Permian of the offshore and coastal region of Durham and SE Northumberland

Abstract

Recent bores indicate that the basal Permian (Yellow) Sands of N Durham were deposited largely sub-aerially as dunes 50 m or more high on an almost planar Coal Measures surface. Many of these were inundated by a placid sea and covered by the Marl Slate and Passage Beds. Continued subsidence allowed the succeeding lower Magnesian Limestone to accumulate more rapidly on the slopes of thinly covered dunes possibly with relative relief of 30 m and minor slumping occurred over wide areas. Uplift and tilting led to deepening of the basin to the east and partial erosion of the lower Magnesian Limestone and Marl Slate on land followed by reef development. Anhydrite deposits formed contemporaneously or rather later than the reef. Inshore in N Durham these crystallized discretely from sulphate-rich dolomite muds possibly partly in a sabhka environment with ratio of evaporite to dolomite increasing eastwards towards the basin, ultimately to form continuous, bedded deposits some distance from the present shoreline in N Durham but on shore near Hartlepool. Breccias formed contemporaneously with the evaporites partly due to crystallization pressure and later removal of sulphate.

The Trow Point Bed—a deposit of Upper Permian marine oncoids, peloids and columnar stromatolites in the Zechstein of NE England

“…Oncoids at this stratigraphical position in the English Zechstein sequence have been recognized (Smith & Francis 1967, plate 13A;Magraw 1975Magraw , 1978unpublished National Coal Board records) in the cores of several National Coal Board offshore boreholes (see Fig. 2 for distribution); elsewhere oncoids at a similar stratigraphical position have been reported from cored boreholes in the southern North Sea (Taylor & Colter 1975), northern Germany (Fuchtbauer 1968;Richter-Bernburg 1982) and Poland (Peryt & Peryt 1975 and other authors).…”

Marine Permian of England

“…This attribution was accepted by Smith (in Smith and Francis, 1967), but was shown to be incorrect by Taylor and Fong (1969); these authors discovered calcite concretions in cores of late Permian marine limestones at two different levels separated by evaporites in boreholes in North Yorkshire and disclosed that those at the higher level were associated with the diagnostic biota of the Seaham Formation. Magraw (1975) proposed the term 'Upper Nodular Beds' for concretion-bearing limestones at about the level of the Seaham Formation in a number of partly cored, offshore coal exploration boreholes, but this name has found little favour.…”