Earth's Earliest Phaneritic Ultramafic Rocks. Mantle Slices or Crustal Cumulates?
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F22%3A00566414" target="_blank" >RIV/67985831:_____/22:00566414 - isvavai.cz</a>
Result on the web
<a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022GC010519" target="_blank" >https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022GC010519</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1029/2022GC010519" target="_blank" >10.1029/2022GC010519</a>
Alternative languages
Result language
angličtina
Original language name
Earth's Earliest Phaneritic Ultramafic Rocks. Mantle Slices or Crustal Cumulates?
Original language description
When plate tectonics initiated remains uncertain, partly because many signals interpreted as diagnostic of plate tectonics can be alternatively explained via hot stagnant-lid tectonics. One such signal involves the petrogenesis of early Archean phaneritic ultramafic rocks. In the Eoarchean Isua supracrustal belt (Greenland), some phaneritic ultramafic rocks have been dominantly interpreted as subduction-related, tectonically-exhumed mantle slices or cumulates. Here, we compared Eoarchean phaneritic ultramafic rocks from the Isua supracrustal belt with mantle peridotites, cumulates, and phaneritic ultramafic samples from the Paleoarchean East Pilbara Terrane (Australia), which is widely interpreted to have formed in non-plate tectonic settings. Our findings show that Pilbara samples have cumulate and polygonal textures, melt-enriched trace element patterns, relative enrichment of Os, Ir, and Ru versus Pt and Pd, and chromite-spinel with variable TiO2 and Mg#, and relatively consistent Cr#. Both, new and existing data show that cumulates and mantle rocks potentially have similar whole-rock geochemical characteristics, deformation fabrics, and alteration features. Geochemical modeling results indicate that Isua and Pilbara ultramafic rocks have interacted with low-Pt and Pd melts generated by sequestration of Pd and Pt into sulphide and/or alloy during magmatism. Such melts cannot have interacted with a mantle wedge. Correspondingly, geochemical compositions and rock textures suggest that Isua and Pilbara ultramafic rocks are not tectonically-exhumed mantle peridotites, but are cumulates that experienced metasomatism by fluids and co-genetic melts. Because such rocks could have formed in either plate or non-plate tectonic settings, they cannot be used to differentiate early Earth tectonic settings.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10505 - Geology
Result continuities
Project
<a href="/en/project/GA19-08066S" target="_blank" >GA19-08066S: Late Archean granites: markers of modern-style plate tectonics?</a><br>
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2022
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Geochemistry, Geophysics, Geosystems
ISSN
1525-2027
e-ISSN
1525-2027
Volume of the periodical
23
Issue of the periodical within the volume
12
Country of publishing house
US - UNITED STATES
Number of pages
28
Pages from-to
e2022GC010519
UT code for WoS article
000924664300001
EID of the result in the Scopus database
2-s2.0-85145020677