IP Policies Research Facilities IIT Kharagpur is widely acclaimed for the quality and breadth of its research enterprise, and particularly for its openness to multidisciplinary research. Several highly rated initiatives represent a long IIT Kharagpur tradition of cross-disciplinary research and collaboration. In this continuous quest for excellence in our research endeavours, we recognize the importance of modernization in infrastructure and experimental facilities. To ensure that we hold on to our position at the cutting edge of innovation, the Institute has set up several state of the art facilities. The lab has established industry standard design and verification flows. More than chips have been designed in this lab, fabricated and successfully tested. Currently more than 60 PhD students and full time MS students work under the ambit of the lab.
The Chadormalu magnetite-apatite deposit in Bafq metallogenic province, Central Iran, is hosted in the late Precambrian-lower Cambrian volcano-sedimentary rocks with sodic, calcic, and potassic alterations characteristic of iron oxide copper-gold IOCG and iron oxide-apatite IOA ore systems. Apatite occurs as scattered irregular veinlets and disseminated grains, respectively, within and in the marginal parts of the main ore-body, as well as apatite-magnetite veins in altered wall rocks.
Our data suggest that hydrothermal magmatic fluids contributed to formation of the primary fluorapatite, and sodic and calcic alterations. The primary apatite reequilibrated with basinal brines in at least two regional extensions and basin developments in Silurian and Triassic in Central Iran. Introduction The formation of apatite-bearing iron deposits is a current topic of debate. The deposits are characterized by large masses of Ti-rich to Ti-poor Fe oxides essentially magnetite and subordinate phosphates, in particular apatite, and are known as Kiruna-type magnetite-apatite e.
U-Th-Pb dating. Analyses were obtained on the Cameca SX Ultrachron at UMass Amherst. In addition, EPMA ages within the uncertainty of the. isotopic age. Ti-in- Trace Element Analyses by EMP: Pb-in-Monazite and New Multipoint Background Method Created Date.
Please complete our online readership survey by clicking the button below We appreciate your comments and feedback so we can continue to improve our magazine. Nevertheless, there are only scarce geochronological data on the timing of formation for the majority of Australian uranium deposits. Because uraninite is commonly a major ore constituent of many primary uranium deposits its geochronology has the potential to provide a direct age of mineralisation.
This contrasts with other geochronological studies of mineral deposits where the age of mineralisation is based on the inference that the dated mineral such as muscovite, biotite, monazite and xenotime crystallised at the same time as the ore. Additionally, the high concentration of uranium in uraninite requires only a relatively short time period for the accumulation of significant concentrations of radiogenic lead. To encourage exploration for uranium, Geoscience Australia researchers undertook dating of selected uranium deposits as a part of its Onshore Energy Security Program to ; Skirrow This article outlines the results from the Kintyre deposit in Western Australia and the Oasis deposit in Queensland where the timing of uranium mineralisation was directly dated using Electron-Probe Micro-analysis EPMA chemical uranium-thorium-lead U-Th-Pb uraninite analysis.
It provides precise and accurate chemical composition for elements Be to U at the micron-scale of a large variety of solid materials such as minerals, glasses, alloys, and ceramics. The primary advantage of EMP analysis is the non-destructive and in-situ character of the analysis. All you need is a well-polished, flat sample, such as a regular petrographic thin section or an epoxy mount.
EMP is the ideal technique for analyzing chemically zoned crystals, for testing a material’s homogeneity, for sampling delicately intermixed phases, or for identifying and characterizing phases chemistry, size, shape. As it is an in-situ technique, information on texture and deformation can be preserved. Acknowledgments The purchase of the JEOL would not have been possible without the help many researchers throughout Colorado and beyond that supported our proposal.
1 THE FIFTH GENERATION ELECTRON PROBE MICRO ANALYSER SX FIVE from CAMECA(France) in CRF, ISM The Central Research Facility (CRF) of Indian School of Mines, Dhanbad has installed Fifth Generation Electron Probe Micro Analyser SX Five from CAMECA France equipped with five Wave length dispersive Spectrometers, BSE Detectors, SE Detectors.
Advanced Search Abstract The growth and dissolution behaviour of detrital, metamorphic and magmatic monazite and zircon during granulite-facies anatexis in pelitic and psammo-pelitic granulites and in garnetiferous granite from the southern margin of the Central Indian Tectonic Zone CITZ have been investigated using reconstructed metamorphic reaction history, monazite electron microprobe dating and sensitive high-resolution ion microprobe SHRIMP U—Pb zircon geochronology.
The meta-psammite additionally records two stages of granulite-facies recrystallization BM2 and BM3. Irrespective of variations in the bulk-rock compositions and peak metamorphic conditions, monazite is highly reactive during the BM1 event, producing complex, chemically zoned crystals. Textural, compositional and chemical ages of these grains indicate the stability of six compositional domains CD1 to CD6 in the paragenetic sequence , of which CD1 represents pre-metamorphic detrital cores of Paleoproterozoic age.
These zircon dates are correlated with the timing of the following: These chronological constraints from monazite and zircon, when integrated with the metamorphic reaction history and published geochronological data, allow recognition of three episodes of granulite-facies metamorphism in the CITZ at Ma pre-BM1 event , between and Ma BM1 event , and between and Ma combined BM2 and BM3 events , as part of a latest Paleoproterozoic to Early Mesoproterozoic orogenic event.
This orogeny is linked to the growth of the Proto-Greater Indian Landmass. Mineral ages, when properly constrained, reveal the timescales of metamorphism, the knowledge of which is central to modeling orogenic processes. Monazite, apart from being an excellent mineral chronometer because of its high Th and U concentrations, high retentivity of radiogenic Pb, low common Pb, and resistance to diffusive Pb loss even under granulite-facies conditions Parrish, ; Cherniak et al.
This is because monazite is extremely reactive during most metamorphic and hydrothermal processes, and can grow, dissolve and recrystallize during prograde and retrograde metamorphism at conditions from greenschist to granulite facies, causing a redistribution of the rare earth elements REE between silicates and phosphates under changing P—T—X conditions Foster et al.
Moreover, interpretation is assisted because the P—T stability limits of metamorphic monazite have been quantitatively determined for certain rock types and compositions in several environments Kelsey et al. Like monazite, there are internal structural and trace element compositional attributes that can be used to distinguish metamorphic from igneous zircon Rubatto, ; Corfu et al.
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Detail of the specifications of EPMA is as follows: Up to 10 uA Beam Stability: Up to 1 uA Beam Stability: Because the wavelengths of these X-rays are characteristic of the emitting species, the sample composition can be easily identified by recording WDS spectra Wavelength Dispersive Spectroscopy. WDS spectrometers are based on the Bragg’s law and use various moveable, shaped monocrystals as monochromators.
EPMA is a fully qualitative and quantitative method of non-destructive elemental analysis of micron-sized volumes at the surface of materials, with sensitivity at the level of ppm.
An electron probe micro analyzer (EPMA) has been used to measure the U–Th–Pb ages of more than 15, Key words: monazite, age, sandstone, Japanese Islands Introduction The Japanese Islands are composed of com- formed by comparing data obtained by EPMA dating with those acquired by the SHRIMP tech-nique (e.g. Santosh et al.,
It is supplementary to a seismic profile, which runs north-south through the Indian peninsula towards Sri Lanka. This profile intersects major shear zones and possible suture zones separating distinct crustal terrains of the Pan-African East African – Antarctic Orogen formed during the assembly of Gondwana. The aim of this petrological-structural-geochronological project is to unravel the formation and tectono-metamorphic evolution of the Madurai Block of the Southern Granulate Terrain of India, which is bounded by the Palghat-Cauvery shear zone a possible suture in the north and by the Achankovil shear zone in the south.
The results will help to understand the geodynamic evolutions that affected the Madurai block during the formation of the supercontinent Gondwana and possibly that of Rodinia. The definition and recognition of specific crustal domains and the knowledge of their tectono-metamorphic evolution will contribute to the interpretation of seismic data along the profile. In addition, the results will help to correlate crustal domains in the now dispersed crustal fragments of the Gondwana supercontinent.
CU Boulder â Electron Microprobe Laboratory – JEOL JXA-8230
Monazite TS-Mnz is reddish brown with initial weight of The TS-Mnz in high-contrast BSE-imaging demonstrates homogeneous, clear domains, and domains including numerous inclusions. The TS-Mnz contains 4. Monazite ANK-Mnz is significantly larger, with an initial weight of g.
instrument, and a special focus on monazite geochronology by EPMA. The student will have the opportunity during the 1- or 3-day workshop to think about his/her own .
Lu-Hf geochronology and trace element distribution in garnet: Implications for uplift and exhumation of ultra-high pressure granuites in the Sudetes, SW Poland. Ilmenite-bearing eclogites of the West Sudetes – their geochemistry and mineral chemistry. Nd and Sr age and isotope patterns from Variscan eclogites of the eastern Bohemian Massif. Annales Societatis Geologorum Poloniae, Crustal influx, indentation, ductile thinning and gravity redistribution in a continental wedge: Th diffusion in monazite.
Pb diffusion in zircon. Pb diffusion in monazite: Geochimica et Cosmochimica Acta, Mixing properties of phengitic micas and revised garnet-phengite thermobarometers.
Progress in the project – a fleeting summary
Dumplin on west, Central Maine and Conant Brook on east of opposing shear sense enclosing the Monson orthogneiss. Research was designed to establish the timing of deformation to test the hypothesis that strain in transpressional systems occurs contemporaneously. An understanding of the timing of deformation in this zone could elucidate the mechanisms that formed the zone and contribute to a greater overall understanding of fabric evolution in transpressional systems.
Plutons that contain all fabrics associated with progressive transpression — lineations ranging from subhorizontal initial to steeply-plunging parallel to dip final — mark the maximum age of deformation.
Abstract. Th – U – Pb electron microprobe (EPMA) dating of mainly detrital monazite from the Quamby Conglomerate in the Eastern Succession of the Mt Isa inlier reveals three distinct monazite growth/recrystallisation events at around , and Ma.
Advanced Search Abstract Ages of detrital monazite and zircon from alluvium collected from the French Broad River drainage basin, an orogen-crossing main trunk river, and alluvium in first-order tributary streams, provide an unconventional perspective for examining the regional tectonic and metamorphic history of the southern Appalachian orogen eastern United States. The French Broad River system samples migmatitic Ashe—Tallulah Falls suite paragneisses with inferred Neoproterozoic clastic protoliths of the Eastern Blue Ridge and western Inner Piedmont, Mesoproterozoic basement orthogneisses, numerous Paleozoic metaplutonic gneisses, and tectonite equivalents of these lithologies in the Brevard fault zone.
Middle Ordovician ages dominate the monazite age spectrum. Monazite from tributaries has a dominant Pb Th age peak ca. Electron microprobe total Th-U-Pb chemical ages for selected tributary monazite grains also analyzed by ion microprobe reveal additional monazite growth events i. Tributary and French Broad River zircon age spectra are dominated by Mesoproterozoic and Ordovician grains.
Rare Neoproterozoic ages of — Ma and — Ma are present in all zircon data sets.
CU Boulder â Electron Microprobe Laboratory – JEOL JXA-8230
The terrane is underlain by heterogeneous isobarically cooled orthogneisses termed the Mary batholith. A transect across the batholith documents early, penetrative subhorizontal to gently dipping gneissic foliation S1. L1 coincides with garnet aggregates, elongate mafic enclaves, and core-and-mantle structure in feldspar porphyroclasts. Lineations are coaxial with hinges of isoclinally folded layering F1. L1 is interpreted as a composite mineral lineation with intersection and stretching components.
Kinematics are uniformly top-to-the-ESE.
Two monazite crystals from Madagascar, TS-Mnz (Tsaratanana) and ANK-Mnz (Ankazobe) supplied by a mineral dealer, were evaluated in terms of their potential as reference materials for U-Pb isotope and Th-U-total Pb EPMA dating.
It remains a matter of debate whether the formation of domes was related to the well-documented late orogenic extension or to the contractional tectonics that preceded. Migmatization and magmatism are expected to predate extension if the domes are compression-related regional anticlines, but they must both precede and be contemporaneous with extension if they are extensional core complexes. In the Montagne Noire area southern French Massif Central , where migmatization, magmatism and the deformation framework are well documented, the age of the extensional event was unequivocally constrained to — Ma.
Therefore, dating migmatization in this area is a key point for discriminating between the two hypotheses and understanding the Late Palaeozoic evolution of this part of the Variscan belt. Although zircon did not record any Variscan age unequivocally related to compression Ma , two age groups were identified from the monazite crystals. A first event, at ca. A second event at ca.
The ages of these two events post-date the Variscan compression and agree with an overall extensional context for the development of the Montagne Noire dome-shaped massif. Comparison of these results with published chemical EPMA dating of monazite from the same rocks demonstrates that the type of statistical treatment applied to EPMA data is crucial in order to resolve different monazite age populations.
For the first time petrology is used to quantify the pressure difference between two stacked units in the Western Alps.
CU Boulder â Electron Microprobe Laboratory – JEOL JXA-8230
Geology, Geophysics and Environment 44, 1, Mineralogia – Special Papers, 47, Acta Mineralogica-Petrographica 32, Mineralogia – Special Papers, 45, Wyzwania polskiej geologii, 3. Polski Kongres Geologiczny,
Halpin JA, Jensen T, McGoldrick P, Meffre S, Berry RF, et al., ‘Authigenic monazite and detrital zircon dating from the Proterozoic Rocky Cape Group, Tasmania: links to the Belt-Purcell Supergroup, North America’, Precambrian Research, pp.
The Igralishte pluton Ograzhden block, Serbo-Macedonian massif is built-up of twomica S-type granite with age of The most significant alterations of the plutonic rocks are caused by postmagmatic high-temperature alkaline K and Na metasomatism. Besides, a tectonic and hydrothermal overprint at Monazite brings clear signs of hydrothermal alteration being presented by randomly shaped relics of the mineral surrounded by pseudomorphic dispersed aggregates of secondary products.
In backscattered electron BSE images these aggregates appear as much darker areas than those of the monazite relics and contain very small lighter spots with increased content of Th, REE, Si and Y. According to EPMA data, the major part of the aggregates corresponds to apatite containing variable quantity of britholite molecule. Beside the pseudomorphic replacement of monazite, in the internal parts of the monazite relics in fissures there are a lot of inclusions of thorite and xenotime.
The perfomed EPMA dating of the thorite and xenotime, although giving wide variation in the age Ma , evidences their formation due to the postmagmatic hightemperature hydrothermal process and alteration of monazite. Two types of monazite particles were found during transmission electron microscopy TEM examination: These data indicate that at least on the early stage of the monazite breakdown, mainly the PO4 sublattice of the mineral is affected by hydrothermal alteration – through the substitution of P by Si.
This process can be considered as britholitization of monazite. The inspection of series of particles of the polycrystalline monazite allows establishing that they are not composed of randomly oriented domains. This fact is illustrated by a case particle whose polycrystalline SAED pattern is superposition and derivative of series of slightly rotated and inclined SAED patterns originated from one and the same [ ] zone.
The obtained results allows one to suggest that the observed microstructure of the polycrystalline monazite is a manifestation of original mosaic microstructure of the mineral but influenced by the later alteration processes.