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. 2018 Oct 1;376(2132):20180103. doi: 10.1098/rsta.2018.0103

Table 1.

Definition of terms used in this paper.

term definition in this contribution
TTG tonalite–trondhjemite–granodiorite; a plutonic rock series that is characterized by high Na2O/K2O;
towards the Mid- to Late Archaean elevated Sr/Y and heavy rare-earth element depletion through retention in residual garnet and/or amphibole during partial melting become increasingly common
proposed to be derived from melting of (hydrous) mafic successions
trondhjemites versus tonalites may be a function of pressure of melting
transitional TTG similar to TTG, but with a spectrum of K content intermediate between TTG and ACP granites
within Archaean Domes typically offset from TTG melts by 100–300 Ma, in the North Kaapvaal craton of South Africa often dispersed within TTG gneisses
sanukitoids potassic diorites with elevated Mg, Cr and Ni;
Proposed to have formed by interactions of TTG melt with peridotite. The sanukitoids s.s. are the root of a series of more differentiated rocks (sanukitoid suite)
ACP granites or high-K granites Archaean crustal progeny granites, formed by remelting of earlier, silicic crust. Plutonic rocks with a markedly elevated K content compared to TTG. Plausible petrogenetic models to create elevated K contents granitic melts towards the Mid- to Late Archaean argue for a re-melting of earlier TTG succession. For this, petrologic phase equilibria require either excess heat in TTG-bearing crust, or elevated pressure–temperature through subsidence
stagnant lid the entire lithosphere of the planet that covers the mantle as a lid without active tectonics. Sporadic subduction is possible; the lid is characterized by felsic intrusions into a stationary lithosphere
(down- or lithospheric) drips drip of the lowermost lithosphere into the underlying mantle, initiated by converging convection cells. These drips have a limited lifespan of several hundreds of millions of years and occur randomly between rather small convection cells
downwellings similar to drips, but with a substantially longer lifespan and stationary at the interface between thick and thin plates, i.e. a proto-craton and a proto-plate
lithosphere the outermost shell of the planet, including the crust and its underlying, non-convecting mantle
lithospheric mantle the rigid, non-convecting part of the lithosphere, underpinning the crust. In post-Archaean time, this is often termed sub-continental lithospheric mantle
proto-craton former part of a stagnant lid regime that thickens due to melt injection and intra-crustal flow. This part is today preserved as cratons and can date back to the early Archaean, even with Hadean components
proto-oceanic crust former part of the stagnant lid that thins out though thermal erosion, e.g. via plumes, or through intra-crustal flow. Proto-oceanic crust have been destroyed through subduction, with modern oceanic crust as analogues