Palaeozoic and Cenozoic lithoprobes and the loss of >120 km of Archaean lithosphere, Sino-Korean craton, China

TLDR

In eastern China, Palaeozoic kimberlites and Cenozoic basalts have erupted through the same Archaean crust, offering 400‑Ma deep probes of the cratonic lower lithosphere, whose remnants may survive as harzburgites chemically similar to Kaapvaal but distinct from newer lherzolites. Palaeozoic diamondiferous kimberlites indicate a thick, refractory lower lithosphere, whereas Cenozoic basalt‑borne xenoliths reveal a hot, thin, less refractory one; the dramatic Phanerozoic lithosphere reconfiguration is attributed to India‑Eurasia collision‑induced indentor tectonics, with passive reactivation of Archaean metasomes contributing to Cenozoic magmatism along major faults.

Abstract

Abstract In eastern China Palaeozoic kimberlites and Cenozoic basalts have been erupted through the same Archaean crust, thus providing deep probes of the cratonic lower lithosphere over a period of 400 Ma. While Palaeozoic diamondiferous kimberlites point to the existence of thick, refractory lower lithosphere in the east, Cenozoic basalt-borne xenoliths reveal the presence of hot, thin, less refractory lower lithosphere. Remnants of the Archaean lithosphere may have survived as harzburgites which are chemically similar to those from the Kaapvaal craton but very different from recently accreted lherzolites. In the absence of convincing evidence for supra-subduction or intraplate processes it is believed that the dramatic change of lithosphere architecture in the Phanerozoic was caused by indentor tectonics resulting from the collision of India and Eurasia. Passive reactivation and remobilization of the Archaean lower lithosphere, in particular metasome horizons, contributed to Cenozoic magmatism aligned along major lithospheric faults.