Evolution of the Crustal Blocks and Orogenic Belts through time
The map differs from geological, tectonic and terrane maps and emphasises the correlation of the great Eurasian belts. The units shown are therefore not tectono-stratigraphic terranes, but an individualisation of stable blocks and sedimentary and orogenic prisms. The map is oriented towards a global readability of the tectonic belts that contributed to the continental growth of eastern Eurasia.
Stable blocks and zones represent units of continental crust that have behaved as rigid entities during major orogens and constitute the autochthonous of sedimentary or orogenic prisms. These units are separated by orogenic belts on the map, but do not represent a specific age. Thus, the cores of the main cratons formed during the Precambrian are represented, but also crustal blocks or oceanic plateaus individualised more recently, and responsible for the shortening of the prisms.
Prisms and orogens include accretionary prisms developed offshore in subduction zones but also onshore in orogenic belts. They represent products of subduction regardless of the nature - oceanic or continental - of the crusts involved. They mostly represent deformed belts of sediments, metamorphosed or not, currently overlapping continental crusts. Orogenic prisms may also involve crustal strips of continental crust. In complex areas, especially in the early Phanerozoic, orogenic belts are highly metamorphosed and can be considered 'cratonised'.
The Rifts have been compiled, generalised and classified by age where possible. Choices had to be made when information was missing, unclear, or contradictory. Many faults have also been reactivated; the colour indicates the age of the dominant event.
The sutures have also been classified chronologically, but the age may vary significantly along them as a result of migration of the docking. In ancient belts, by erosion, they represent the boundary of juxtaposed or overlapped crusts. Their course is approximate and may pass through several alignments of ophiolithic massifs, highlighting either their allochthonous position or the existence of arc/back-arc system closures.
The metamorphic facies are indicated by coloured dots - indicating the dominant facies - so as not to load and obscure the structural information.