The archipelago is characterised by numerous contemporaneous volcanoes, some with plume magma sources, others from the asthenosphere
, possibly due to the young and thin oceanic crust.
Therefore, quartz diorite might be formed in the post-collision extension environment after the collision of Lhasa block and Qiangtang block; lower crust delamination caused uplifting of asthenosphere
material, which further caused partial melting of lithospheric mantle and let basic melt mix with the acid melt.
Prograde metamorphism of the bounding thick crust may have led to formation of a dense, eclogitic lower crustal root that had detached from the more buoyant overlying granulitic crust and sank, together with its attached underlying lithospheric mantle, into the convecting asthenosphere
of the backarc region (see Krystopowicz and Currie 2013).
A tectonomagmatic model is proposed wherebyEoceneNisai intrusions have been generated through processes of subduction-related flux melting and localized extension through plate flexure, providing necessary deep melting of the upper asthenosphere
2014: The importance of slab pull and a global asthenosphere
to plate motions.
Although the lithosphere and asthenosphere
have to be distinguished by the viscosity, imaging the Earth's structure in terms of viscosity provides only weak resolution even with the most recent technology, (25) compared with seismic or electromagnetic imaging methods.
The dense crust would have dripped down into the mantle, triggering a return flow of mantle material from the asthenosphere
that would have melted to form new primary crust.
is where rock behaves like putty, slowly deforming under heat and pressure.
So, rather than 'check in' where I really am (which would mean either adding it to the list of nearby places, or, presumably - I'll admit I'm a little sketchy on the details - waiting for some science to occur in the asthenosphere
, or something) I decide it would be amusing to pretend we're in Tenby, engaged in a stained-carpet-related mission.
Within this anomaly, magmatic material from the asthenosphere
(upper mantle) is slowly rising and invading the lithosphere--the crust and uppermost mantle.
The concept of continental delamination was introduced by Bird (1978, 1979), who proposed that the dense lithospheric mantle might peel off the crust and sink into the underlying asthenosphere
, as soon as any process provided an elongated 'asthenospheric conduit' connecting the asthenosphere
with the base of the continental crust.
Many zones of higher confidence can be seen at depths shallower than around 150 km, suggesting that the boundary between the lithosphere and the asthenosphere
is approximately at that depth.