PT  - JOURNAL ARTICLE
AU  - Shao, J.
AU  - He, G.
AU  - Zhang, L.
TI  - Deep crustal structures of the Yanshan intracontinental orogeny: a comparison with pericontinental and intercontinental orogenies
AID  - 10.1144/SP280.9
DP  - 2007 Jan 01
TA  - Geological Society, London, Special Publications
PG  - 189--200
VI  - 280
IP  - 1
4099  - http://sp.lyellcollection.org/content/280/1/189.short
4100  - http://sp.lyellcollection.org/content/280/1/189.full
SO  - Geological Society, London, Special Publications2007 Jan 01; 280
AB  - The Mesozoic Yanshan intracontinental orogenic belt is developed in a weak zone on the northern margin of the North China Craton. We classify the Yanshan as an intracontinental orogen, as opposed to an intercontinental or pericontinental orogen, because of several geodynamic factors that differ from those of typical intercontinental orogens. These are: (1) reactivated tectonic activity on the lithospheric-scale faults since 1.8 Ga; (2) differential uplift of blocks during the Mesozoic, especially the great change of the elevation–subsidence framework at about 140 Ma, which induced building of the Yanshan Mountain and formation of the Cretaceous basins; (3) polycyclic evolutionary processes of active rift basins recorded by the Mesozoic volcanic and sedimentary strata; (4) Mesozoic tectonic regime reversion in the eastern North China Craton, demonstrated by petrological and geochemical evidence of crust–mantle interaction and supported by research on lithosphere thinning and ancient heat flow. Among these factors, the acute tectonic events of the lithosphere and evolution of active rift basins are directly affected by the upper mantle. The differential elevation of faulted blocks directly reflects the deep tectonic processes. Inherited features of the tectonic activities are characteristic of intracontinental orogenies and occur throughout all stages of the Yanshan movement but with different features. The deep controlling factors changed with time and combined with each other. The depth of tectonomagmatic activity became progressively shallower from 180 Ma to 130 Ma and then became deep again after 120 Ma. In the same period, extensional deformation was predominant in this area. The most important geodynamic characteristic of the Yanshan intracontinental orogeny is the tectonic regime inversion. Intracontinental orogeny is the response of the upper crust to the dramatic movements of the deep lithosphere. Its essential tectonic processes are thickening and subsequent thinning of the crust and lithosphere, which induces not only deformation of the rocks but also uplift of the mountain chain. Magmatic underplating is the most important factor of the Yanshan orogeny.