Analytical data of lamprophyres (minette and spessartite) display a primitive character and are enriched in LILE with depleted HFSE. The geotectonic environment as suggested by trace element data suggests both subduction and rift settings.
"Geochemical evidence for deep mantle melting and lithospheric delamination as the origin of the inland Damavand volcanic rocks of northern Iran" (Mirnejad et al., 2010).
It seems like the section «5.3. Deep mantle melting and lithospheric delamination» has the necessary links and explanations.
Thank you F Stoppa and Nester Korolev for your replies and links.
Delamination model: Model where the dense root of an orogen detaches and sinks into the underlying mantle. To have more (H. Fossen, 2010. Structural geology page 350)
A model that works well in central Laurentia (Churchill Province), which contains a large Paleoproterozoic late syncollisional minette volcanic province with crustal IE and Nd isotopic features, but mantle-like mg numbers, is imbrication of lower crust with upper mantle, by both thrusting and detachment faulting. Model is supported by the presence of UHP diamonds in the minettes and structural/metamorphic data indicating substantial prior crustal thickening, and uplift exhuming granulite facies terrains. The boundaries between the imbricate panels should be sites of formation of glimmerite bodies (alkalies, IE from the crust; Mg, CE from the mantle), which are a good candidate for a source region for the minettes and are common as xenoliths in them. Seismic imaging of the Tibetan Plateau, which has been cited as an analogue for the CP, clearly shows imbrication of the Moho directly underneath the location of young ultrapotassic magmatism. The heat trigger to melt the glimmerites may have been subsequent lithosphere delamination. References and more details are in a hastily written contribution to the LIP website:
http://www.largeigneousprovinces.org/10dec
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