Subcontinental lithosphere, models

However, the information conveyed by mantle xenoliths indicates that stable subcontinental lithosphere is dominated by refractory peridotites which are enriched in HIE and LREE and have often acquired an enriched isotopic signature as a result of time integration of their chemical enrichment (see Chapter 2.05). Therefore, an alternative to the porous-flow model is to consider that the harzburgite layers represent strips of lithospheric peridotites embedded into more fertile material derived from the asthenospheric mantle (e.g., the Lherz massif, Eigure 30). In this scheme, the and Sr/ Sr versus... 

Current models for the formation and evolution of subcontinental lithosphere... 

A potentially significant reservoir, and one which a number of authors have suggested is important in the context of continent formation, is the subcontinental lithospheric mantle (SCLM). Kramers (1987, 1988), suggested that the TTG magmas of the Archaean crust formed in an open-system magma layer in the early Earth, the cumulates from which are now preserved as the SCLM. More recently Abbott et al. (2000) proposed a model of continental growth founded upon the premise that the continental crust was extracted from the SCLM. 

To explain the denudation of peridotites on the seafloor before the onset of oceanic accretion, Lemoine et al. (1987) and Trommsdorff et al. (1993) proposed a model involving extensional exhumation of subcontinental mantle along a major, normal detachment fault rooted in the crust-mantle boundary (Wernicke, 1981,1985). In most cases, however, the peridotites record a higher-temperature evolution than would be expected from stable lithospheric mantle. This suggests that ... 

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