe and palaeo-Adria continental plates. The orogeny has intensely reworked oceanic rocks into metaophiolites with various metamorphic imprints. In Western Alps, continental-derived units are distributed within two paired bands: An inner band where subduction-related high-pressure (HP) ...

The solubility of uranium (U) in hydrothermal fluid is thought to be controlled by oxidation. In general, mainly transported as U(VI) oxidized fluid, but precipitated U(IV) reduced fluid. However, many geological observations indicate that metamorphic fluids, which are buffered rocks with protoliths such pelite or altered marine basalt, not enriched U. To explore the reason low U we simulated h...

The Dora-Maira massif is an archetypal nappe stack of subducted and exhumed upper crust. Slices continental crust experienced metamorphism at blueschist to ultrahigh-pressure (UHP) eclogite-facies conditions. While the timing peak in UHP unit has been extensively studied, little known about other units. In order constrain conditions high-pressure metamorphism, U-Pb-trace element analyses rutile...

The research at Mendoke Mountains, Southeast Sulawesi Province, particularly for the study of gold deposits, becomes a new challenge because there is no previous detailed study. This aims to analyze characteristics orogenic which include type and texture quartz veins, alteration hydrothermal mineralization with hosted metamorphic rocks. methods used fieldwork laboratory analysis. veins were ide...

Transmission electron microscopy and 3D focused ion beam/scanning microscope nanotomography are applied to grain phase boundaries between quartz, plagioclase, K-feldspar, clinopyroxene, amphibole, calcite. The samples come from metamorphic, plutonic volcanic rocks, hydrothermal experienced cooling decompression after highly variable P–T peak conditions. Most of the partially open in range up se...

There are two basic Fe-rich lithologies at Weld Range: (l) banded iron-formation containing minnesotaite, siderite, quarlz,magnetite, greenalite, stilpnomelane, pyrite, and chamosite with trace amounts of pyrrhotite, arsenopyrite, chalcopyrite, apatite, and rockbridgeite; Q) Fe-shale. which occurs as laminated 2-30cm-thick bands within banded iron-formation, containing chamosite, stilpnomelane,...

The Ciletuh Mélange Complex in West Java, Indonesia, provides evidence of early Cenozoic subduction. This study aims to investigate the stratigraphic position, geological structure, metamorphic facies, and protoliths rock units. research methods employed mapping, petrology, geochemical analysis. samples collected exhibit different including zeolites, greenschist, epidote amphibolite. Protoliths...