Abstract. The North China Craton (NCC) is one of the oldest cratons
in the world. Currently, the destruction mechanism and geodynamics of the
NCC remain controversial. All of the proposed views regarding the issues
involve studying the internal density structure of the NCC lithosphere.
Gravity field data are among the most important data in regard to
investigating the lithospheric density structure, and gravity gradient data
and gravity data each possess their own advantages. Given the different observational plane heights between the on-orbit GOCE
(Gravity Field and Steady-State Ocean Circulation Explorer) satellite gravity gradient and terrestrial gravity and the effects of the
initial density model on the inversion results, sequential inversion of the
gravity gradient and gravity are divided into two integrated processes. By
using the preconditioned conjugate gradient (PCG) inversion algorithm, the
density data are calculated using the preprocessed corrected gravity anomaly
data. Then, the newly obtained high-resolution density data are used as the
initial density model, which can serve as constraints for the subsequent
gravity gradient inversion. Several essential corrections are applied to the
four gravity gradient tensors (Txx, Txz, Tyy, Tzz) of the GOCE satellite, after which
the corrected gravity gradient anomalies (T′xx, T′xz, T′yy, T′zz) are used
as observations. The lithospheric density distribution result within the
depth range of 0–180 km in the NCC is obtained. This study clearly illustrates that GOCE data are helpful in understanding
the geological settings and tectonic structures in the NCC with regional
scale. The inversion results show that in the crust the eastern NCC is
affected by lithospheric thinning with obvious local features. In the
mantle, the presented obvious negative-density areas are mainly affected by
the high-heat-flux environment. In the eastern NCC, the density anomaly in
the Bohai Bay area is mostly attributed to the extension of the
Tancheng–Lujiang major fault at the eastern boundary. In the western NCC,
the crustal density anomaly distribution of the Qilian block is consistent
with the northwest–southeast strike of the surface fault belt, whereas such
an anomaly distribution experiences a clockwise rotation to a nearly
north–south direction upon entering the mantle.
Inversion of the density structure of the lithosphere in the North China Craton from GOCE satellite gravity gradient data
