Moho depth model and lithospheric structures from GOCE gravity gradient data for the Central Asian Orogenic Belt
The Central Asian Orogenic Belt (CAOB) is an accretionary orogen covering one third of Asia. Guy et al. (2014) demonstrate by the correlation between geology and potential field data that the systematic use of lithostratigraphic terranes to define the CAOB is not appropriate.
However, the geophysical investigations remain scarce due to the remoteness of the area and a systematic analysis of the crustal thickness has been yet omitted. The geometry of the crust-mantle boundary (Moho boundary) provides key information on the evolution of the lithosphere, and therefore determining the Moho geometry and the isostatic state of the CAOB is crucial for the understanding of its tectonic history. In absence of dense seismic coverage, gravity data provide an alternative way to model the depth to the Moho and investigate deep crustal and upper mantle anomalies.
The Gravity field and steady-state Ocean Circulation Explorer (GOCE) is the European Space Agency’s (ESA) satellite gravity mission to determine the Earth’s mean gravity field. Among other things, GOCE delivers gravitational gradients data which are the first satellite data of this nature. These data can improve the modelling of the Earth’s lithosphere in two major aspects: (1). Update the Moho depth model; (2). Analyse the gravity anomalies located at the upper mantle and lower crustal levels.