Structural Aspects of the Intraplate Deformations of the Oceanic Crust North of the Afanasii Nikitin Rise (Inidan Ocean)

摘要

On the basis of the tectonic interpretation of the continuous seismic profiling data wiht account for the data of deep seismic sounding,we assessed the structure of the test area Sh-22-I of the Labrador Current in the region of the recent intraplate deformations of the Indian Ocean lithosphere northeast of the Afansii Nikitin Rise(Mid-Indian Basin).The possibility of the existence of wide diffuse sinistral shears over ancient transform faults was revealed,which proves their recent tectonic reactivation.The concept of the significant structure-forming role of the processes of serpentinization of the ultramafic rocks of the lower crust and upper mantle and diagonal shears is developed.We show the complicated tectonic interrelations between the young (recent tectonic) compressional structural pattern and that of the ancient Late Cretaceous spreading in the Mid-Indian Basin.The structural relations between the deep crustal inhomogeneities and their manifestation in the recent compressional structures of the sedimentary cover are illustrated.