Anisotropy in the flexural response of the Indian Shield

We seek to determine the strain field which has accumulated in the Indian Shield due to the continental drift of Gondwanaland. We have used a method which involves the calculation of the 2D isostatic coherence response function between Bouguer gravity and topography as a function of azimuth by way of multispectrogram analysis. The average coherence is maximum consistently in the Indian Shield in a direction, which is at an angle of 45° to the major trend of suture zones within the shield, a result which is in good agreement with the strain inferred from absolute plate motion (APM) in a hot spot reference frame. This directionality of mechanical plate weakness suggests that all paleostress fields were erased due to the movement of the Indian plate during the Himalayan orogeny.

► Flexural anisotropy. ► Indian Shield. ► Hermite multitapers. ► Seismic anisotropy. ► Bouguer coherence.