Coronae on Venus: formation by lithospheric drag from convective cells in the mantle

Abstract

I propose a new model of coronae formation on Venus. It assumes a cylindrical convective cell centred on a hot spot. Lithosphere is dragged down radially at the top of the cell by the horizontal movement of the mantle producing the ring of hills and the interior cavity. As the material is cooled it descends, folding the lithosphere at the rim of the corona and creating a circular moat. This mechanism cannot occur on the Earth, because of the motion of lithospheric plates, nor on Mercury, Moon or Mars because of the thickness of their lithospheres.