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Olierook HKH, Fougerouse D, Doucet LS, Liu Y, Rayner MJ, Danišík M, Condon DJ, McInnes BIA, Jaques AL, Evans NJ, McDonald BJ, Li ZX, Kirkland CL, Mayers C, Wingate MTD. Emplacement of the Argyle diamond deposit into an ancient rift zone triggered by supercontinent breakup. Nat Commun 2023; 14:5274. [PMID: 37726314 PMCID: PMC10509175 DOI: 10.1038/s41467-023-40904-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 08/14/2023] [Indexed: 09/21/2023] Open
Abstract
Argyle is the world's largest source of natural diamonds, yet one of only a few economic deposits hosted in a Paleoproterozoic orogen. The geodynamic triggers responsible for its alkaline ultramafic volcanic host are unknown. Here we show, using U-Pb and (U-Th)/He geochronology of detrital apatite and detrital zircon, and U-Pb dating of hydrothermal titanite, that emplacement of the Argyle lamproite is bracketed between 1311 ± 9 Ma and 1257 ± 15 Ma (2σ), older than previously known. To form the Argyle lamproite diatreme complex, emplacement was likely driven by lithospheric extension related to the breakup of the supercontinent Nuna. Extension facilitated production of low-degree partial melts and their migration through transcrustal corridors in the Paleoproterozoic Halls Creek Orogen, a rheologically-weak rift zone adjacent to the Kimberley Craton. Diamondiferous diatreme emplacement during (super)continental breakup may be prevalent but hitherto under-recognized in rift zones at the edges of ancient continental blocks.
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Affiliation(s)
- Hugo K H Olierook
- Timescales of Mineral Systems Group, School of Earth and Planetary Sciences, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia.
- John de Laeter Centre, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia.
| | - Denis Fougerouse
- School of Earth and Planetary Sciences, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
| | - Luc S Doucet
- Earth Dynamics Research Group, School of Earth and Planetary Sciences and The Institute for Geoscience Research (TIGeR), Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
- State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, Hubei, 430074, China
| | - Yebo Liu
- Earth Dynamics Research Group, School of Earth and Planetary Sciences and The Institute for Geoscience Research (TIGeR), Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
| | | | - Martin Danišík
- John de Laeter Centre, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
| | - Daniel J Condon
- British Geological Survey, Keyworth, Nottingham, NG12 5GG, UK
| | - Brent I A McInnes
- John de Laeter Centre, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
| | - A Lynton Jaques
- Research School of Earth Sciences, Australian National University, Canberra ACT, 2000, Australia
| | - Noreen J Evans
- John de Laeter Centre, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
| | - Bradley J McDonald
- John de Laeter Centre, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
| | - Zheng-Xiang Li
- Earth Dynamics Research Group, School of Earth and Planetary Sciences and The Institute for Geoscience Research (TIGeR), Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
- Laoshan Laboratory, 266237, Qingdao, China
| | - Christopher L Kirkland
- Timescales of Mineral Systems Group, School of Earth and Planetary Sciences, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
| | - Celia Mayers
- John de Laeter Centre, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
| | - Michael T D Wingate
- John de Laeter Centre, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
- Geological Survey of Western Australia, 100 Plain Street, East Perth, WA, 6004, Australia
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Audétat A, Schmitt AK, Njul R, Saalfeld M, Borisova A, Lu Y. New constraints on Ti diffusion in quartz and the priming of silicic volcanic eruptions. Nat Commun 2023; 14:4277. [PMID: 37460528 DOI: 10.1038/s41467-023-39912-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 07/04/2023] [Indexed: 07/20/2023] Open
Abstract
Titanium diffusion profiles in quartz crystals are widely applied to constrain the duration of magmatic processes. However, experimentally determined Ti diffusion coefficients in quartz diverge by three orders of magnitude. To rectify this problem we derive Ti diffusion coefficients from natural quartz phenocrysts from the 1991 eruption at Mt. Pinatubo, by combining U-Th ages of small (15-40 µm long) zircon inclusions with Ti diffusion profiles measured at nearby growth zone contacts in the same quartz crystals. Application of the obtained data to quartz crystals with Ti-rich rims from thirteen silicic volcanic tuffs worldwide suggests that the magmas erupted years to thousands of years after magma chamber rejuvenation, with the priming time increasing with magma volume and decreasing temperature. Here we show that the time scales involved in the generation of silicic volcanic eruptions are much longer than originally thought.
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Affiliation(s)
- Andreas Audétat
- Bayerisches Geoinstitut, University of Bayreuth, Bayreuth, Germany.
| | - Axel K Schmitt
- Heidelberg University, Heidelberg, Germany
- Curtin University, Perth, Australia
| | - Raphael Njul
- Bayerisches Geoinstitut, University of Bayreuth, Bayreuth, Germany
| | | | - Anastassia Borisova
- Géosciences Environnement Toulouse, University of Toulouse, CNRS, Toulouse, France
| | - Yongjun Lu
- Geological Survey of Western Australia, Department of Mines, Industry Regulation and Safety, Perth, Australia
- Centre for Exploration Targeting and School of Earth Sciences, University of Western Australia, Crawley, Australia
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Bindeman IN, Melnik OE, Guillong M, Utkin IS, Wotzlaw JF, Schmitt AK, Stern RA. Age of the magma chamber and its physicochemical state under Elbrus Greater Caucasus, Russia using zircon petrochronology and modeling insights. Sci Rep 2023; 13:9733. [PMID: 37322072 PMCID: PMC10272178 DOI: 10.1038/s41598-023-36793-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 06/12/2023] [Indexed: 06/17/2023] Open
Abstract
Mount Elbrus, Europe's tallest and largely glaciated volcano, is made of silicic lavas and is known for Holocene eruptions, but the size and state of its magma chamber remain poorly constrained. We report high spatial resolution U-Th-Pb zircon ages, co-registered with oxygen and hafnium isotopic values, span ~ 0.6 Ma in each lava, documenting magmatic initiation that forms the current edifice. The best-fit thermochemical modeling constrains magmatic fluxes at 1.2 km3/1000 year by hot (900 °C), initially zircon-undersaturated dacite into a vertically extensive magma body since ~ 0.6 Ma, whereas a volcanic episode with eruptible magma only extends over the past 0.2 Ma, matching the age of oldest lavas. Simulations explain the total magma volume of ~ 180 km3, temporally oscillating δ18O and εHf values, and a wide range of zircon age distributions in each sample. These data provide insights into the current state (~ 200 km3 of melt in a vertically extensive system) and the potential for future activity of Elbrus calling for much-needed seismic imaging. Similar zircon records worldwide require continuous intrusive activity by magmatic accretion of silicic magmas generated at depths, and that zircon ages do not reflect eruption ages but predate them by ~ 103 to 105 years reflecting protracted dissolution-crystallization histories.
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Affiliation(s)
- I N Bindeman
- Earth Sciences, University of Oregon, Eugene, OR, USA.
| | - O E Melnik
- Institute of Mechanics, Lomonosov Moscow State University, Moscow, Russia
- Institut des Sciences de la Terre (ISTerre), University Grenoble Alpes, Grenoble, France
| | - M Guillong
- Department of Earth Sciences, ETH Zurich, Zurich, Switzerland
| | - I S Utkin
- Institute of Mechanics, Lomonosov Moscow State University, Moscow, Russia
- Department of Civil, Environmental and Geomatic Engineering, ETH Zürich, Zürich, Switzerland
| | - J-F Wotzlaw
- Department of Earth Sciences, ETH Zurich, Zurich, Switzerland
| | - A K Schmitt
- Institut für Geowissenschaften, Universität Heidelberg, Heidelberg, Germany
- John de Laeter Centre, Curtin University, Bentley, WA, Australia
| | - R A Stern
- Canadian Centre for Isotopic Microanalysis, University of Alberta, Edmonton, Canada
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Mateo L, Tornos F, Hanchar JM, Villa IM, Stein HJ, Delgado A. The Montecristo mining district, northern Chile: the relationship between vein-like magnetite-(apatite) and iron oxide-copper-gold deposits. MINERALIUM DEPOSITA 2023; 58:1023-1049. [PMID: 37426339 PMCID: PMC10329088 DOI: 10.1007/s00126-023-01172-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 03/17/2023] [Indexed: 07/11/2023]
Abstract
The Montecristo district, northern Chile, is one of the few places worldwide where there is a direct relationship between magnetite-(apatite) (MtAp) mineralization and iron oxide-copper-gold (IOCG) mineralization. The MtAp mineralization includes Ti-poor magnetite, fluorapatite, and actinolite and is crosscut and partially replaced by a younger IOCG mineralization that includes a second generation of actinolite and magnetite with quartz, chalcopyrite, pyrite, and molybdenite. The MtAp stage at Montecristo is interpreted as the crystallized iron-rich melts that used the pre-existing structures of the Atacama Fault System as conduits. These rocks later acted as a trap for hydrothermal IOCG mineralization. Geochronology data at Montecristo indicate that the host diorite (U-Pb zircon 153.3 ± 1.8 Ma, 2-sigma), MtAp mineralization (40Ar-39Ar in actinolite, 154 ± 2 Ma and 153 ± 4 Ma, 2-sigma), and the IOCG event (Re-Os on molybdenite, 151.8 ± 0.6 Ma, 2-sigma) are coeval within error and took place in a time span of less than 3.4 Ma. The εHfi and εNdi values of the host diorite are + 8.0 to + 9.8 and + 4.3 to + 5.4, respectively. The whole-rock 87Sr/86Sri values of the IOCG mineralization (0.70425 to 0.70442) are in the lower end of those of the MtAp mineralization (0.70426-0.70629). In contrast, εNdi values for the IOCG mineralization (+ 5.4 and + 5.7) fall between those of the MtAp rocks (+ 6.6 to + 7.2) and the host diorite, which suggests that the IOCG event was related to fluids having a more crustal Nd (εNdi < + 5.7) composition than the MtAp mineralization. This likely reflects the mixing of Nd from the MtAp protolith and a deep magmatic-hydrothermal source, very likely an unexposed intrusion equivalent to the host diorite. Sulfur isotope compositions (δ34S, + 0.3 to + 3.4‰) are consistent with a magmatic source. Supplementary Information The online version contains supplementary material available at 10.1007/s00126-023-01172-0.
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Affiliation(s)
- Laura Mateo
- Department of Earth Sciences, Memorial University of Newfoundland, St. John’s, NL A1B 3X5 Canada
| | - Fernando Tornos
- Department of Earth Sciences, Memorial University of Newfoundland, St. John’s, NL A1B 3X5 Canada
- Instituto de Geociencias (CSIC-UCM), 28040 Madrid, Spain
| | - John M. Hanchar
- Department of Earth Sciences, Memorial University of Newfoundland, St. John’s, NL A1B 3X5 Canada
| | - Igor M. Villa
- Institut Fürr Geologie, Universität Bern, 3012 Bern, Switzerland
- Centro Universitario Datazioni E Archeometria, Università Di Milano Bicocca, 20126 Milan, Italy
| | - Holly J. Stein
- Applied Isotope Research for Industry and Environment, AIRIE, Fort Collins, CO 80524 USA
- Department of Geosciences, University of Oslo, 0316 Oslo, Norway
| | - Antonio Delgado
- Laboratorio de Biogeoquímica de Isotopos Estables, Instituto Andaluz de Ciencias de La Tierra IACT (CSIC-UGR), 18100 Granada, Spain
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Chowdhury W, Trail D, Miller M, Savage P. Eoarchean and Hadean melts reveal arc-like trace element and isotopic signatures. Nat Commun 2023; 14:1140. [PMID: 36854670 PMCID: PMC9975215 DOI: 10.1038/s41467-023-36538-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 02/07/2023] [Indexed: 03/02/2023] Open
Abstract
Constraining the lithological diversity and tectonics of the earliest Earth is critical to understanding our planet's evolution. Here we use detrital Jack Hills zircon (3.7 - 4.2 Ga) analyses coupled with new experimental partitioning data to model the silica content, Si+O isotopic composition, and trace element contents of their parent melts. Comparing our derived Jack Hills zircons' parent melt Si+O isotopic compositions (-1.92 ≤ δ30SiNBS28 ≤ 0.53 ‰; 5.23 ≤ δ18OVSMOW ≤ 9.00 ‰) to younger crustal lithologies, we conclude that the chemistry of the parent melts was influenced by the assimilation of terrigenous sediments, serpentinites, cherts, and silicified basalts, followed by igneous differentiation, leading to the formation of intermediate to felsic melts in the early Earth. Trace element measurements also show that the formational regime had an arc-like chemistry, implying the presence of mobile-lid tectonics in the Hadean. Finally, we propose that these continental-crust forming processes operated uniformly from 4.2 to at least 3.7 Ga.
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Affiliation(s)
- Wriju Chowdhury
- Department of Earth & Environmental Sciences, University of Rochester, Rochester, NY, 14627, USA.
| | - Dustin Trail
- grid.16416.340000 0004 1936 9174Department of Earth & Environmental Sciences, University of Rochester, Rochester, NY 14627 USA
| | - Martha Miller
- grid.16416.340000 0004 1936 9174Department of Earth & Environmental Sciences, University of Rochester, Rochester, NY 14627 USA
| | - Paul Savage
- grid.11914.3c0000 0001 0721 1626School of Earth and Environmental Sciences, University of St Andrews, Bute Building, St Andrews, Scotland KY16 9TS UK
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Sources of Hydrothermal Fluids Inferred from Oxygen and Carbon Isotope Composition of Calcite, Keweenaw Peninsula Native Copper District, Michigan, USA. MINERALS 2022. [DOI: 10.3390/min12040474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
The Mesoproterozoic North American Midcontinent Rift hosts the world’s largest accumulation of native copper in Michigan’s Keweenaw Peninsula. During a regional metamorphogenic-hydrothermal event, native copper was deposited along with spatially zoned main-stage minerals in a thermal high. This was followed by deposition of late-stage minerals including minor copper sulfide. Inferences from the oxygen and carbon isotopic composition of main-stage hydrothermal fluids, as calculated from 296 new and compiled isotopic measurements on calcite, are consistent with existing models that low-sulfur saline native copper ore-forming fluids were dominantly derived by burial metamorphic processes from the very low sulfur basalt-dominated rift fill at depth below the native copper deposits. Co-variation of oxygen and carbon isotopic compositions are consistent with mixing of metamorphic-derived fluids with two additional isotopically different fluids. One of these is proposed to be evolved seawater that provided an outside source of salinity. This fluid mixed at depth and participated in the formation of a well-mixed hybrid metamorphic-dominated ore-forming fluid. Secondary Ion Mass Spectrometry in-situ isotopic analyses of calcite demonstrate a high degree of variability within samples that is attributed to variable degrees of shallow mixing of the hybrid ore-forming fluid with sulfur-poor, reduced evolved meteoric water in the zone of precipitation. The oxygen and carbon isotopic compositions of 100 new and compiled measurements on late-stage calcite are mostly isotopically different than the main-stage hydrothermal fluids. The late-stage hydrothermal fluids are interpreted as various proportions of mixing of evolved meteoric water, main-stage hybrid ore-forming fluid, and shallow, evolved seawater in the relatively shallow zone of precipitation.
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Record of Crustal Thickening and Synconvergent Extension from the Dajiamang Tso Rift, Southern Tibet. GEOSCIENCES 2021. [DOI: 10.3390/geosciences11050209] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
North-trending rifts throughout south-central Tibet provide an opportunity to study the dynamics of synconvergent extension in contractional orogenic belts. In this study, we present new data from the Dajiamang Tso rift, including quantitative crustal thickness estimates calculated from trace/rare earth element zircon data, U-Pb geochronology, and zircon-He thermochronology. These data constrain the timing and rates of exhumation in the Dajiamang Tso rift and provide a basis for evaluating dynamic models of synconvergent extension. Our results also provide a semi-continuous record of Mid-Cretaceous to Miocene evolution of the Himalayan-Tibetan orogenic belt along the India-Asia suture zone. We report igneous zircon U-Pb ages of ~103 Ma and 70–42 Ma for samples collected from the Xigaze forearc basin and Gangdese Batholith/Linzizong Formation, respectively. Zircon-He cooling ages of forearc rocks in the hanging wall of the Great Counter thrust are ~28 Ma, while Gangdese arc samples in the footwalls of the Dajiamang Tso rift are 16–8 Ma. These data reveal the approximate timing of the switch from contraction to extension along the India-Asia suture zone (minimum 16 Ma). Crustal-thickness trends from zircon geochemistry reveal possible crustal thinning (to ~40 km) immediately prior to India-Eurasia collision onset (58 Ma). Following initial collision, crustal thickness increases to 50 km by 40 Ma with continued thickening until the early Miocene supported by regional data from the Tibetan Magmatism Database. Current crustal thickness estimates based on geophysical observations show no evidence for crustal thinning following the onset of E–W extension (~16 Ma), suggesting that modern crustal thickness is likely facilitated by an underthrusting Indian lithosphere balanced by upper plate extension.
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Martínez C, Jaramillo C, Correa-Metrío A, Crepet W, Moreno JE, Aliaga A, Moreno F, Ibañez-Mejia M, Bush MB. Neogene precipitation, vegetation, and elevation history of the Central Andean Plateau. SCIENCE ADVANCES 2020; 6:eaaz4724. [PMID: 32923618 PMCID: PMC7455194 DOI: 10.1126/sciadv.aaz4724] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 07/14/2020] [Indexed: 05/26/2023]
Abstract
Andean uplift played a fundamental role in shaping South American climate and species distribution, but the relationship between the rise of the Andes, plant composition, and local climatic evolution is poorly known. We investigated the fossil record (pollen, leaves, and wood) from the Neogene of the Central Andean Plateau and documented the earliest evidence of a puna-like ecosystem in the Pliocene and a montane ecosystem without modern analogs in the Miocene. In contrast to regional climate model simulations, our climate inferences based on fossil data suggest wetter than modern precipitation conditions during the Pliocene, when the area was near modern elevations, and even wetter conditions during the Miocene, when the cordillera was around ~1700 meters above sea level. Our empirical data highlight the importance of the plant fossil record in studying past, present, and future climates and underscore the dynamic nature of high elevation ecosystems.
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Affiliation(s)
- C. Martínez
- Plant Biology Section, School of Integrative Plant Sciences, Cornell University, 412 Mann Library Building, Ithaca, NY 14853, USA
- Smithsonian Tropical Research Institute, Unit 0948, APO AA 34002, Balboa, Ancon 084303092, Panama
| | - C. Jaramillo
- Smithsonian Tropical Research Institute, Unit 0948, APO AA 34002, Balboa, Ancon 084303092, Panama
- ISEM, U. Montpellier, CNRS, EPHE, IRD, Montpellier, France
| | - A. Correa-Metrío
- Instituto de Geología, Universidad Nacional Autónoma de México, Ciudad de México 04520, México
| | - W. Crepet
- Plant Biology Section, School of Integrative Plant Sciences, Cornell University, 412 Mann Library Building, Ithaca, NY 14853, USA
| | - J. E. Moreno
- Smithsonian Tropical Research Institute, Unit 0948, APO AA 34002, Balboa, Ancon 084303092, Panama
| | - A. Aliaga
- Departamento de Paleontología de Vertebrados, Museo de Historia Natural LimaUNMSM, Av. Arenales 1256, Jesús María, Lima, Perú
| | - F. Moreno
- Earth and Environmental Sciences, University of Rochester, 227 Hutchison Hall, University of Rochester, Rochester, NY 14627, USA
| | - M. Ibañez-Mejia
- Earth and Environmental Sciences, University of Rochester, 227 Hutchison Hall, University of Rochester, Rochester, NY 14627, USA
| | - M. B. Bush
- Ocean Engineering and Marine Sciences, Florida Institute of Technology, 225 Harris Building, Melbourne, FL, 32901, USA
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The Medicine Hat Block and the Early Paleoproterozoic Assembly of Western Laurentia. GEOSCIENCES 2020. [DOI: 10.3390/geosciences10070271] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The accretion of the Wyoming, Hearne, and Superior Provinces to form the Archean core of western Laurentia occurred rapidly in the Paleoproterozoic. Missing from Hoffman’s (1988) original rapid aggregation model was the Medicine Hat block (MHB). The MHB is a structurally distinct, complex block of Precambrian crystalline crust located between the Archean Wyoming Craton and the Archean Hearne Province and overlain by an extensive Phanerozoic cover. It is distinguished on the basis of geophysical evidence and limited geochemical data from crustal xenoliths and drill core. New U-Pb ages and Lu-Hf data from zircons reveal protolith crystallization ages from 2.50 to 3.28 Ga, magmatism/metamorphism at 1.76 to 1.81 Ga, and εHfT values from −23.3 to 8.5 in the Archean and Proterozoic rocks of the MHB. These data suggest that the MHB played a pivotal role in the complex assembly of western Laurentia in the Paleoproterozoic as a conjugate or extension to the Montana Metasedimentary Terrane (MMT) of the northwestern Wyoming Province. This MMT–MHB connection likely existed in the Mesoarchean, but it was broken sometime during the earliest Paleoproterozoic with the formation and closure of a small ocean basin. Closure of the ocean led to formation of the Little Belt arc along the southern margin of the MHB beginning at approximately 1.9 Ga. The MHB and MMT re-joined at this time as they amalgamated into the supercontinent Laurentia during the Great Falls orogeny (1.7–1.9 Ga), which formed the Great Falls tectonic zone (GFTZ). The GFTZ developed in the same timeframe as the better-known Trans-Hudson orogen to the east that marks the merger of the Wyoming, Hearne, and Superior Provinces, which along with the MHB, formed the Archean core of western Laurentia.
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Friedrichs B, Schmitt AK, McGee L, Turner S. U–Th whole rock data and high spatial resolution U–Th disequilibrium and U–Pb zircon ages of Mt. Erciyes and Mt. Hasan Quaternary stratovolcanic complexes (Central Anatolia). Data Brief 2020; 29:105113. [PMID: 32021883 PMCID: PMC6994622 DOI: 10.1016/j.dib.2020.105113] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 12/11/2019] [Accepted: 01/03/2020] [Indexed: 11/17/2022] Open
Abstract
Thirty-eight lava and pyroclastic samples were collected from Mt. Erciyes and Mt. Hasan, the two largest stratovolcanic complexes of the Central Anatolian Volcanic Province in Turkey. More than 1000 zircon crystals were dated by Secondary Ion Mass Spectrometry (SIMS) applying U–Th disequilibrium and U–Pb methods. Model ages were calculated from zircon 230Th–238U–232Th isotopic compositions in combination with U–Th whole rock data of digested lava samples generated by Multi-Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICP-MS). Middle and Late Pleistocene ages dominate the dataset, but are complemented by both older (predominantly Early Pleistocene) and younger (Holocene) ages. U–Th disequilibrium and U–Pb zircon data provide maximum eruption ages that can be further specified by (U–Th)/He geochronology (zircon double dating). Additionally, these data are important to constrain the longevity and size of magmatic systems, and their potential for reactivation leading to potentially hazardous eruptions.
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Affiliation(s)
- Bjarne Friedrichs
- Institute of Earth Sciences, Heidelberg University, Germany
- Corresponding author. Institute of Earth Sciences, Heidelberg University, Im Neuenheimer Feld 234-236, 69120, Heidelberg, Germany.
| | | | - Lucy McGee
- Department of Earth and Planetary Sciences, Macquarie University, Sydney, Australia
- Department of Earth Sciences, University of Adelaide, Australia
| | - Simon Turner
- Department of Earth and Planetary Sciences, Macquarie University, Sydney, Australia
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Provenance and Tectonic Implications of Sedimentary Rocks of the Paleozoic Chiron Basin, Eastern Transbaikalia, Russia, Based on Whole-Rock Geochemistry and Detrital Zircon U–Pb Age and Hf Isotopic Data. MINERALS 2020. [DOI: 10.3390/min10030279] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The Chiron Basin extends along the southern periphery of the Siberian Craton and the western margin of the Mongol–Okhotsk Belt. Here, we present whole-rock geochemical data (major and trace elements and Sm–Nd isotopes) along with zircon U–Pb geochronology and Lu–Hf isotopic data from Paleozoic sedimentary rocks within the Chiron Basin to investigate their provenance and tectonic history. εNd(t) values of the siliciclastics rocks of the Khara–Shibir, Shazagaitui, and Zhipkhoshi formations vary from −17.8 to −6.6, with corresponding two-stage Nd model ages (tNd(C)) ranging from 2.56 to 1.65 Ga. Detrital zircon grains from these rocks are predominantly Archean, Paleoproterozoic, and Carboniferous–Devonian in age. The data suggest that the southern flank of the Siberian Craton is the only viable source area for Archean and Paleoproterozoic zircon grains with Hf model ages (tHf(C)) of >2.20 Ga. The majority of zircon grains from sandstones from the Khara–Shibir, Shazagaitui, and Zhipkhoshi formations are Devonian–Carboniferous in age. With respect to their Hf model ages, the zircon grains can be subdivided into two groups. The first group of Devonian–Carboniferous zircon grains is characterized by relatively old (mainly Paleoproterozoic) tHf(C) model ages of 2.25–1.70 Ga and the source was the southern margin of the Siberian Craton. The second group of Devonian–Carboniferous zircon grains is characterized by significantly younger (mainly Neoproterozoic) tHf(C) model ages of 1.35–0.36 Ga, which are consistent with a juvenile source, most likely eroded island arcs. Our data, show that sedimentary rocks of the Chiron Basin likely formed in a back-arc basin on the southern periphery of the Siberian Craton facing the Paleozoic Mongol–Okhotsk Ocean.
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12
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Ibañez-Mejia M, Tissot FLH. Extreme Zr stable isotope fractionation during magmatic fractional crystallization. SCIENCE ADVANCES 2019; 5:eaax8648. [PMID: 31897427 PMCID: PMC6920019 DOI: 10.1126/sciadv.aax8648] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 11/04/2019] [Indexed: 06/10/2023]
Abstract
Zirconium is a commonly used elemental tracer of silicate differentiation, yet its stable isotope systematics remain poorly known. Accessory phases rich in Zr4+ such as zircon and baddeleyite may preserve a unique record of Zr isotope behavior in magmatic environments, acting both as potential drivers of isotopic fractionation and recorders of melt compositional evolution. To test this potential, we measured the stable Zr isotope composition of 70 single zircon and baddeleyite crystals from a well-characterized gabbroic igneous cumulate. We show that (i) closed-system magmatic crystallization can fractionate Zr stable isotopes at the >0.5% level, and (ii) zircon and baddeleyite are isotopically heavy relative to the melt from which they crystallize, thus driving chemically differentiated liquids toward isotopically light compositions. Because these effects are contrary to first-order expectations based on mineral-melt bonding environment differences, Zr stable isotope fractionation during zircon crystallization may not solely be a result of closed-system thermodynamic equilibrium.
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Affiliation(s)
- Mauricio Ibañez-Mejia
- Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY 14627, USA
| | - François L. H. Tissot
- The Isotoparium, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
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LKZ-1: A New Zircon Working Standard for the In Situ Determination of U–Pb Age, O–Hf Isotopes, and Trace Element Composition. MINERALS 2019. [DOI: 10.3390/min9050325] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This study introduces a new zircon reference material, LKZ-1, for the in situ U–Pb dating and O–Hf isotopic and trace element analyses. The secondary ion mass spectrometric analyses for this gem-quality single-crystal zircon yielded a weighted mean 206Pb/238U age of 572.6 ± 2.0 Ma (2σ, n = 22, MSWD = 0.90), with moderately high U concentrations (619 ± 21 ppm, 1 SD), restricted Th/U ratios (0.146 ± 0.002, 1 SD), and negligible common Pb content (206Pbc < 0.2%). A comparable 206Pb/238U age (570.0 ± 2.5 Ma, 2σ) was produced by the isotope dilution-thermal ionization mass spectrometry. The secondary ion mass spectrometric and laser ablation-assisted multiple collector inductively coupled plasma mass spectrometer analyses respectively showed that LKZ-1 had little variation in O (δ18OV-SMOW = 10.65 ± 0.14‰; laser fluorination value = 10.72 ± 0.02‰; 1 SD) and Hf (176Hf/177Hf = 0.281794 ± 0.000016, 1 SD) isotopic compositions. LKZ-1 was also fairly homogeneous in its chemical composition (RSD of laser ablation ICPMS data ≤ 10%), displaying a relatively uniform chondrite-normalized rare earth element pattern ((Lu/Gd)N = 31 ± 3, Eu/Eu* = 0.43 ± 0.17, Ce/Ce* = 44 ± 32; 1 SD). These consistencies suggest that the LKZ-1 zircon is a suitable working standard for geochronological and geochemical analyses.
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Gem-Quality Zircon Megacrysts from Placer Deposits in the Central Highlands, Vietnam—Potential Source and Links to Cenozoic Alkali Basalts. MINERALS 2019. [DOI: 10.3390/min9020089] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Gem-quality zircon megacrysts occur in placer deposits in the Central Highlands, Vietnam, and have euhedral to anhedral crystal shapes with dimensions of ~3 cm in length. These zircons have primary inclusions of calcite, olivine, and corundum. Secondary quartz, baddeleyite, hematite, and CO2 fluid inclusions were found in close proximity to cracks and tubular channels. LA-ICP-MS U-Pb ages of analyzed zircon samples yielded two age populations of ca. 1.0 Ma and ca. 6.5 Ma, that were consistent with the ages of alkali basalt eruptions in the Central Highlands at Buon Ma Thuot (5.80–1.67 Ma), Pleiku (4.30–0.80 Ma), and Xuan Loc (0.83–0.44 Ma). The zircon geochemical signatures and primary inclusions suggested a genesis from carbonatite-dominant melts as a result of partial melting of a metasomatized lithospheric mantle source, but not from the host alkali basalt. Chondrite-normalized rare earth element patterns showed a pronounced positive Ce, but negligible Eu anomalies. Detailed hyperspectral Dy3+ photoluminescence images of zircon megacrysts revealed resorption and re-growth processes.
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Secondary magnetite in ancient zircon precludes analysis of a Hadean geodynamo. Proc Natl Acad Sci U S A 2019; 116:407-412. [PMID: 30598434 DOI: 10.1073/pnas.1811074116] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Zircon crystals from the Jack Hills, Western Australia, are one of the few surviving mineralogical records of Earth's first 500 million years and have been proposed to contain a paleomagnetic record of the Hadean geodynamo. A prerequisite for the preservation of Hadean magnetization is the presence of primary magnetic inclusions within pristine igneous zircon. To date no images of the magnetic recorders within ancient zircon have been presented. Here we use high-resolution transmission electron microscopy to demonstrate that all observed inclusions are secondary features formed via two distinct mechanisms. Magnetite is produced via a pipe-diffusion mechanism whereby iron diffuses into radiation-damaged zircon along the cores of dislocations and is precipitated inside nanopores and also during low-temperature recrystallization of radiation-damaged zircon in the presence of an aqueous fluid. Although these magnetites can be recognized as secondary using transmission electron microscopy, they otherwise occur in regions that are indistinguishable from pristine igneous zircon and carry remanent magnetization that postdates the crystallization age by at least several hundred million years. Without microscopic evidence ruling out secondary magnetite, the paleomagnetic case for a Hadean-Eoarchean geodynamo cannot yet been made.
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Diversity in Ruby Geochemistry and Its Inclusions: Intra- and Inter- Continental Comparisons from Myanmar and Eastern Australia. MINERALS 2019. [DOI: 10.3390/min9010028] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Ruby in diverse geological settings leaves petrogenetic clues, in its zoning, inclusions, trace elements and oxygen isotope values. Rock-hosted and isolated crystals are compared from Myanmar, SE Asia, and New South Wales, East Australia. Myanmar ruby typifies metasomatized and metamorphic settings, while East Australian ruby xenocrysts are derived from basalts that tapped underlying fold belts. The respective suites include homogeneous ruby; bi-colored inner (violet blue) and outer (red) zoned ruby; ruby-sapphirine-spinel composites; pink to red grains and multi-zoned crystals of red-pink-white-violet (core to rim). Ruby ages were determined by using U-Pb isotopes in titanite inclusions (Thurein Taung; 32.4 Ma) and zircon inclusions (Mong Hsu; 23.9 Ma) and basalt dating in NSW, >60–40 Ma. Trace element oxide plots suggest marble sources for Thurein Taung and Mong Hsu ruby and ultramafic-mafic sources for Mong Hsu (dark cores). NSW rubies suggest metasomatic (Barrington Tops), ultramafic to mafic (Macquarie River) and metasomatic-magmatic (New England) sources. A previous study showed that Cr/Ga vs. Fe/(V + Ti) plots separate Mong Hsu ruby from other ruby fields, but did not test Mogok ruby. Thurein Taung ruby, tested here, plotted separately to Mong Hsu ruby. A Fe-Ga/Mg diagram splits ruby suites into various fields (Ga/Mg < 3), except for magmatic input into rare Mogok and Australian ruby (Ga/Mg > 6). The diverse results emphasize ruby’s potential for geographic typing.
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17
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PGE-Enrichment in Magnetite-Bearing Olivine Gabbro: New Observations from the Midcontinent Rift-Related Echo Lake Intrusion in Northern Michigan, USA. MINERALS 2018. [DOI: 10.3390/min9010021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The Echo Lake intrusion in the Upper Peninsula (UP) of Michigan, USA, was formed during the 1.1 Ga Midcontinent Rift event in North America. Troctolite is the predominant rock unit in the intrusion, with interlayered bands of peridotite, mafic pegmatitic rock, olivine gabbro, magnetite-bearing gabbro, and anorthosite. Exploratory drilling has revealed a platinum group element (PGE)-enriched zone within a 45 m thick magnetite-ilmenite-bearing olivine gabbro unit with grades up to 1.2 g/t Pt + Pd and 0.3 wt. % Cu. Fine, disseminated grains of sulfide minerals such as pyrrhotite and chalcopyrite occur in the mineralized interval. Formation of Cu-PGE-rich sulfide minerals might have been caused by sulfide melt saturation in a crystallizing magma, which was triggered by a sudden decrease in fO2 upon the crystallization and separation of titaniferous magnetite. This PGE-enriched zone is comparable to other well-known reef-like PGE deposits, such as the Sonju Lake deposit in northern Minnesota.
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18
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Zircon Macrocrysts from the Drybones Bay Kimberlite Pipe (Northwest Territories, Canada): A High-Resolution Trace Element and Geochronological Study. MINERALS 2018. [DOI: 10.3390/min8110481] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Zircon macrocrysts in (sub)volcanic silica-undersaturated rocks are an important source of information about mantle processes and their relative timing with respect to magmatism. The present work describes variations in trace element (Sc, Ti, Y, Nb, lanthanides, Hf, Ta, Pb, Th, and U) and isotopic (U-Pb) composition of zircon from the Drybones Bay kimberlite, Northwest Territories, Canada. These data were acquired at a spatial resolution of ≤100 µm and correlated to the internal characteristics of macrocrysts (imaged using cathodoluminescence, CL). Six types of zircon were distinguished on the basis of its luminescence characteristics, with the majority of grains exhibiting more than one type of CL response. The oscillatory-zoned core and growth sectors of Drybones Bay zircon show consistent variations in rare-earth elements (REE), Hf, Th, and U. Their chondrite-normalized REE patterns are typical of macrocrystic zircon and exhibit extreme enrichment in heavy lanthanides and a positive Ce anomaly. Their Ti content decreases slightly from the core into growth sectors, but the Ti-in-zircon thermometry gives overlapping average crystallization temperatures (820 ± 26 °C to 781 ± 19 °C, respectively). There is no trace element or CL evidence for Pb loss or other forms of chemical re-equilibration. All distinct zircon types are concordant and give a U-Pb age of 445.6 ± 0.8 Ma. We interpret the examined macrocrysts as products of interaction between a shallow (<100 km) mantle source and transient kimberlitic melt.
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Takehara M, Horie K, Hokada T, Kiyokawa S. Data on recovery rates and external morphologies of zircon grains from mechanical and electrical pulverization of rock samples. Data Brief 2018; 19:1537-1544. [PMID: 30229026 PMCID: PMC6141137 DOI: 10.1016/j.dib.2018.06.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 05/11/2018] [Accepted: 06/12/2018] [Indexed: 11/24/2022] Open
Abstract
In this data article, we provide information on the recovery rate and scanning electron microscope (SEM) images of the external morphology of zircon grains separated from two rock samples (AS3 and TEMORA 2) using both mechanical and electrical pulverization systems. The data in this article are related to the research article entitled “New insight into disturbance of U-Pb and trace-element systems in hydrothermally altered zircon via SHRIMP analyses of zircon from the Duluth Gabbro” (Takehara et al., 2018) [1]. Zircons from these two rock samples are widely used as reference materials for U–Pb dating by micro-beam techniques. Rock samples with nearly equal weights were pulverized by both methods, and the recovered zircon grains were then concentrated using conventional mineral-separation methods. Weights of the products at each step in the mineral separation process were measured, and finally the recovery rates of the heavy and non-magnetic minerals, including zircon, were calculated.
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Affiliation(s)
- Mami Takehara
- National Institute of Polar Research, 10-3, Midori-cho, Tachikawa-shi, Tokyo 190-8518, Japan
| | - Kenji Horie
- National Institute of Polar Research, 10-3, Midori-cho, Tachikawa-shi, Tokyo 190-8518, Japan.,Department of Polar Sciences, The Graduate University for Advanced Studies (SOKENDAI), 10-3, Midori-cho, Tachikawa-shi, Tokyo 190-8518, Japan
| | - Tomokazu Hokada
- National Institute of Polar Research, 10-3, Midori-cho, Tachikawa-shi, Tokyo 190-8518, Japan.,Department of Polar Sciences, The Graduate University for Advanced Studies (SOKENDAI), 10-3, Midori-cho, Tachikawa-shi, Tokyo 190-8518, Japan
| | - Shoichi Kiyokawa
- Department of Earth and Planetary Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395 Japan
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Chichester B, Rychert C, Harmon N, van der Lee S, Frederiksen A, Zhang H. Seismic Imaging of the North American Midcontinent Rift Using S-to- P Receiver Functions. JOURNAL OF GEOPHYSICAL RESEARCH. SOLID EARTH 2018; 123:7791-7805. [PMID: 31032165 PMCID: PMC6473666 DOI: 10.1029/2018jb015771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 08/03/2018] [Accepted: 08/17/2018] [Indexed: 06/09/2023]
Abstract
North America's ~1.1-Ga failed Midcontinent Rift (MCR) is a striking feature of gravity and magnetic anomaly maps across the continent. However, how the rift affected the underlying lithosphere is not well understood. With data from the Superior Province Rifting Earthscope Experiment and the USArray Transportable Array, we constrain three-dimensional seismic velocity discontinuity structure in the lithosphere beneath the southwestward arm of the MCR using S-to-P receiver functions. We image a velocity increase with depth associated with the Moho at depths of 33-40 ± 4 km, generally deepening toward the east. The Moho amplitude decreases beneath the rift axis in Minnesota and Wisconsin, where the velocity gradient is more gradual, possibly due to crustal underplating. We see hints of a deeper velocity increase at 61 ± 4-km depth that may be the base of underplating. Beneath the rift axis further south in Iowa, we image two distinct positive phases at 34-39 ± 4 and 62-65 ± 4 km likely related to an altered Moho and an underplated layer. We image velocity decreases with depth at depths of 90-190 ± 7 km in some locations that do not geographically correlate with the rift. These include a discontinuity at depths of 90-120 ± 7 km with a northerly dip in the south that abruptly deepens to 150-190 ± 7 km across the Spirit Lake Tectonic Zone provincial suture. The negative phases may represent a patchy, frozen-in midlithosphere discontinuity feature that likely predates the MCR and/or be related to lithospheric thickness.
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Affiliation(s)
- Ben Chichester
- National Oceanography Centre Southampton, Ocean and Earth SciencesUniversity of SouthamptonSouthamptonUK
| | - Catherine Rychert
- National Oceanography Centre Southampton, Ocean and Earth SciencesUniversity of SouthamptonSouthamptonUK
| | - Nicholas Harmon
- National Oceanography Centre Southampton, Ocean and Earth SciencesUniversity of SouthamptonSouthamptonUK
| | - Suzan van der Lee
- Department of Earth and Planetary SciencesNorthwestern UniversityEvanstonILUSA
| | - Andrew Frederiksen
- Department of Geological SciencesUniversity of ManitobaWinnipegManitobaCanada
| | - Hao Zhang
- Department of Geology and GeophysicsUniversity of UtahSalt Lake CityUTUSA
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21
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Jeong YJ, Lee S, Kim SJ, Jo HJ, Yi K, Cheong ACS. U–Th isotopic microanalysis of zircon reference materials and KBSI working standards. J Anal Sci Technol 2018. [DOI: 10.1186/s40543-018-0148-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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22
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Lukács R, Guillong M, Sliwinski J, Dunkl I, Bachmann O, Harangi S. LA-ICP-MS U-Pb zircon geochronology data of the Early to Mid-Miocene syn-extensional massive silicic volcanism in the Pannonian Basin (East-Central Europe). Data Brief 2018; 19:506-513. [PMID: 29900349 PMCID: PMC5997877 DOI: 10.1016/j.dib.2018.05.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 05/02/2018] [Accepted: 05/04/2018] [Indexed: 11/17/2022] Open
Abstract
This article provides LA-ICP-MS in-situ U-Pb zircon dates performed on single crystals from dacitic to rhyolitic ignimbrites of the Bükkalja Volcanic Field (Hungary, East-Central Europe) temporally covering the main period of the Neogene silicic volcanic activity in the Pannonian Basin. The data include drift-corrected, alpha dose-corrected, Th-disequilibrium-corrected, and filtered data for geochronological use. The data presented in this article are interpreted and discussed in the research article entitled "Early to Mid-Miocene syn-extensional massive silicic volcanism in the Pannonian Basin (East-Central Europe): eruption chronology, correlation potential and geodynamic implications" by Lukács et al. (2018) [1].
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Affiliation(s)
- Réka Lukács
- MTA-ELTE Volcanology Research Group, 1117, Pázmány Péter sétány 1/C, Budapest, Hungary
| | - Marcel Guillong
- Institute of Geochemistry and Petrology, Department of Earth Sciences, ETH Zürich, Clausiusstrasse 25, 8092 Zürich, Switzerland
| | - Jakub Sliwinski
- Institute of Geochemistry and Petrology, Department of Earth Sciences, ETH Zürich, Clausiusstrasse 25, 8092 Zürich, Switzerland
| | - István Dunkl
- Sedimentology & Environmental Geology, Geoscience Center, University of Göttingen, Goldschmidtstrasse 3, D-37077 Göttingen, Germany
| | - Olivier Bachmann
- Institute of Geochemistry and Petrology, Department of Earth Sciences, ETH Zürich, Clausiusstrasse 25, 8092 Zürich, Switzerland
| | - Szabolcs Harangi
- MTA-ELTE Volcanology Research Group, 1117, Pázmány Péter sétány 1/C, Budapest, Hungary
- Department of Petrology and Geochemistry, Eötvös Loránd University, 1117, Budapest Pázmány Péter sétány 1/C, Budapest, Hungary
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LA-ICP-MS and SIMS U-Pb and U-Th zircon geochronological data of Late Pleistocene lava domes of the Ciomadul Volcanic Dome Complex (Eastern Carpathians). Data Brief 2018; 18:808-813. [PMID: 29900242 PMCID: PMC5996732 DOI: 10.1016/j.dib.2018.03.100] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 03/20/2018] [Accepted: 03/21/2018] [Indexed: 11/23/2022] Open
Abstract
This article provides laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and secondary ionization mass spectrometry (SIMS) U-Pb and U-Th zircon dates for crystals separated from Late Pleistocene dacitic lava dome rocks of the Ciomadul Volcanic Dome Complex (Eastern Carpathians, Romania). The analyses were performed on unpolished zircon prism faces (termed rim analyses) and on crystal interiors exposed through mechanical grinding an polishing (interior analyses). 206Pb/238U ages are corrected for Th-disequilibrium based on published and calculated distribution coefficients for U and Th using average whole-rock and individually analyzed zircon compositions. The data presented in this article were used for the Th-disequilibrium correction of (U-Th)/He zircon geochronology data in the research article entitled “The onset of the volcanism in the Ciomadul Volcanic Dome Complex (Eastern Carpathians): eruption chronology and magma type variation” (Molnár et al., 2018) [1].
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Mucek AE, Danišík M, de Silva SL, Schmitt AK, Pratomo I, Coble MA. Post-supereruption recovery at Toba Caldera. Nat Commun 2017; 8:15248. [PMID: 28508876 PMCID: PMC5440807 DOI: 10.1038/ncomms15248] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Accepted: 03/13/2017] [Indexed: 11/25/2022] Open
Abstract
Large calderas, or supervolcanoes, are sites of the most catastrophic and hazardous events on Earth, yet the temporal details of post-supereruption activity, or resurgence, remain largely unknown, limiting our ability to understand how supervolcanoes work and address their hazards. Toba Caldera, Indonesia, caused the greatest volcanic catastrophe of the last 100 kyr, climactically erupting ∼74 ka. Since the supereruption, Toba has been in a state of resurgence but its magmatic and uplift history has remained unclear. Here we reveal that new 14C, zircon U–Th crystallization and (U–Th)/He ages show resurgence commenced at 69.7±4.5 ka and continued until at least ∼2.7 ka, progressing westward across the caldera, as reflected by post-caldera effusive lava eruptions and uplifted lake sediment. The major stratovolcano north of Toba, Sinabung, shows strong geochemical kinship with Toba, and zircons from recent eruption products suggest Toba's climactic magma reservoir extends beneath Sinabung and is being tapped during eruptions. Toba Caldera in Indonesia had one of the largest volcanic eruptions over the last 100 kyr and has since undergone periods of resurgence. Here, the authors present zircon and sediment age data showing resurgence started after the climactic eruption and lasted until 2.7 ka, advancing west and south.
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Affiliation(s)
- Adonara E Mucek
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, 104 CEOAS Administration Building, Corvallis, OR 97331-5503, USA
| | - Martin Danišík
- John de Laeter Centre, Building 301, Curtin University, Bentley, Western Australia 6845, Australia
| | - Shanaka L de Silva
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, 104 CEOAS Administration Building, Corvallis, OR 97331-5503, USA
| | - Axel K Schmitt
- Institute of Earth Sciences, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 236, Heidelberg D-69120, Germany
| | - Indyo Pratomo
- Geological Agency of Indonesia, JL. Diponegoro No. 57, Jawa Barat, Indonesia
| | - Matthew A Coble
- SHRIMP-RG Lab, Green Earth Sciences Building, 367 Panama Street Room 89, Stanford University, California 94305, USA
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Abstract
Felsic magmatic systems represent the vast majority of volcanic activity that poses a threat to human life. The tempo and magnitude of these eruptions depends on the physical conditions under which magmas are retained within the crust. Recently the case has been made that volcanic reservoirs are rarely molten and only capable of eruption for durations as brief as 1,000 years following magma recharge. If the "cold storage" model is generally applicable, then geophysical detection of melt beneath volcanoes is likely a sign of imminent eruption. However, some arc volcanic centers have been active for tens of thousands of years and show evidence for the continual presence of melt. To address this seeming paradox, zircon geochronology and geochemistry from both the frozen lava and the cogenetic enclaves they host from the Soufrière Volcanic Center (SVC), a long-lived volcanic complex in the Lesser Antilles arc, were integrated to track the preeruptive thermal and chemical history of the magma reservoir. Our results show that the SVC reservoir was likely eruptible for periods of several tens of thousands of years or more with punctuated eruptions during these periods. These conclusions are consistent with results from other arc volcanic reservoirs and suggest that arc magmas are generally stored warm. Thus, the presence of intracrustal melt alone is insufficient as an indicator of imminent eruption, but instead represents the normal state of magma storage underneath dormant volcanoes.
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Alleon J, Bernard S, Le Guillou C, Marin-Carbonne J, Pont S, Beyssac O, McKeegan KD, Robert F. Molecular preservation of 1.88 Ga Gunflint organic microfossils as a function of temperature and mineralogy. Nat Commun 2016; 7:11977. [PMID: 27312070 PMCID: PMC4915024 DOI: 10.1038/ncomms11977] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 05/18/2016] [Indexed: 01/06/2023] Open
Abstract
The significant degradation that fossilized biomolecules may experience during burial makes it challenging to assess the biogenicity of organic microstructures in ancient rocks. Here we investigate the molecular signatures of 1.88 Ga Gunflint organic microfossils as a function of their diagenetic history. Synchrotron-based XANES data collected in situ on individual microfossils, at the submicrometre scale, are compared with data collected on modern microorganisms. Despite diagenetic temperatures of ∼150–170 °C deduced from Raman data, the molecular signatures of some Gunflint organic microfossils have been exceptionally well preserved. Remarkably, amide groups derived from protein compounds can still be detected. We also demonstrate that an additional increase of diagenetic temperature of only 50 °C and the nanoscale association with carbonate minerals have significantly altered the molecular signatures of Gunflint organic microfossils from other localities. Altogether, the present study provides key insights for eventually decoding the earliest fossil record. Thermal diagenesis is generally seen as detrimental to the preservation of organic biosignatures. Using synchrotron-based XANES data, Alleon et al. find preservation of the molecular signatures of organic microfossils from the 1.88 Ga Gunflint cherts.
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Affiliation(s)
- Julien Alleon
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Sorbonne Universités - CNRS UMR 7590, Muséum National d'Histoire Naturelle, UPMC Univ Paris 06, IRD UMR 206, 61 rue Buffon, 75005 Paris, France
| | - Sylvain Bernard
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Sorbonne Universités - CNRS UMR 7590, Muséum National d'Histoire Naturelle, UPMC Univ Paris 06, IRD UMR 206, 61 rue Buffon, 75005 Paris, France
| | - Corentin Le Guillou
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Sorbonne Universités - CNRS UMR 7590, Muséum National d'Histoire Naturelle, UPMC Univ Paris 06, IRD UMR 206, 61 rue Buffon, 75005 Paris, France
| | - Johanna Marin-Carbonne
- Univ Lyon, UJM Saint Etienne, Laboratoire Magma et Volcans, UBP, CNRS, IRD, 23 rue Dr Paul Michelon, 42100 St Etienne, France
| | - Sylvain Pont
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Sorbonne Universités - CNRS UMR 7590, Muséum National d'Histoire Naturelle, UPMC Univ Paris 06, IRD UMR 206, 61 rue Buffon, 75005 Paris, France
| | - Olivier Beyssac
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Sorbonne Universités - CNRS UMR 7590, Muséum National d'Histoire Naturelle, UPMC Univ Paris 06, IRD UMR 206, 61 rue Buffon, 75005 Paris, France
| | - Kevin D McKeegan
- Department of Earth, Planetary and Space Sciences, University of California-Los Angeles, 595 Charles Young Drive East, Los Angeles, California 90095-1567, USA
| | - François Robert
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Sorbonne Universités - CNRS UMR 7590, Muséum National d'Histoire Naturelle, UPMC Univ Paris 06, IRD UMR 206, 61 rue Buffon, 75005 Paris, France
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Anderson FS, Levine J, Whitaker TJ. Rb-Sr resonance ionization geochronology of the Duluth Gabbro: A proof of concept for in situ dating on the Moon. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2015; 29:1457-1464. [PMID: 26212160 PMCID: PMC5008139 DOI: 10.1002/rcm.7253] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 06/11/2015] [Accepted: 06/12/2015] [Indexed: 05/31/2023]
Abstract
RATIONALE We report new (87) Rb-(87) Sr isochron data for the Duluth Gabbro, obtained with a laser ablation resonance ionization mass spectrometer that is a prototype spaceflight instrument. The gabbro has a Rb abundance and a range of Rb/Sr ratios that are similar to those of KREEP-rich basalts found on the nearside of the Moon. Dating of previously un-sampled young lunar basalts, which generally have a KREEP-rich composition, is critical for understanding the bombardment history of the Moon since 3.5 Ga, which in turn informs the chronology of the solar system. Measurements of lunar analogs like the Duluth Gabbro are a proof of concept for in situ dating of rocks on the Moon to constrain lunar history. METHODS Using the laser ablation resonance ionization mass spectrometer we ablated hundreds of locations on a sample, and at each one measured the relative abundances of the isotopes of Rb and Sr. A delay between the resonant photoionization processes separates the elements in time, eliminating the potential interference between (87) Rb and (87) Sr. This enables the determination of (87) Rb-(87) Sr isochron ages without sophisticated sample preparation that would be impractical in a spaceflight context. RESULTS We successfully dated the Duluth Gabbro to 800 ± 300 Ma using traditional isochron methods like those used in our earlier analysis of the Martian meteorite Zagami. However, we were able to improve this to 1100 ± 200 Ma, an accuracy of <1σ, using a novel normalization approach. Both these results agree with the age determined by Faure et al. in 1969, but our novel normalization improves our precision. CONCLUSIONS Demonstrating that this technique can be used for measurements at this level of difficulty makes ~32% of the lunar nearside amenable to in situ dating, which can complement or supplement a sample return program. Given these results and the scientific value of dating young lunar basalts, we have recently proposed a spaceflight mission called the Moon Age and Regolith Explorer (MARE).
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Affiliation(s)
- F Scott Anderson
- Southwest Research Institute, Suite 300, 1050 Walnut St, Boulder, CO, 80302, USA
| | - Jonathan Levine
- Department of Physics and Astronomy, Colgate University, Hamilton, NY, 13346, USA
| | - Tom J Whitaker
- Southwest Research Institute, Suite 300, 1050 Walnut St, Boulder, CO, 80302, USA
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Qinghu zircon: A working reference for microbeam analysis of U-Pb age and Hf and O isotopes. ACTA ACUST UNITED AC 2013. [DOI: 10.1007/s11434-013-5932-x] [Citation(s) in RCA: 421] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Provenance of Late Paleozoic-Mesozoic Sandstones, Taimyr Peninsula, the Arctic. GEOSCIENCES 2013. [DOI: 10.3390/geosciences3030502] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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A search for thermal excursions from ancient extraterrestrial impacts using Hadean zircon Ti-U-Th-Pb depth profiles. Proc Natl Acad Sci U S A 2012; 109:13486-92. [PMID: 22869711 DOI: 10.1073/pnas.1208006109] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Few terrestrial localities preserve more than a trace lithic record prior to ca. 3.8 Ga greatly limiting our understanding of the first 700 Ma of Earth history, a period inferred to have included a spike in the bolide flux to the inner solar system at ca. 3.85-3.95 Ga (the Late Heavy Bombardment, LHB). An accessible record of this era may be found in Hadean detrital zircons from the Jack Hills, Western Australia, in the form of μm-scale epitaxial overgrowths. By comparing crystallization temperatures of pre-3.8 Ga zircon overgrowths to the archive of zircon temperature spectra, it should, in principle, be possible to identify a distinctive impact signature. We have developed Ti-U-Th-Pb ion microprobe depth profiling to obtain age and temperature information within these zircon overgrowths and undertaken a feasibility study of its possible use in identifying impact events. Of eight grains profiled in this fashion, four have overgrowths of LHB-era age. Age vs. temperature profiles reveal a period between ca. 3.85-3.95 Ga (i.e., LHB era) characterized by significantly higher temperatures (approximately 840-875 °C) than do older or younger zircons or zircon domains (approximately 630-750 °C). However, temperatures approaching 900 °C can result in Pb isotopic exchange rendering interpretation of these profiles nonunique. Coupled age-temperature depth profiling shows promise in this role, and the preliminary data we report could represent the first terrestrial evidence for impact-related heating during the LHB.
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Bühn B, Pimentel MM, Matteini M, Dantas EL. High spatial resolution analysis of Pb and U isotopes for geochronology by laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS). AN ACAD BRAS CIENC 2009. [DOI: 10.1590/s0001-37652009000100011] [Citation(s) in RCA: 167] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Age determinations using the 235U and 238U radioactive decay series to the daughter isotopes 207Pb and 206Pb, respectively, using the mineral zircon (ZrSiO4), are widely used to decipher geological processes. A new method developed in the last couple of years, the laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS), overcomes previous laborious sample preparation, and yields isotopic ratios and age data with a high spatial resolution of ten of microns. The present study describes the analytical set-up and data reduction process as presently applied at the Laboratory for Geochronology of the University of Brasília. It explores the precision and accuracy of the method by cross-analysing three international zircon standards. We arrive at a precision of 1.9 to 3.7% (2σ SD) and an accuracy of 0.6 to 3.8% (2σ SD) for and U isotopic ratios of the standards. We also apply the method to two natural zircon samples, which have previously been dated by other analytical methods. A comparison of the results show a good conformity of the age data,being whitin the error limits. The data demonstrate the great analytical potential of the method for rapid, precise and accurate U-Pb isotopic analyses on the micron scale.
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Morton AC, Herries R, Fanning M. Chapter 41 Correlation of Triassic Sandstones in the Strathmore Field, West of Shetland, Using Heavy Mineral Provenance Signatures. DEVELOPMENTS IN SEDIMENTOLOGY 2007. [DOI: 10.1016/s0070-4571(07)58041-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Kapp JLD. Nyainqentanglha Shan: A window into the tectonic, thermal, and geochemical evolution of the Lhasa block, southern Tibet. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2004jb003330] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Cowgill E, Yin A, Harrison TM, Xiao-Feng W. Reconstruction of the Altyn Tagh fault based on U-Pb geochronology: Role of back thrusts, mantle sutures, and heterogeneous crustal strength in forming the Tibetan Plateau. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2002jb002080] [Citation(s) in RCA: 230] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Eric Cowgill
- Department of Earth and Space Sciences and Institute of Geophysics and Planetary Physics; University of California; Los Angeles California USA
| | - An Yin
- Department of Earth and Space Sciences and Institute of Geophysics and Planetary Physics; University of California; Los Angeles California USA
| | - T. Mark Harrison
- Department of Earth and Space Sciences and Institute of Geophysics and Planetary Physics; University of California; Los Angeles California USA
| | - Wang Xiao-Feng
- Institute of Geomechanics; Chinese Academy of Geological Sciences; Beijing China
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PIMENTEL MÁRCIOM, DANTAS ELTONL, FUCK REINHARDTA, ARMSTRONG RICHARDA. Shrimp and conventional U-Pb age, Sm-Nd isotopic characteristics and tectonic significance of the K-rich Itapuranga suite in Goiás, Central Brazil. AN ACAD BRAS CIENC 2003. [DOI: 10.1590/s0001-37652003000100011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The Itapuranga alkali granite and Uruana quartz syenite are large K-rich EW-elongated intrusions, in the central part of the Neoproterozoic Brasília Belt, central Brazil. They are associated with Pireneus lineaments, which cut the regional NNW-SSE structures of the southern part of the belt. SHRIMP and conventional U-Pb data for the Itapuranga and Uruana intrusions indicate crystallization ages of 624 ± 10 Ma and 618 ± 4 Ma, respectively. Three zircon cores from the Itapuranga granite yielded U-Pb ages between 1.79 and 1.49 Ga. Sm-Nd T DM ages for both intrusions are 1.44 Ga and epsilonNd(T) values are -5.1 and -5.7, suggesting the input of material derived from older (Paleo- to Mesoproterozoic) sialic crust in the origin of the parental magmas. Magma mixing structures indicate co-existence of mafic and felsic end-members. The felsic end-member of the intrusions is dominantly represented by crust-derived melts, formed in response to the invasion of Paleo/Mesoproterozoic sialic crust by alkali-rich mafic magmas at ca. 620 Ma. These intrusions are roughly contemporaneous with, or perhaps slightly younger than, the peak of regional metamorphism in the southern Brasília Belt. Their emplacement along the Pireneus lineament suggest a syn-tectonic origin for them, most probably in transtensional settings along these faults.
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Mojzsis SJ, Harrison TM, Pidgeon RT. Oxygen-isotope evidence from ancient zircons for liquid water at the Earth's surface 4,300 Myr ago. Nature 2001; 409:178-81. [PMID: 11196638 DOI: 10.1038/35051557] [Citation(s) in RCA: 146] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Granitoid gneisses and supracrustal rocks that are 3,800-4,000 Myr old are the oldest recognized exposures of continental crust. To obtain insight into conditions at the Earth's surface more than 4 Gyr ago requires the analysis of yet older rocks or their mineral remnants. Such an opportunity is presented by detrital zircons more than 4 Gyr old found within 3-Gyr-old quartzitic rocks in the Murchison District of Western Australia. Here we report in situ U-Pb and oxygen isotope results for such zircons that place constraints on the age and composition of their sources and may therefore provide information about the nature of the Earth's early surface. We find that 3,910-4,280 Myr old zircons have oxygen isotope (delta18O) values ranging from 5.4+/-0.6% to 15.0+/-0.4%. On the basis of these results, we postulate that the approximately 4,300-Myr-old zircons formed from magmas containing a significant component of re-worked continental crust that formed in the presence of water near the Earth's surface. These data are therefore consistent with the presence of a hydrosphere interacting with the crust by 4,300 Myr ago.
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Affiliation(s)
- S J Mojzsis
- Department of Earth and Space Sciences and IGPP Center for Astrobiology, University of California Los Angeles, 90095-1567, USA.
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Harrison TM, Yin A, Grove M, Lovera OM, Ryerson FJ, Zhou X. The Zedong Window: A record of superposed Tertiary convergence in southeastern Tibet. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/2000jb900078] [Citation(s) in RCA: 170] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Quidelleur X, Grove M, Lovera OM, Harrison TM, Yin A, Ryerson FJ. Thermal evolution and slip history of the Renbu Zedong Thrust, southeastern Tibet. ACTA ACUST UNITED AC 1997. [DOI: 10.1029/96jb02483] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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