Os isotopic compositions in oils show a considerable range, from Os of 1.9–6.0, and they correlate positively with the age of the proposed source rock.
Re/Os ratios also show a large range and overlap the Re/Os ratios found in typical oil source rocks such as organic rich shale.
The gold-producing hydrothermal event is also recorded by Re–Os dating of molybdenite from the gold-bearing Mg-metasomatized metasedimentary and metavolcanic units at the Palokas prospect; a few kilometres from Rompas.
Results of this study confirm that some domains in the structure of uraninite may preserve the original crystallization age, despite an overprinting amphibolite facies metamorphic and other hydrothermal events.
Furthermore, the result also implies that the age of the Gaixian Formation in the Maoling district is older than 2316±40 Ma.Pb ages) and Re–Os dating of molybdenite with data from other geochronological studies completed near the Rompas and Palokas prospects, and comparison of these data with the ages for the major tectonic stages of the Svecofennian orogeny.The Peräpohja belt comprises a greenschist to amphibolite facies; multiply-folded supracrustal sequence of quartzites; mafic volcanics; carbonate rocks; black shales; mica schists and greywackes deposited from ca.Lacustrine sedimentary successions provide exceptionally high-resolution records of continental geological processes, responding to tectonic, climatic and magmatic influences.These successions are therefore essential for correlating geological and climatic phenomena across continents and furthermore the globe.Simplified base map and metamorphic map from the Digi KP Finland geographic information system GIS database of Geological Survey of Finland as of July 2017. Chemical ages shown on this figure are from the same set of samples which were used for in situ U–Pb age dating of uraninite by LA-ICP-MS, and can be found in the electronic Supplement Table S1 in .Thirty-two chemical age datapoints (not shown on this figure) are widely scattered, with low frequencies between 1700 and 400 million years, reflecting the effect of the Phanerozoic lead loss identified in the dataset of the U–Pb age dating.The study supports the utility of in situ U–Pb dating of uraninite and the ability of Re–Os dating to assist in sorting out different hydrothermal events in areas with complex tectonic; magmatic and metamorphic histories. View Full-Text Regional geology and metamorphic zoning in the Peräpohja belt and location of the Rompas Au–U deposit. Chicago/Turabian Style Molnár, Ferenc; O’Brien, Hugh; Stein, Holly; Cook, Nick D. Pb ages) and Re–Os dating of molybdenite with data from other geochronological studies completed near the Rompas and Palokas prospects, and comparison of these data with the ages for the major tectonic stages of the Svecofennian orogeny. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.