Abstract The discovery of Ice Ages is one of the most revolutionary advances ever made in the Earth sciences. In Norway this discovery was made by Danish–Norwegian geoscientist Jens Esmark and his young student Niels Otto Tank, who on a mountain traverse in early September 1823 observed a number of geomorphological features produced by an extant glacier, and compared these to similar features they had previously noted where glaciers today are absent. Seeing a recent moraine pushed up by an extant glacier they suddenly realized that a big ridge of gravel they had earlier seen at sea-level in Southern Norway had to be an ancient moraine, deposited by a big glacier at a time when the climate was substantially colder than today. The brevity of Esmark's account made the precise location of the site of enlightenment remain a mystery for almost two hundred years until it was rediscovered by the author in 2008. This paper describes the crucial site and its lessons.

Abstract The core of the Rodinia supercontinent has long been considered to have consisted of three cratons – Baltica, Laurentia and Amazonia – amalgamated along the late Mesoproterozoic Sveconorwegian, Grenville and Sunsas orogens. In recent years, however, it has become increasingly clear that the metamorphic and magmatic evolution of the Sveconorwegian orogen is inconsistent with a collisional model. Although geological data alone do not rule out proximity to Rodinia, palaeomagnetic data indicate significant latitudinal separation of Baltica and Laurentia during supercontinent assembly. In this contribution, we briefly review two recently proposed and mutually exclusive tectonic models for the Sveconorwegian orogeny and present a compilation of previously published and new chemical and isotopic data. A lack of crustal thickening throughout much of the orogen and few if any changes in lower-crustal sources and melting conditions between 1.3 and 0.9 Ga suggest that the western part of the Sveconorwegian orogeny represents a change from a dominantly extensional to a compressional back-arc regime, but without a significant change in overall tectonic setting. This orogenic evolution is incompatible with amalgamation into Rodinia and suggests that Baltica may have been isolated until the Silurian Caledonian orogeny.

Abstract This chapter describes Lower Jurassic second-order sequences J00 and J10, and their component third-order sequences J1–J6 and J12–J18. Two sequences (J1 and J3) are new, four sequences (J2, J4, J12 and J16) are amended and one sequence (J17) is renamed. A significant unconformity at the base of the J12 sequence (Upper Sinemurian) is present near the base of the Dunlin Group in the North Viking Graben–East Shetland Platform and in the Danish Central Graben, and correlates with an equivalent unconformity around the margins of the London Platform, onshore UK. A marked unconformity at the base of the J16 sequence is recognized in the North Viking Graben and onshore UK, where it is related to structural movements on the Market Weighton High, eastern England. Several levels of carbon enrichment (carbon isotope excursions (CIEs)) and associated geochemical changes tie to J sequences defining maximum flooding surfaces: the Upper Sinemurian CIE equates to the base J6 maximum flooding surface (MFS), the basal Pliensbachian CIE ties to the base J13 MFS, the basal Toarcian CIE relates to the base J17 MFS and the Toarcian Ocean Anoxic Event corresponds with the base J18 MFS.

Abstract This chapter describes uppermost Middle Jurassic–lowermost Cretaceous second-order stratigraphic sequences J40, J50, J60 and J70, and their component third-order sequences J42–J46, J52–J56, J62–J66 and J71–J76. The latest Callovian–Berriasian was an interval of significant tectonism that led to the development of complex stratigraphy and highly variable successions, the elucidation of which is aided by the recognition of the correlation of the J sequences. Marine sedimentation dominated the Callovian–Berriasian interval, with the development of multiple sandstone members comprising reservoir units in many hydrocarbon fields, charged by marine source rocks (e.g. the Kimmeridge Clay Formation). Each of these units is subdivided and correlated by a succession of J sequences. Several sequences are renumbered (e.g. J54, J55, J65 and J66), some sequence definitions are amended or their basal boundaries recalibrated chronostratigraphically (J52, J54, J72, J73, J74 and J76) and new sequence subdivisions are recognized (J64a, J64b, J72a–J72c, J73a and J73b). Significant unconformities are recognized at the bases of the J54, J55, J62, J63, J64, J71 and J73 sequences. The top of J70 (J76) equates to the major ‘Base Cretaceous Unconformity’ seismic sequence boundary.

Abstract The application of sequence stratigraphic concepts and methods augments the efficient development of North Sea hydrocarbon fields with Jurassic reservoirs. In particular, the approach provides enhancements to the development of robust reservoir zonations, more accurate assessments of the extent and continuity of reservoir zones and flow units, clearer identification and prediction of the most productive reservoir intervals, improved understanding of field-wide pressure barriers or baffles to fluid flow, and enhanced reservoir models. In addition, carbon capture and storage (CCS) projects in Jurassic rocks will benefit from the adoption of a sequence stratigraphic approach by enhancing the understanding of storage unit architecture, connectivity and top seals. In this chapter, these applications are discussed with reference to around 20 case studies from the North Sea Basin.

Abstract The application of sequence stratigraphic concepts and methods significantly enhances the evaluation of stratigraphic traps. In this chapter, five examples of, as yet undrilled, potential UK North Sea Jurassic combination stratigraphic traps, from the East Shetland Platform, South Viking Graben, Inner Moray Firth and Central Graben, are discussed and the potential application of sequence stratigraphic methods in their evaluation considered.