A deposit of sand cutting through sedimentary strata in the manner of an igneous dyke, formed by the filling of an underwater fissure.
- ‘Therefore we correlate the ash-fall episode recorded at Katraboca with that represented by the tuff filling the neptunian dyke of Liter.’
- ‘A neptunian dyke is a sheet of sediment or sedimentary rock, usually vertical or subvertical, which cuts across any other rock type and, at first glance, resembles an igneous dyke.’
- ‘The sample was collected from the redeposited tuff filling a neptunian dyke in the SW wall of the Liter quarry.’
- ‘Carbonates from the middle unit directly overlie volcanic rocks and consolidated Messinian marls, cross-cut by neptunian dykes with a bryozoan rudstone filling.’