Internal structure of the Paleoarchean Mt Edgar dome, Pilbara Craton, Western Australia

Greenstone‐Up Shear Sense at the Margin of the Mt Edgar Dome, East Pilbara Terrane: Implications for Dome and Keel Formation in the Early Earth

“…Our results show that there is a pervasive greenstone-up sense of shear along much of the Mt Edgar dome margin. These results are interpreted and discussed in the context of a recently published study on the Mt Edgar dome's internal structures (Roberts & Tikoff, 2021).…”

“…The Emu Pool Supersuite (3.32–3.29 Ga) is variably deformed, with the northernmost units preserving a magmatic microstructure (Collins, 1989; Roberts & Tikoff, 2021). The Cleland Supersuite (3.28–3.23 Ga) is interpreted as the youngest dome‐related supersuite and preserves a magmatic microstructure overprinted by a weak solid state microstructure (Roberts & Tikoff, 2021). These three supersuites are considered to be “dome‐related” because their crystallization ages predate or are concurrent with the inferred timing of doming between 3.33 and 3.20 Ga (Hickman, 2012; Roberts & Tikoff, 2021).…”

“…The Cleland Supersuite (3.28–3.23 Ga) is interpreted as the youngest dome‐related supersuite and preserves a magmatic microstructure overprinted by a weak solid state microstructure (Roberts & Tikoff, 2021). These three supersuites are considered to be “dome‐related” because their crystallization ages predate or are concurrent with the inferred timing of doming between 3.33 and 3.20 Ga (Hickman, 2012; Roberts & Tikoff, 2021). The Split Rock Supersuite (2.89–2.83 Ga) granitoids are undeformed and are interpreted to be associated with a regional thermal event that occurred post‐doming (Hickman, 2012).…”

“…White dots with black outlines show locations of the U‐Pb zircon age dates collected by the Geological Survey of Western Australia, with age dates given in billions of years. Strike‐dip symbols show the trace and dip direction of foliation as determined by anisotropy of magnetic susceptibility (Roberts & Tikoff, 2021). LD = vertical lineation‐dominated zone of Roberts and Tikoff (2021).…”

“…The Callina/Tambina Supersuites (3.47-3.42 Ga) are banded migmatitic gneisses (Collins, 1989;Collins et al, 1998;Nelson, 1999Nelson, , 2000. The Emu Pool Supersuite (3.32-3.29 Ga) is variably deformed, with the northernmost units preserving a magmatic microstructure (Collins, 1989;Roberts & Tikoff, 2021). The Cleland Supersuite (3.28-3.23 Ga) is interpreted as the youngest dome-related supersuite and preserves a magmatic microstructure overprinted by a weak solid state microstructure (Roberts & Tikoff, 2021).…”