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Rasmus Andreasen

Variable Tl, Pb, and Cd concentrations and isotope compositions of enstatite and ordinary chondrites—Evidence for volatile element mobilization and decay of extinct205Pb

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Variable Tl, Pb, and Cd concentrations and isotope compositions of enstatite and ordinary chondrites—Evidence for volatile element mobilization and decay of extinct205Pb. / Palk, Emiliana Maria; Andreasen, Rasmus; Rehkämper, Mark ; Stunt, Alison; Kreissig, Katharina; Coles, Barry; Schönbächler, Maria; Smith, Caroline.

I: Meteoritics and Planetary Science, Bind 53, Nr. 2, 02.2018, s. 167-186.

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avisTidsskriftartikelForskningpeer review

Harvard

Palk, EM, Andreasen, R, Rehkämper, M, Stunt, A, Kreissig, K, Coles, B, Schönbächler, M & Smith, C 2018, 'Variable Tl, Pb, and Cd concentrations and isotope compositions of enstatite and ordinary chondrites—Evidence for volatile element mobilization and decay of extinct205Pb', Meteoritics and Planetary Science, bind 53, nr. 2, s. 167-186. https://doi.org/10.1111/maps.12989

APA

Palk, E. M., Andreasen, R., Rehkämper, M., Stunt, A., Kreissig, K., Coles, B., Schönbächler, M., & Smith, C. (2018). Variable Tl, Pb, and Cd concentrations and isotope compositions of enstatite and ordinary chondrites—Evidence for volatile element mobilization and decay of extinct205Pb. Meteoritics and Planetary Science, 53(2), 167-186. https://doi.org/10.1111/maps.12989

CBE

MLA

Vancouver

Author

Palk, Emiliana Maria ; Andreasen, Rasmus ; Rehkämper, Mark ; Stunt, Alison ; Kreissig, Katharina ; Coles, Barry ; Schönbächler, Maria ; Smith, Caroline. / Variable Tl, Pb, and Cd concentrations and isotope compositions of enstatite and ordinary chondrites—Evidence for volatile element mobilization and decay of extinct205Pb. I: Meteoritics and Planetary Science. 2018 ; Bind 53, Nr. 2. s. 167-186.

Bibtex

@article{e140815b990b4826a66a7f2f93534b91,
title = "Variable Tl, Pb, and Cd concentrations and isotope compositions of enstatite and ordinary chondrites—Evidence for volatile element mobilization and decay of extinct205Pb",
abstract = "New Tl, Pb, and Cd concentration and Tl, Pb isotope data are presented for enstatite as well as L- and LL-type ordinary chondrites, with additional Cd stable isotope results for the former. All three chondrite suites have Tl and Cd contents that vary by more than 1-2 orders of magnitude but Pb concentrations are more uniform, as a result of terrestrial Pb contamination. Model calculations based on Pb isotope compositions indicate that for more than half of the samples, more than 50% of the measured Pb contents are due to addition of modern terrestrial Pb. In part, this is responsible for the relatively young and imprecise Pb-Pb ages determined for EH, L, and LL chondrites, which are hence only of limited chronological utility. In contrast, four particularly pristine EL chondrites define a precise Pb-Pb cooling age of 4559 +/- 6Ma. The enstatite chondrites (ECs) have highly variable epsilon Cd-114/110 of between about +3 and +70 due to stable isotope fractionation from thermal and shock metamorphism. Furthermore, nearly all enstatite meteorites display epsilon Tl-205 values from -3.3 to +0.8, while a single anomalous sample is highly fractionated in both Tl and Cd isotopes. The majority of the ECs thereby define a correlation of epsilon Tl-205 with epsilon Cd-114/110, which suggests that at least some of the Tl isotope variability reflects stable isotope fractionation rather than radiogenic ingrowth of Tl-205 from Pb-205 decay. Considering L chondrites, most epsilon Tl-205 values range between -4 and +1, while two outliers with epsilon Tl-205-10 are indicative of stable isotope fractionation. Considering only those L chondrites which are least likely to feature Pb contamination or stable Tl isotope effects, the results are in accord with the former presence of live Pb-205 on the parent body, with an initial Pb-205/Pb-204=(1.5 +/- 1.4)x10(-4), which suggests late equilibration of the Pb-Tl system 26-113Ma after carbonaceous chondrites (CCs). The LL chondrites display highly variable epsilon Tl-205 values from -12.5 to +14.9, also indicative of stable isotope effects. However, the data for three pristine LL3/LL4 chondrites display an excellent correlation between epsilon Tl-205 and Pb-204/Tl-203. This defines an initial Pb-205/Pb-204 of (1.4 +/- 0.3)x10(-4), equivalent to a Pb-205-Tl-205 cooling age of 55+12/-24Ma (31-67Ma) after CCs.",
keywords = "CADMIUM, CARBONACEOUS CHONDRITES, EARLY SOLAR-SYSTEM, FRACTIONATION, GEOLOGICAL-MATERIALS, IRON-METEORITES, SHOCK METAMORPHISM, THALLIUM, THERMAL METAMORPHISM, TRACE-ELEMENTS",
author = "Palk, {Emiliana Maria} and Rasmus Andreasen and Mark Rehk{\"a}mper and Alison Stunt and Katharina Kreissig and Barry Coles and Maria Sch{\"o}nb{\"a}chler and Caroline Smith",
year = "2018",
month = feb,
doi = "10.1111/maps.12989",
language = "English",
volume = "53",
pages = "167--186",
journal = "Meteoritics and Planetary Science",
issn = "1086-9379",
publisher = "JohnWiley & Sons, Inc.",
number = "2",

}

RIS

TY - JOUR

T1 - Variable Tl, Pb, and Cd concentrations and isotope compositions of enstatite and ordinary chondrites—Evidence for volatile element mobilization and decay of extinct205Pb

AU - Palk, Emiliana Maria

AU - Andreasen, Rasmus

AU - Rehkämper, Mark

AU - Stunt, Alison

AU - Kreissig, Katharina

AU - Coles, Barry

AU - Schönbächler, Maria

AU - Smith, Caroline

PY - 2018/2

Y1 - 2018/2

N2 - New Tl, Pb, and Cd concentration and Tl, Pb isotope data are presented for enstatite as well as L- and LL-type ordinary chondrites, with additional Cd stable isotope results for the former. All three chondrite suites have Tl and Cd contents that vary by more than 1-2 orders of magnitude but Pb concentrations are more uniform, as a result of terrestrial Pb contamination. Model calculations based on Pb isotope compositions indicate that for more than half of the samples, more than 50% of the measured Pb contents are due to addition of modern terrestrial Pb. In part, this is responsible for the relatively young and imprecise Pb-Pb ages determined for EH, L, and LL chondrites, which are hence only of limited chronological utility. In contrast, four particularly pristine EL chondrites define a precise Pb-Pb cooling age of 4559 +/- 6Ma. The enstatite chondrites (ECs) have highly variable epsilon Cd-114/110 of between about +3 and +70 due to stable isotope fractionation from thermal and shock metamorphism. Furthermore, nearly all enstatite meteorites display epsilon Tl-205 values from -3.3 to +0.8, while a single anomalous sample is highly fractionated in both Tl and Cd isotopes. The majority of the ECs thereby define a correlation of epsilon Tl-205 with epsilon Cd-114/110, which suggests that at least some of the Tl isotope variability reflects stable isotope fractionation rather than radiogenic ingrowth of Tl-205 from Pb-205 decay. Considering L chondrites, most epsilon Tl-205 values range between -4 and +1, while two outliers with epsilon Tl-205-10 are indicative of stable isotope fractionation. Considering only those L chondrites which are least likely to feature Pb contamination or stable Tl isotope effects, the results are in accord with the former presence of live Pb-205 on the parent body, with an initial Pb-205/Pb-204=(1.5 +/- 1.4)x10(-4), which suggests late equilibration of the Pb-Tl system 26-113Ma after carbonaceous chondrites (CCs). The LL chondrites display highly variable epsilon Tl-205 values from -12.5 to +14.9, also indicative of stable isotope effects. However, the data for three pristine LL3/LL4 chondrites display an excellent correlation between epsilon Tl-205 and Pb-204/Tl-203. This defines an initial Pb-205/Pb-204 of (1.4 +/- 0.3)x10(-4), equivalent to a Pb-205-Tl-205 cooling age of 55+12/-24Ma (31-67Ma) after CCs.

AB - New Tl, Pb, and Cd concentration and Tl, Pb isotope data are presented for enstatite as well as L- and LL-type ordinary chondrites, with additional Cd stable isotope results for the former. All three chondrite suites have Tl and Cd contents that vary by more than 1-2 orders of magnitude but Pb concentrations are more uniform, as a result of terrestrial Pb contamination. Model calculations based on Pb isotope compositions indicate that for more than half of the samples, more than 50% of the measured Pb contents are due to addition of modern terrestrial Pb. In part, this is responsible for the relatively young and imprecise Pb-Pb ages determined for EH, L, and LL chondrites, which are hence only of limited chronological utility. In contrast, four particularly pristine EL chondrites define a precise Pb-Pb cooling age of 4559 +/- 6Ma. The enstatite chondrites (ECs) have highly variable epsilon Cd-114/110 of between about +3 and +70 due to stable isotope fractionation from thermal and shock metamorphism. Furthermore, nearly all enstatite meteorites display epsilon Tl-205 values from -3.3 to +0.8, while a single anomalous sample is highly fractionated in both Tl and Cd isotopes. The majority of the ECs thereby define a correlation of epsilon Tl-205 with epsilon Cd-114/110, which suggests that at least some of the Tl isotope variability reflects stable isotope fractionation rather than radiogenic ingrowth of Tl-205 from Pb-205 decay. Considering L chondrites, most epsilon Tl-205 values range between -4 and +1, while two outliers with epsilon Tl-205-10 are indicative of stable isotope fractionation. Considering only those L chondrites which are least likely to feature Pb contamination or stable Tl isotope effects, the results are in accord with the former presence of live Pb-205 on the parent body, with an initial Pb-205/Pb-204=(1.5 +/- 1.4)x10(-4), which suggests late equilibration of the Pb-Tl system 26-113Ma after carbonaceous chondrites (CCs). The LL chondrites display highly variable epsilon Tl-205 values from -12.5 to +14.9, also indicative of stable isotope effects. However, the data for three pristine LL3/LL4 chondrites display an excellent correlation between epsilon Tl-205 and Pb-204/Tl-203. This defines an initial Pb-205/Pb-204 of (1.4 +/- 0.3)x10(-4), equivalent to a Pb-205-Tl-205 cooling age of 55+12/-24Ma (31-67Ma) after CCs.

KW - CADMIUM

KW - CARBONACEOUS CHONDRITES

KW - EARLY SOLAR-SYSTEM

KW - FRACTIONATION

KW - GEOLOGICAL-MATERIALS

KW - IRON-METEORITES

KW - SHOCK METAMORPHISM

KW - THALLIUM

KW - THERMAL METAMORPHISM

KW - TRACE-ELEMENTS

U2 - 10.1111/maps.12989

DO - 10.1111/maps.12989

M3 - Journal article

AN - SCOPUS:85049563008

VL - 53

SP - 167

EP - 186

JO - Meteoritics and Planetary Science

JF - Meteoritics and Planetary Science

SN - 1086-9379

IS - 2

ER -