Figure 7. Sketch of Upper Cromarty depositional model. Upper Cromarty deposition is interpreted to have been sheet-like, c 80 feet thick within Bittern Field area. Red Lobe was deposited to the southeast of Bittern, having by-passed the field area. Majority of Upper Cromarty in 29/1b-2 is younger than that seen at Bittern. Isochore in 50-foot contours.