Electron probe (Ultrachron) microchronometry of metamorphic monazite: Unraveling the timing of polyphase thermotectonism in the easternmost Wyoming Craton (Black Hills, South Dakota)
-
Peter S. Dahl
,
Michael P. Terry
Abstract
A metapelite from the easternmost Wyoming craton (Black Hills, South Dakota) has been analyzed by microstructural methods to unravel polyphase deformational history associated with 1800.1700 Ma assembly of southern Laurentia. Three deformational fabrics are recognized in oriented thin sections: an ENE-trending S1 fabric, preserved as oblique inclusion trails in garnet porphyroblasts; a NNWtrending S2 fabric, preserved as microlithons in the rock matrix; and a flattening fabric, S3, which transposed S1-S2 and dominates the matrix. A complex monazite porphyroblast has been analyzed in situ with the electron microprobe (Ultrachron) to constrain the timing of S1-S3 fabric formation associated with monazite growth. The core of this grain uniquely preserves the S1-S2 fabrics as sigmoidal inclusion trails. The mean total-Pb age of this domain is 1750 ± 10 Ma (all dates reported at 95% confidence; n = 39 spots), which is equivalent to the published 207Pb/206Pb age for the same domain. These results validate the total-Pb dating method in general and the Ultrachron in particular, for reliable age determination in low-Th monazite, and are interpreted as 1750 Ma minimum ages for the S1-S2 fabrics and sequential, D1-D2 collisional events that imposed them (~N-directed arc accretion and ~E-W continental collision, respectively). A higher-Th,Y rim of this same .Rosetta. grain truncates the S1-S2 sigmoid, and is associated with resorption textures in garnet porphyroblasts, coupled release of Y, and an S3 fabric that pervasively overprinted S1-S2 in the rock matrix. The mean Ultrachron date of this domain is 1692 ± 5 Ma (n = 17 spots), which is slightly younger that the published isotopic age for all monazite rims combined. These results support a ~1715.1690 Ma timeframe for localized doming (D3) related to granite magmatism, the onset of which has been dated independently at 1715 ± 3 Ma. The timing of post-D3 cooling through 350 and 300 °C is constrained by 40Ar/39Ar dates of ~1610 and ~1480 Ma obtained for separates of D3 matrix muscovite and biotite, respectively, which are interpreted as closure ages.
This study shows that fabrics in poly-deformed rocks can be dated by linking monazite spot ages to key microtextures. Further, the results of this micrometer-scale study enhance previous knowledge of local thermotectonism (Black Hills) and regional terrane assembly (Laurentia).
© 2015 by Walter de Gruyter Berlin/Boston
Articles in the same Issue
- Electronic article. Getting the inside story: using computed X-ray tomography to study inclusion trails in garnet porphyroblasts
- Structure of framboidal pyrite: An electron backscatter diffraction study
- The mineralogical microstructure of shells: PART 2.1 The iridescence colors of abalone shells
- Electron probe (Ultrachron) microchronometry of metamorphic monazite: Unraveling the timing of polyphase thermotectonism in the easternmost Wyoming Craton (Black Hills, South Dakota)
- New mineral occurrences and mineralization processes: Wuda coal-fire gas vents of Inner Mongolia
- Synchrotron micro-X-ray fluorescence analysis of natural diamonds: First steps in identification of mineral inclusions in situ
- Speciation and distribution of sulfur in a mollusk shell as revealed by in situ maps using X-ray absorption near-edge structure (XANES) spectroscopy at the S K-edge
- Experimental study on diamond dissolution in kimberlitic and lamproitic melts at 1300-1420 °C and 1 GPa with controlled oxygen partial pressure
- Validation of LA-ICP-MS fluid inclusion analysis with synthetic fluid inclusions
- Etch pit coalescence, surface area, and overall mineral dissolution rates
- Crystal chemistry of the elbaite-schorl series
- Morphology of nanomagnetite crystals: Implications for formation conditions
- Fragmentation phenomena in populations of magmatic crystals
- Kinetics of Fe2+-Mg order-disorder in P21/c pigeonite
- First-principles studies on the elastic constants of a 1:1 layered kaolinite mineral
- Quantum mechanical calculations of trans-vacant and cis-vacant polymorphism in dioctahedral 2:1 phyllosilicates
- The stability and Raman spectra of ikaite, CaCO3·6H2O, at high pressure and temperature
- Model pyroxenes III: Volume of C2/c pyroxenes at mantle P, T, and x
- The kinetics and mechanisms of goethite and hematite crystallization under alkaline conditions, and in the presence of phosphate
- High-resolution 17O MAS NMR spectroscopy of forsterite (α-Mg2SiO4), wadsleyite (β-Mg2SiO4), and ringwoodite (γ-Mg2SiO4)
- Comparative study of equilibrated and unequilibrated eucrites: Subsolidus thermal histories of Haraiya and Pasamonte
- Origin and internal evolution of the Li-F-Be-B-P-bearing Pinilla de Fermoselle pegmatite (Central Iberian Zone, Zamora, Spain)
- Single-crystal X-ray diffraction of spinels from the San Carlos Volcanic Field, Arizona: Spinel as a geothermometer
- Letter. Direct observations of pseudomorphism: compositional and textural evolution at a fluid- solid interface
- Letter. Carbon oxides in cordierite channels: Determination of CO2 isotopic species and CO by single crystal IR spectroscopy
- Comment on Melluso et al. (2003) Reported data and interpretation of some wollastonite- and melilite-bearing rocks from the Central Apennines of Italy
- Reply to stoppa et.al. 2005. Wollastonite- anorthite- gehlenite-, and fassaite-bearing rocks: Igneous petrological oddity or paralavas?
- Comment on Melluso et.al. (2003). The Ricetto and Colle Fabbri wollastonite and melilite-bearing rocks of the central Apennines, Italy
- Reply to Capitanio 2005. Mineralogic and bulk rock composition of Italian wollastonite- and melilite-bearing paralava and clinker: Further evidence of their pyrometamorphic nature
Articles in the same Issue
- Electronic article. Getting the inside story: using computed X-ray tomography to study inclusion trails in garnet porphyroblasts
- Structure of framboidal pyrite: An electron backscatter diffraction study
- The mineralogical microstructure of shells: PART 2.1 The iridescence colors of abalone shells
- Electron probe (Ultrachron) microchronometry of metamorphic monazite: Unraveling the timing of polyphase thermotectonism in the easternmost Wyoming Craton (Black Hills, South Dakota)
- New mineral occurrences and mineralization processes: Wuda coal-fire gas vents of Inner Mongolia
- Synchrotron micro-X-ray fluorescence analysis of natural diamonds: First steps in identification of mineral inclusions in situ
- Speciation and distribution of sulfur in a mollusk shell as revealed by in situ maps using X-ray absorption near-edge structure (XANES) spectroscopy at the S K-edge
- Experimental study on diamond dissolution in kimberlitic and lamproitic melts at 1300-1420 °C and 1 GPa with controlled oxygen partial pressure
- Validation of LA-ICP-MS fluid inclusion analysis with synthetic fluid inclusions
- Etch pit coalescence, surface area, and overall mineral dissolution rates
- Crystal chemistry of the elbaite-schorl series
- Morphology of nanomagnetite crystals: Implications for formation conditions
- Fragmentation phenomena in populations of magmatic crystals
- Kinetics of Fe2+-Mg order-disorder in P21/c pigeonite
- First-principles studies on the elastic constants of a 1:1 layered kaolinite mineral
- Quantum mechanical calculations of trans-vacant and cis-vacant polymorphism in dioctahedral 2:1 phyllosilicates
- The stability and Raman spectra of ikaite, CaCO3·6H2O, at high pressure and temperature
- Model pyroxenes III: Volume of C2/c pyroxenes at mantle P, T, and x
- The kinetics and mechanisms of goethite and hematite crystallization under alkaline conditions, and in the presence of phosphate
- High-resolution 17O MAS NMR spectroscopy of forsterite (α-Mg2SiO4), wadsleyite (β-Mg2SiO4), and ringwoodite (γ-Mg2SiO4)
- Comparative study of equilibrated and unequilibrated eucrites: Subsolidus thermal histories of Haraiya and Pasamonte
- Origin and internal evolution of the Li-F-Be-B-P-bearing Pinilla de Fermoselle pegmatite (Central Iberian Zone, Zamora, Spain)
- Single-crystal X-ray diffraction of spinels from the San Carlos Volcanic Field, Arizona: Spinel as a geothermometer
- Letter. Direct observations of pseudomorphism: compositional and textural evolution at a fluid- solid interface
- Letter. Carbon oxides in cordierite channels: Determination of CO2 isotopic species and CO by single crystal IR spectroscopy
- Comment on Melluso et al. (2003) Reported data and interpretation of some wollastonite- and melilite-bearing rocks from the Central Apennines of Italy
- Reply to stoppa et.al. 2005. Wollastonite- anorthite- gehlenite-, and fassaite-bearing rocks: Igneous petrological oddity or paralavas?
- Comment on Melluso et.al. (2003). The Ricetto and Colle Fabbri wollastonite and melilite-bearing rocks of the central Apennines, Italy
- Reply to Capitanio 2005. Mineralogic and bulk rock composition of Italian wollastonite- and melilite-bearing paralava and clinker: Further evidence of their pyrometamorphic nature
