Rapid growth of some major segments of continental crust

Supercontinents, superplumes and continental growth: the Neoproterozoic record

“…Assuming that the Arabian-Nubian Shield extends to the Zagros Suture in Iran and comprises Neoproterozoic juvenile crust (35km thick), Reymer & Schubert (1986) calculated a crustal growth rate of 0.78km3/a, anomalously high for such a small volume of crust; similar rates were estimated by Stein & Goldstein (1996). Using only the exposed area of the Arabian Shield (0.6 X 106km2), Pallister et al (1990) estimate the rate to be only 0.07km3/a.…”

Formation and Evolution of the Continental Crust

“…(The compilation of Griffin et al (2013) is an exception in that its 2.5 Ga peak is larger, perhaps because this compilation contains abundant data from China and Australia, where zircons of this age are abundant). The 2.7 Ga peak registers a global event that affected rocks on all of the present-day continents (McCulloch and Wasserburg, 1978;Reymer and Schubert, 1986;Stein and Hofmann, 1994;Condie, 1998). Rocks formed at 2.7 Ga include a large amount of granitoid, much of which is said to be "juvenile".…”

“…One school relates them to episodic convection of the mantle which led to short spurts of accelerated crustal growth, separated by periods of geodynamic inactivity (Moorbath and Taylor, 1981;Reymer and Schubert, 1986;Stein and Hofmann, 1994;Condie, 1998). In this interpretation, the pulses of crustal growth are attributed to (1) superplumes from the deep mantle (e.g., Condie, 1998;Isley and Abbott, 1999), (2) return mantle flow triggered by slab avalanches (e.g., Stein and Hofmann, 1994;Davies, 1995;Condie, 2004) or (3) periods of accelerated plate motion and subduction (e.g., O'Neill et al, 2007).…”

Abu Hamamid Neoproterozoic Alaskan-type complex, south Eastern Desert, Egypt

“…However, some authors (e.g. Reymer and Schubert, 1986;Stein and Hofmann, 1994;Teklay et al, 2002;Stein, 2003) have argued for the implausibly high crustal growth rate of the ANS for simple arc-arc accretion model. They proposed that mantle plume magmatism should play an important role in the formation of juvenile ANS crust.…”