This report describes a study of the Scremerston Formation and lower part of the overlying
Yoredale Formation at outcrop and in the onshore subsurface in the Berwick-upon-Tweed area
of north-east Northumberland. The work was carried out on behalf of Sterling Resources Ltd and
partners, who were interested in the onshore succession as an analogue to similar aged deposits
offshore in their area of interest in the North Sea (Quadrant 42 and adjacent areas).
The work was carried out in two phases. Firstly a field-based study of coastal and inland
outcrops in the Berwick area was carried out during February 2007. The Scremerston Formation
is poorly exposed onshore at Berwick, although the overlying succession, equivalent to the basal
part of the offshore Yoredale Formation, is well exposed to the north and south of Berwick.
Sedimentologically the Scremerston Formation and lower part of the overlying Yoredale
Formation appear similar. The main difference appears to be the occurrence of thick marine
limestones in the Yoredale Formation. Hence it is believed that it is valid to include the lower
part of the Yoredale Formation within the study.
Overall the succession represents deposition on a delta plain, transitional with a marine setting.
Periods of delta advance led to the infilling of marine interdistributary bays. Floodplain and
lacustrine facies occur on the delta plain, as well as large braided river channel systems that fed
coarse sediment into the basin. The study found that a variety of reservoir and non-reservoir
lithofacies characterise the succession. The largest sandbodies consist of stacked major channel
systems, up to about 88 ft (27 m) in thickness. These have widths that vary up to about 8 km.
Palaeocurrent analysis of the sandbodies show that they have a consistent trend, with sandbodies
oriented north-south or north-east to south-west; a southerly or south-westerly flow direction is
indicated. The channel fills typically consist of fine- to coarse-grained cross-bedded sandstone,
with a high net-to-gross (typically >0.8). Internal heterogeneity, where present, typically
comprises beds of floodplain mudstones. These are often discontinuous due to erosion by
overlying channels.
The second part of the study involved an analysis of boreholes in the area around and
immediately to the south of Berwick. In total 39 onshore boreholes were databased, irregularly
distributed across an area of approximately 100 km2 (~39 square miles). Borehole stick plots
were drawn, stratigraphic correlations made and sand-to-non-sand maps were constructed. These
sand-to-non-sand maps represent a crude proxy for net-to-gross sand maps and show that, at least
onshore, the succession shows significant lateral variability in sand distribution. Schematic
palaeogeography maps were compiled for 6 sandbodies within the Scremerston and Yoredale
formations. This utilised the borehole and outcrop data