Cross Section A-B

This cross section shows the wedge of  porous Yesnaby Sandstone caped and under-sealed by impervious sediments. The Yesnaby Sandstone forms a classic "Combination Trap" for oil accumulation - both stratigraphic and structural in nature.


The aeolian (desert) and fluvial (river) deposited sands of the Yesnaby Sandstone commonly are blackened by solid bitumen indicating the former presence of hydrocarbon liquids (crude oil).