**4. Summary**

Passive seismic source investigations using teleseismic data revealed heterogeneous structure in LHB. Depth variations of the upper mantle discontinuities (both for 410 and 660 km) were derived by long-period receiver functions by using local array network at the area. Shallow depths in topography of upper mantle discontinuity were identified at the continental back azimuth beneath the ice sheet. The evidence reflected the effect by paleo-upwelling flow associating the mantle plume with regard to the Gondwana breakup. Lithospheric mantle anisotropy derived by the SKS splitting was supposed to be formed by "fossil" anisotropy caused by the past tectonics in NE-SW orientation. The origin of the mantle anisotropy was assumed by the LPO involving the process of supercontinent assembly rather than present asthenospheric flow which parallel with the absolute plate motion on the Earth's surface. In addition, several results from deep seismic surveys by using active seismic sources which were carried out on the continental ice sheet provided clear information on crust-mantle boundary, in addition to the inner lithospheric mantle seismic reflections. After processing of deep seismic reflections, the extracted lithospheric cross section implied tectonic influence of compressive stress during Pan-African age.
