### Abstract

We reviewed here the recent development on the mathematical formulation of closure temperature of a cooling geochronological system, which permits direct retrieval of cooling rate from cooling age when the diffusion parameters, grain size and initial temperature are known. This formulation is used to show how the cooling rate can be retrieved by comparing the core and bulk age of a mineral determined by a single decay system. The cooling rates of seven H chondrites of the metamorphic types H4, H5 and H6 were retrieved from the available data on the Pb-Pb model ages of the phosphates and the diffusion kinetic data of Pb in apatite. The results are in excellent agreement with the metallographic cooling rates and show an inverse relation with the metamorphic grade of these chondrites. We also addressed the problem of ∼90 Ma younger Sm-Nd mineral isochron age, defined by orthopyroxene, phosphate and plagioclase, of the Morristown mesosiderite compared to the Pb-Pb age of the Estherville mesosiderite. It is shown that this younger age could have been a consequence of resetting during cooling instead of an "impulsive heating" event, as suggested earlier.

Original language | English (US) |
---|---|

Pages (from-to) | 167-175 |

Number of pages | 9 |

Journal | Meteoritics and Planetary Science |

Volume | 36 |

Issue number | 1 |

State | Published - 2001 |

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### ASJC Scopus subject areas

- Geophysics

### Cite this

*Meteoritics and Planetary Science*,

*36*(1), 167-175.

**Relationship between cooling rate and cooling age of a mineral : Theory and applications to meteorites.** / Ganguly, Jibamitra; Tirone, M.

Research output: Contribution to journal › Article

*Meteoritics and Planetary Science*, vol. 36, no. 1, pp. 167-175.

}

TY - JOUR

T1 - Relationship between cooling rate and cooling age of a mineral

T2 - Theory and applications to meteorites

AU - Ganguly, Jibamitra

AU - Tirone, M.

PY - 2001

Y1 - 2001

N2 - We reviewed here the recent development on the mathematical formulation of closure temperature of a cooling geochronological system, which permits direct retrieval of cooling rate from cooling age when the diffusion parameters, grain size and initial temperature are known. This formulation is used to show how the cooling rate can be retrieved by comparing the core and bulk age of a mineral determined by a single decay system. The cooling rates of seven H chondrites of the metamorphic types H4, H5 and H6 were retrieved from the available data on the Pb-Pb model ages of the phosphates and the diffusion kinetic data of Pb in apatite. The results are in excellent agreement with the metallographic cooling rates and show an inverse relation with the metamorphic grade of these chondrites. We also addressed the problem of ∼90 Ma younger Sm-Nd mineral isochron age, defined by orthopyroxene, phosphate and plagioclase, of the Morristown mesosiderite compared to the Pb-Pb age of the Estherville mesosiderite. It is shown that this younger age could have been a consequence of resetting during cooling instead of an "impulsive heating" event, as suggested earlier.

AB - We reviewed here the recent development on the mathematical formulation of closure temperature of a cooling geochronological system, which permits direct retrieval of cooling rate from cooling age when the diffusion parameters, grain size and initial temperature are known. This formulation is used to show how the cooling rate can be retrieved by comparing the core and bulk age of a mineral determined by a single decay system. The cooling rates of seven H chondrites of the metamorphic types H4, H5 and H6 were retrieved from the available data on the Pb-Pb model ages of the phosphates and the diffusion kinetic data of Pb in apatite. The results are in excellent agreement with the metallographic cooling rates and show an inverse relation with the metamorphic grade of these chondrites. We also addressed the problem of ∼90 Ma younger Sm-Nd mineral isochron age, defined by orthopyroxene, phosphate and plagioclase, of the Morristown mesosiderite compared to the Pb-Pb age of the Estherville mesosiderite. It is shown that this younger age could have been a consequence of resetting during cooling instead of an "impulsive heating" event, as suggested earlier.

UR - http://www.scopus.com/inward/record.url?scp=0035067278&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0035067278&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0035067278

VL - 36

SP - 167

EP - 175

JO - Meteoritics and Planetary Science

JF - Meteoritics and Planetary Science

SN - 1086-9379

IS - 1

ER -