Extrusion of subducted crust explains the emplacement of far-travelled ophiolites

Fragments of oceanic lithosphere (ophiolites) overlying continents are frequent but enigmatic elements in the mountain belts of Earth
Interpreted output of numerical simulations showing the evolution from the initial uplift of the continental crust (a) to the emplacement of the far-travelled ophiolite sheet (c).

Ophiolite fragments are often found on top of continents far from the main ophiolite nappe (far-travelled ophiolites), while the continental crust experiences burial and exhumation below the oceanic lithosphere. The researchers have investigated the relation between the exhumation of the continental crust and the emplacement of far-travelled ophiolites by combining geological datasets with geodynamic models (numerical simulations). They found that the buried continental crust in a convergent setting starts to exhume due to its natural buoyancy, which leads to uplift, extension, and finally breaking of the overlying oceanic lithosphere. The broken-off piece of oceanic lithosphere is then transported on top of the continent as dictated by the exhumation (extrusion) of the continental crust, and hence becomes a far-travelled ophiolite sheet.

Reference : Extrusion of subducted crust explains the emplacement of far-travelled ophiolites. Kristóf Porkoláb, Thibault Duretz, Philippe Yamato, Antoine Auzemery & Ernst Willingshofer. Nature Communications volume 12, Article number: 1499 (2021). https://www.nature.com/articles/s41467-021-21866-1