Versatile Monazite: resolving geological records and solving challenges in materials science: Generalizations about monazite: Implications for geochronologic studies

Catlos, Elizabeth J.

doi:10.2138/am.2013.4336

Cited by 67 publications

(25 citation statements)

References 163 publications

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“…Rather, it is possible that the progressive growth and recrystallization of monazite, and therefore the internal compositional variation, and the large span of ages recorded within both individual grains and overall, is also influenced strongly by microstructural location. Specifically, monazite growth in these rocks may also be controlled by proximity to garnet porphyroblasts and the presence and crystallisation of REE-Th-Y-bearing melt (Catlos, 2013;Hinchey et al, 2007;Kelly et al, 2006Kelly et al, , 2012Reno et al, 2012).…”

Section: Duration Of High-temperature Conditionsmentioning

confidence: 99%

A duality of timescales: Short-lived ultrahigh temperature metamorphism preserving a long-lived monazite growth history in the Grenvillian Musgrave–Albany–Fraser Orogen

Tucker

Hand

Kelsey

et al. 2015

Precambrian Research

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Section: Duration Of High-temperature Conditionsmentioning

confidence: 99%

A duality of timescales: Short-lived ultrahigh temperature metamorphism preserving a long-lived monazite growth history in the Grenvillian Musgrave–Albany–Fraser Orogen

Tucker

Hand

Kelsey

et al. 2015

Precambrian Research

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“…The possibility we sampled a region that differs from our interpretations (altered vs. least-altered, tables 5 and 6) is remote because we imaged the grain surface before and after analyses. Correlations between monazite age and composition do not always exist (Hokada and Motoyoshi, 2006;Hinchey and others, 2007;Martin and others, 2007;Triantafyllidis and others, 2010;Reno and others, 2012; see review in Catlos, 2013), and our visual observations are mainly restricted to monazite appearance using BSE only. Regions with darker BSE contrast occur within and in close proximity to microcrack networks and appear to crosscut zones of interpreted primary sector growth (figs.…”

Section: Amelia Monazite Ages: Tectonic Interpretationmentioning

confidence: 78%

Ion microprobe ²³²Th-²⁰⁸Pb ages from high common Pb monazite, Morefield Mine, Amelia County, Virginia: Implications for Alleghanian tectonics

Catlos

Miller

2016

Am J Sci

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Monazite [(Ce,Th)PO 4 ] from a pegmatite in the Morefield Mine of the eastern Piedmont of central Virginia has unusually high and variable amounts of common Pb, leading to problematic interpretations of its U-Th-Pb ages and how the monazite relates to nearby granite intrusions and faults. To address these issues, we analyze a single large monazite grain from the pegmatite using electron microprobe analysis (EMPA, n ‫؍‬ 64), laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS, n ‫؍‬ 58), and secondary ion mass spectrometry (SIMS, n ‫؍‬ 59). The monazite study grain exhibits compositional variations in proximity to microcracks consistent regions of secondary alteration and recrystallization. Although the compositions of these regions fit the ideal stoichiometry of monazite, they have lower Si, Th, U, and Y, and higher P, rare earth element (REE), and Ca concentrations compared to visibly unaltered portions of the grain. LA-ICP-MS and SIMS analyses demonstrate that common Pb, as proxied by 204 Pb, is enriched in proximity to microcrack regions and correlates with 137 Ba. SIMS 232 Th-208 Pb analysis from grain regions with lowest contents of common Pb ( 208 Pb comprises >99% of Pb isotopes) yields two sets of ages: 263.5؎3.0 Ma (؎1; MSWD ‫؍‬ 1.7; n ‫؍‬ 11) and 234.1؎3.3 Ma (؎1; MSWD ‫؍‬ 0.4; n ‫؍‬ 13). Regionally, the ages are similar to the youngest Appalachian pegmatite bodies emplaced during the terminal (Alleghanian) Laurentia-Africa collision. However, the monazite ages are younger than locally surrounding intrusions. The closest intrusive in distance (ϳ30 km) and age is the Petersburg granite (296.33؎0.11 Ma, zircon 238 U-206 Pb), the emplacement of which coincided with activity along the Hylas Fault. Because the fault experienced a brittle-ductile transition in the Late Permian (ϳ262 Ma), coeval with the older 232 Th-208 Pb monazite age group, we postulate that the Hylas Fault may have operated as a fluid migration system between the Petersburg granite and Morefield Mine pegmatite. The younger monazite age coincides with Triassic normal and/or sinistral faulting linked to the development and deformation of local rift basins.

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“…This was followed in the eastern Lepontine Dome and along the Insubric Line between 22 and 17 Ma by a period of rapid cooling (Steck and Hunziker, 1994;Rubatto et al, 2009), after which exhumation slowed down. The area to the west in the surroundings of the Rhone-Simplon Line experienced phases of accelerated cooling somewhat later at 18-15 and 12-10 Ma (Campani et al, 2014).…”

Section: Evolution Of the Study Areamentioning

confidence: 99%

Dating tectonic activity in the Lepontine Dome and Rhone-Simplon Fault regions through hydrothermal monazite-(Ce)

et al. 2020

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Abstract. Zoned hydrothermal monazite-(Ce) from Alpine-type fissures and clefts is used to gain new insights into the tectonic history of the Lepontine Dome in the Central Alps and the timing of deformation along the Rhone-Simplon Fault zone on the dome's western end. Hydrothermal monazites-(Ce) (re)crystallization ages directly date deformation that induces changes in physicochemical conditions of the fissure or cleft fluid. A total of 480 secondary ion mass spectrometry (SIMS) spot analyses from 20 individual crystals, including co-type material of the monazite-(Nd) type locality, record ages for the time of ∼19 to 2.7 Ma, with individual grains recording age ranges of 2 to 7.5 Myr. The combination of these age data with geometric considerations and spatial distribution across the Lepontine region gives a more precise young exhumation history for the area. At the northeastern and southwestern edges of the Lepontine Dome, units underwent hydrothermal monazite-(Ce) growth at 19–12.5 and 16.5–10.5 Ma, respectively, while crystallization of monazite-(Ce) in the eastern Lepontine Dome started later, at 15–10 Ma. Fissure monazite-(Ce) along the western limit of the dome reports younger ages of 13–7 Ma. A younger age group around 8–5 Ma is limited to fissures and clefts associated with the Simplon normal fault and related strike-slip faults such as the Rhone Fault. The data set shows that the monazite-(Ce) age record directly links the fluid-induced interaction between fissure mineral and host rock to the Lepontine Dome's evolution in space and time. A comparison between hydrothermal monazite-(Ce) and thermochronometric data suggest that hydrothermal monazite-(Ce) dating may allow us to identify areas of slow exhumation or cooling rates during ongoing tectonic activity.

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Versatile Monazite: resolving geological records and solving challenges in materials science: Generalizations about monazite: Implications for geochronologic studies

Cited by 67 publications

References 163 publications

A duality of timescales: Short-lived ultrahigh temperature metamorphism preserving a long-lived monazite growth history in the Grenvillian Musgrave–Albany–Fraser Orogen

A duality of timescales: Short-lived ultrahigh temperature metamorphism preserving a long-lived monazite growth history in the Grenvillian Musgrave–Albany–Fraser Orogen

Ion microprobe ²³²Th-²⁰⁸Pb ages from high common Pb monazite, Morefield Mine, Amelia County, Virginia: Implications for Alleghanian tectonics

Dating tectonic activity in the Lepontine Dome and Rhone-Simplon Fault regions through hydrothermal monazite-(Ce)

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Versatile Monazite: resolving geological records and solving challenges in materials science: Generalizations about monazite: Implications for geochronologic studies

Cited by 67 publications

References 163 publications

A duality of timescales: Short-lived ultrahigh temperature metamorphism preserving a long-lived monazite growth history in the Grenvillian Musgrave–Albany–Fraser Orogen

A duality of timescales: Short-lived ultrahigh temperature metamorphism preserving a long-lived monazite growth history in the Grenvillian Musgrave–Albany–Fraser Orogen

Ion microprobe 232Th-208Pb ages from high common Pb monazite, Morefield Mine, Amelia County, Virginia: Implications for Alleghanian tectonics

Dating tectonic activity in the Lepontine Dome and Rhone-Simplon Fault regions through hydrothermal monazite-(Ce)

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Ion microprobe ²³²Th-²⁰⁸Pb ages from high common Pb monazite, Morefield Mine, Amelia County, Virginia: Implications for Alleghanian tectonics