Stratigraphic and structural analysis of the Late Palaeozoic-Mesozoic of NE Wales and Liverpool Bay: implications for hydrocarbon prospectivity

Abstract: Interpretation f seismic lines from the offshore NE Wales area has provided information on the structural and stratigraphic evolution of the southern part of Morecambe/Liverpool Bay. Basin-wide megasequence boundaries are present between the Dinantian and overlying sequences and between the Upper Carboniferous and Permo-Triassic megasequences. Geological information ob-tained from seismic lines has been used to construct an E-W geological cross section and a basin analysis ummary chart for the NE Wales-Cheshire onshore area. Stratigraphic nterpretations have been considered in an assessment of the petroleum potential of the region. The distribution of Carboniferous oil and gas prone source rocks is a key element in predicting hydrocarbon accumula-tions. Source rock maturity may have been reached in the offshore area prior to a phase of inversion and uplift during Tertiary times. Fault-controlled hydrocarbon traps generated uring Triassic-Jurassic rifting were modified uring Tertiary inversion and new structures were generated. The area of interest includes the counties of Clwyd and Cheshire and the southern portion of Liverpool Bay delimited by a line between Great Ormes Head and Formby (Fig. 1). Geology and topography are closely related in the area with the Denbigh Moors and Clwydia