According to the gravity and seismic profiles, ARGCs represent upper parts of large transcrustal magmatic systems, composed of alternating basic and silicic rocks layers. They are located over mantle uplift structures 10–20 km high, interpreted to represent former mantle plume heads. Origin of transcrustal systems was probably linked with penetrating sill-like bodies of Fe–Ti basalts, which after intruding into sialic crust, caused large-scale re-melting of the granitic material above them, forming two-layer magma chambers. Solidification of such chambers occurred in two stages: lower basic layers solidified first while heated from below, whereas the upper silicic layer crystallized later. Co-existing neighboring chambers led to gravitational instability, overturn, and mass redistribution in large volumes of crust. Furthermore, multistage formation of the ARGCs led to important petrological consequences: contamination of basic magmas by crustally derived SiO2 and Al2O3, causing preferred precipitation of plagioclase and formation of plagioclase cumulates (anorthosites). Diffusion of Na into the basic melt and K into the silicic melt led to the appearance of potassic rapakivi granites.
ARGCs on all Precambrian shields were developed in places with stabilized Paleoproterozoic orogens with atypical unusually thick crust compared with the Phanerozoic, and associated with large Mesoproterozoic belts of within-plate felsic volcanism. Under these conditions, the majority of mantle plume-derived mafic magmas were not able to reach the surface and were lost within the crust in the form of sill-like intrusions with zones of intense melting of a sialic roof. Evidently, ARGCs illustrate structure and processes that are not repeated in the Phanerozoic.