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Lu-Hf apatite geochronology of mafic cumulates: An example from a Fe-Ti mineralization at Smalands Taberg, southern Sweden

Larsson, Daniel LU and Söderlund, Ulf LU (2005) In Chemical Geology 224(4). p.201-211
Abstract
We have employed Lu-Hf apatite chronology to determine the age of a magnetite-rich melatroctolite in southern Sweden, known as the Smalands Taberg Fe-Ti ore deposit. The melatroctolite is poor in incompatible elements and minerals forming at more advanced stages of differentiation, which precludes the use of minerals (baddeleyite, zircon, titanite or apatite) commonly used for dating the emplacement of igneous rocks. Enclaves of leucogabbro in the melatroctolite have REE patterns parallel with the host melatroctolite and identical initial Hf and Nd isotope compositions. These characteristics are conclusive evidence for a common parental magma. The leucogabbro is a slightly more evolved facies that underwent limited fractionation of olivine... (More)
We have employed Lu-Hf apatite chronology to determine the age of a magnetite-rich melatroctolite in southern Sweden, known as the Smalands Taberg Fe-Ti ore deposit. The melatroctolite is poor in incompatible elements and minerals forming at more advanced stages of differentiation, which precludes the use of minerals (baddeleyite, zircon, titanite or apatite) commonly used for dating the emplacement of igneous rocks. Enclaves of leucogabbro in the melatroctolite have REE patterns parallel with the host melatroctolite and identical initial Hf and Nd isotope compositions. These characteristics are conclusive evidence for a common parental magma. The leucogabbro is a slightly more evolved facies that underwent limited fractionation of olivine and titanomagnetite; the two major mineral phases in the melatroctolite. Apatite and plagioclase, separated from the leucogabbro, plus a whole-rock sample define a Lu-Hf isochron with a slope corresponding to an age of 1204.3 +/- 1.8 Ma. This result is close to the lower age boundary previously reported for this magmatic event comprising dolerites, syenites and granites. The Lu-Hf apatite chronometer merits attention as a new tool in generating accurate and precise ages for igneous, silica-undersaturated rocks that may be difficult to date with traditional techniques. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
melatroctolite, Lu-Hf geochronology, apatite, Fe-Ti mineralization
in
Chemical Geology
volume
224
issue
4
pages
201 - 211
publisher
Elsevier
external identifiers
  • wos:000234119200002
  • scopus:29544441454
ISSN
0009-2541
DOI
10.1016/j.chemgeo.2005.07.007
language
English
LU publication?
yes
id
02b7ab47-8fbc-4559-9731-f940bed9feda (old id 210588)
date added to LUP
2007-08-16 14:14:00
date last changed
2017-11-19 03:33:30
@article{02b7ab47-8fbc-4559-9731-f940bed9feda,
  abstract     = {We have employed Lu-Hf apatite chronology to determine the age of a magnetite-rich melatroctolite in southern Sweden, known as the Smalands Taberg Fe-Ti ore deposit. The melatroctolite is poor in incompatible elements and minerals forming at more advanced stages of differentiation, which precludes the use of minerals (baddeleyite, zircon, titanite or apatite) commonly used for dating the emplacement of igneous rocks. Enclaves of leucogabbro in the melatroctolite have REE patterns parallel with the host melatroctolite and identical initial Hf and Nd isotope compositions. These characteristics are conclusive evidence for a common parental magma. The leucogabbro is a slightly more evolved facies that underwent limited fractionation of olivine and titanomagnetite; the two major mineral phases in the melatroctolite. Apatite and plagioclase, separated from the leucogabbro, plus a whole-rock sample define a Lu-Hf isochron with a slope corresponding to an age of 1204.3 +/- 1.8 Ma. This result is close to the lower age boundary previously reported for this magmatic event comprising dolerites, syenites and granites. The Lu-Hf apatite chronometer merits attention as a new tool in generating accurate and precise ages for igneous, silica-undersaturated rocks that may be difficult to date with traditional techniques.},
  author       = {Larsson, Daniel and Söderlund, Ulf},
  issn         = {0009-2541},
  keyword      = {melatroctolite,Lu-Hf geochronology,apatite,Fe-Ti mineralization},
  language     = {eng},
  number       = {4},
  pages        = {201--211},
  publisher    = {Elsevier},
  series       = {Chemical Geology},
  title        = {Lu-Hf apatite geochronology of mafic cumulates: An example from a Fe-Ti mineralization at Smalands Taberg, southern Sweden},
  url          = {http://dx.doi.org/10.1016/j.chemgeo.2005.07.007},
  volume       = {224},
  year         = {2005},
}