The Juvenile Hafnium Isotope Signal as a Record of Supercontinent Cycles.

Title The Juvenile Hafnium Isotope Signal as a Record of Supercontinent Cycles.
Authors N.J. Gardiner; C.L. Kirkland; M.J. Van Kranendonk
Journal Sci Rep
DOI 10.1038/srep38503

Hf isotope ratios measured in igneous zircon are controlled by magmatic source, which may be linked to tectonic setting. Over the 200-500?Myr periodicity of the supercontinent cycle - the principal geological phenomenon controlling prevailing global tectonic style?-?juvenile Hf signals, i.e. most radiogenic, are typically measured in zircon from granites formed in arc settings (crustal growth), and evolved zircon Hf signals in granites formed in continent-collision settings (crustal reworking). Interrogations of Hf datasets for excursions related to Earth events commonly use the median value, however this may be equivocal due to magma mixing. The most juvenile part of the Hf signal is less influenced by crustal in-mixing, and arguably a more sensitive archive of Earth's geodynamic state. We analyze the global Hf dataset for this juvenile signal, statistically correlating supercontinent amalgamation intervals with evolved Hf episodes, and breakup leading to re-assembly with juvenile Hf episodes. The juvenile Hf signal is more sensitive to Pangaea and Rodinia assembly, its amplitude increasing with successive cycles to a maximum with Gondwana assembly which may reflect enhanced subduction-erosion. We demonstrate that the juvenile Hf signal carries important information on prevailing global magmatic style, and thus tectonic processes.

Citation N.J. Gardiner; C.L. Kirkland; M.J. Van Kranendonk.The Juvenile Hafnium Isotope Signal as a Record of Supercontinent Cycles.. Sci Rep. 2016;6:38503. doi:10.1038/srep38503

Related Elements


See more Hafnium products. Hafnium (atomic symbol: Hf, atomic number: 72) is a Block D, Group 4, Period 6 element with an atomic weight of 178.49. Hafnium Bohr ModelThe number of electrons in each of Hafnium's shells is 2, 8, 18, 32, 10, 2 and its electron configuration is [Xe] 4f14 5d2 6s2. The hafnium atom has a radius of 159 pm and a Van der Waals radius of 212 pm. Hafnium was predicted by Dmitri Mendeleev in 1869 but it was not until 1922 that it was first isolated Dirk Coster and George de Hevesy. In its elemental form, hafnium has a lustrous silvery-gray appearance. Elemental HafniumHafnium does not exist as a free element in nature. It is found in zirconium compounds such as zircon. Hafnium is often a component of superalloys and circuits used in semiconductor device fabrication. Its name is derived from the Latin word Hafnia, meaning Copenhagen, where it was discovered.

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