Research (Crustal Re-Os Geochronology)
The Yamansu iron deposit, hosted in submarine volcanic rocks, is located in the Aqishan-Yamansu Fe-Cu metallogenic belt of eastern Tianshan, Xinjiang. New pyrite Re-Os, and pyroxene diorite intrusion ages and the chemistry of magnetite constrain the origin of the deposit. The Yamansu orebodies display banded or lenticular forms and sharp contacts with marble and garnet skarn.
Pyrite associated with magnetite from hydrothermal massive ores has a Re-Os isochron age of However, the pyroxene diorite age Magnetite samples from different ores in the Yamansu deposit are suggested to have a magmatic-hydrothermal origin.
Seven Re- Os ages were determined for molybdenite and pyrite samples from two well-dated Precambrian intrusions in Fennoscandia to examine the sustainability of the Re-Os chronometer in a metamorphic and metasomatic setting. Using a new Re decay constant 1. These two localities contain some of the oldest and youngest plutonic activity in Fennoscandia and are associated with newly discovered economic Au mineralization Ilomantsi, Finland and a Cu-Mo prospect Kabeliai, Lithuania. The slightly younger age suggests the introduction of Cu-Mo mineralization by a later phase of the Kabeliai magmatic system.
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Seven ReOs ages were determined for molybdenite and pyrite samples from two well-dated Precambrian intrusions in Fennoscandia to examine the.
America; West of Shetlands oilfields. Selby’s research has developed a unique geochemical toolbox using rhenium, osmium, platinum and palladium that constrain more accurate geological models leading to better reserve predictions. The toolbox provides previously unavailable geological time constraints and source identification of resources e. The underpinning research carried out by Selby TOTAL Reader in Petroleum Geoscience, appointed and his research group at Durham University from appointment to present addresses longstanding academic industry-related issues concerning the development of subsurface Earth resources.
Specifically, exactly when, how and where do resources, such as oil and copper, form in rocks? Analytical and technological advances, developed in part by research at Durham, have permitted the use of previously challenging geochemical methods to help answer old, but critically important geological questions. Selby, his research group and international collaborations 6 PhD students, 2 post-doctoral researchers, United States and Canada Geological Survey research staff; Prof.
As a direct result, Selby’s research has defined and enhanced the precision and understanding of Re-Os and Pd-Pt analytical protocols and elemental behaviour in rocks and minerals. This has improved our understanding of genetic models for both mineral and hydrocarbon systems . In impact terms, the outcome yields critical necessary data required for exploration programmes [Section 4].
Ultimately Selby’s research has shown that the Re-Os system can be applied much more widely than previously thought and has placed Durham at the forefront in the use of this novel research tool both academically and through industry. This leadership was recognised by the award of the William Smith Fund to Selby from the Geological Society of London for excellence in contributions to applied and economic aspects of the science and by the TOTAL petroleum company who fund Selby’s position at Durham.
Direct radiometric dating of hydrocarbon deposits using Rhenium-Osmium isotopes. Science, ,
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– Ma ages given by rhenium-osmium (Re-Os) isotope data for These concordant ages not only date Co-Cu mineralisation, but also place a Zieg, J. Re-Os sulfide (bornite, chalcopyrite, and pyrite) systematics of the.
Mirnejad, H. Economic Geology, 4. ISSN Full text is not posted in this repository. Consult Related URLs below. The Kerman copper belt in Iran contains a number of important porphyry copper deposits, including Sarkuh and Iju. Molybdenite Re-Os isotope dating of the Sarkuh and Iju porphyry copper deposits shows that mineralization occurred at
Canadian Journal of Earth Sciences
Tatsuo Nozaki and Dr. This result supports the ideas of previous studies, indicating that there is a large age gap hiatus in the geologic record of million years and a wide distribution of the Cambrian beds in the Hitachi area. It is expected to provide an important age constraints to reconstruct the initial tectonic history of the Japanese Islands.
Besshi- and Kuroko-type sulfide deposits widely distributed in the Japanese Islands are classified as one of the volcanogenic massive sulfide deposits. Figure 1: Principles of the Re-Os isotope dating method.
Structural characteristics and Re–Os dating of quartz-pyrite veins in the Lewisian Gneiss Complex, NW Scotland: evidence of an early.
These contribute also to an improved understanding of several fundamental geological processes in the field of fault-rock dating, fault mechanics, Re—Os pyrite—chalcopyrite systematics and Early Paleoproterozoic C isotopic fluctuations and geodynamics.
The hydrothermal ore sequence, from early to latest, is: magnetite-hematite-pyrite, molybdenite, bornite-chalcopyrite-pyrite, pyrite-enargite to tennantite-tetrahedrite, covellite, gold. The presence of deep anhydrite vein infill indicates descending acid-sulfate water from shallow steam condensation. The hydrothermal system is chemically characterized by a relatively narrow spectrum of elements enriched compared to bulk continental crust, i. Copper and Sb are enriched by a factor of 10 and 30, respectively.
The arsenic budget is controlled by enargite and fahlore, although pyrite has a constant As abundance of around ppm.
U-Th-Pb dating and high-precision Re-Os ages for molybden- ite from the thermal-stage minerals (molybdenite, chalcopyrite, pyrite, ga- lena, sphalerite, and.
The study area is located at the southern end of the Gorouol greenstone belt, northwestern Niger. This region contains significant deposits of Copper and Molybdenum hosted in intrusive rocks metamorphosed in the green shale facies. This deposit was previously considered a porphyry system of Copper Cu and Molybdenum Mo without having been the subject of advanced research.
The objective of this study is to confirm or refute this hypothesis and to date the mineralisation in an absolute manner in order to readjust the mineralising episode in the history of the West African Craton. The methodology used within the framework of this study is the isotopic dating by the Re-Os method carried out on the pyrites of the host rock. This age range represents the West African Craton scale to an episode of magmatic accretion.
During this accretion, the subduction phenomena between the Crusts Oceanic and Continental would have been favourable for the formation of the Cu and Mo mineralisation of Kourki. Abdou, H. Bonnot, D. Bory Kadey, D.
Dissecting the Re-Os molybdenite geochronometer
The Kerman copper belt in Iran contains a number of important porphyry copper deposits, including Sarkuh and Iju. Molybdenite Re-Os isotope dating of the Sarkuh and Iju porphyry copper deposits shows that mineralization occurred at Compared with the previous Re-Os dating of molybdenite in the region, it is revealed that Cu mineralization was an ongoing process in an arc setting during the Miocene.
and a gentle but deliberate voice said ‘I heard you can date pyrite.’ It was Dick bring Re–Os dating into the field of economic geology and, in turn, shows how.
A concretion is a hard, compact mass of matter formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. The word ‘concretion’ is derived from the Latin con meaning ‘together’ and crescere meaning ‘to grow’. Concretions form within layers of sedimentary strata that have already been deposited.
They usually form early in the burial history of the sediment, before the rest of the sediment is hardened into rock. This concretionary cement often makes the concretion harder and more resistant to weathering than the host stratum. There is an important distinction to draw between concretions and nodules.