关键词: 克拉通破坏;拆沉;主动与被动裂谷作用;造山带伸展垮塌;华北

Abstract:

The destruction of the North China craton is a key problem in the continental geodynamics, which was realized from the comparison research of the lithosphere thickness, thermal gradient, age and components of the underneath mantle lithosphere between the Paleozoic and the Cenozic in eastern North China craton. As the huge amount of thinning of the lithosphere is regarded as one of the most important indicators of the destruction of the North China craton, several geodynamic models were proposed to account for the process of lithosphere thinning in last two decades. Meanwhile, since many other geological records formed during the destruction of the North China craton could not be explained reasonably by these geodynamic models, they could not be naturally treated as geodynamic models for the destruction of North China craton yet so far. Several important tectonic topics are supposed to be taken into consideration before an integrated geodynamic model for the destruction of North China craton is established, they are that (1) the active versus passive rifting model and the roles they played during the destruction of North China craton are supposed to be reevaluated based on detailed identifications of geological events sequences of tectonic deformation, sedimentation and volcanism, and the combination of the thermalchemical erosion model with aforementioned rifting model is expected to form an integrated candidate geodynamic model for the destruction of North China craton; that (2) in addition to the geochemical constraints, the spatial and temporal evolution of the plutonism and volcanism associated with delamination, rapid uplift of the crustal surface and related sedimentation and tectonic deformation should be systematically investigated to evaluate, revise and extend current lithosphere delamination model, and identification of high thermal anomaly expected from inferred delamination and the tectonic deformation responses of the thermal weakened crust caused by delamination to regional tectonic stress field, and the variations of stress derived from delamination as well, are supposed to be carried out toward a better construction of a delamination related geodynamic model; that (3) whether the destruction of North China craton was following an old stabilized craton or a mobile orogenic belt is a key to a better understanding of the process and mechanism of the destruction of North China craton, which require integrations of researches in regional tectonic deformation, syntectonic sedimentation and associated plutonism and volcanism; if the predestruction tectonics of eastern North China craton are of mobile orogenic belt characters, the extensional collapse of orogen should be taken into account during reconstructing the geodynamic process of the destruction of North China craton. 

Key words:

Key words: destruction of craton; delamination; active versus passive rifting; extensional collapse of orogen; North China