ABSTRACT This field guide presents a one-day excursion in Prince George’s County, Maryland, USA, and documents the transition across the Cretaceous-Paleogene boundary by examining sediments from the upper Maastrichtian of the Severn Formation to the Paleocene sediments of the Brightseat and Aquia formations. Emphasis is placed on understanding how differences in depositional character and lithostratigraphy are related to changes in both microfossil and macrofossil assemblages. Particular attention is given to the difficulty in distinguishing Upper Cretaceous sediments from lower Paleocene sediments in the field, a problem that has traditionally led to misrepresentation of the distribution and thickness of these units and their correlation on a regional scale. Regarding the Late Cretaceous geology, the guide presents information on the lithology and microfossil biostratigraphy of the Severn Formation, which consists predominantly of silty quartz sand, with less than 5% clay. These sediments are placed in calcareous nannofossil Zone CC25a, suggesting an early late Maastrichtian age. Low abundances of planktic foraminifera combined with sedimentological evidence suggest deposition most likely occurred in a middle neritic environment. Macrofossils in the outcrops along the field trip consist primarily of fragmented bivalve mollusk and cephalopod shell material. A hiatus of ~5 m.y. separates the Cretaceous sediments from the overlying Paleocene deposits. As for the Paleocene geology, the guide presents information on the Brightseat and Aquia formations. The Brightseat represents early Danian age deposition and consists of clayey, silty sand at the base that grades upward into a silty sand. Glauconite is present at <5% throughout the formation in outcrop. Sediments of the Brightseat Formation are placed in calcareous nannofossil Zone NP3. Macrofossils are limited to small bivalve fragments that are scattered throughout. A hiatus representing ~3 m.y. separates the Brightseat from the overlying Aquia Formation, which is Selandian to Thanetian in age and consists of a glauconite-rich (~10%–20%), silty sand with common to abundant macrofossils, including both fragmented and complete gastropods and bivalves.

Abstract The Burghley Field is a Paleocene oil field located in Block 16/22 on the UK Continental Shelf about 8.5 km NE of the Balmoral Field, in a water depth of c. 143 m. Burghley produces undersaturated oil from sandstones of the Maureen Formation. It comprises a low relief four-way dip-closed structure located on the SE end of the Fladen Ground Spur. The field was discovered in 2005 by well 16/22-7. Overall nine well penetrations were drilled prior to the commitment to develop the field. The Burghley Field was brought on-stream in October 2010 as a single subsea horizontal well development tied back to the Balmoral floating production vessel. The current estimate for oil in place is c. 20 MMbbl for the entire field, with approximately 12 MMbbl in the core area where the development well is located. The expected ultimate recovery is approximately 5.65 MMbbl.

Abstract The Kraken and Kraken North fields lie in the UK Continental Shelf Block 9/2b on the East Shetland Platform. Hydrocarbons are stratigraphically trapped within Heimdal Sandstone Member of the Lista Formation. The fields lie at around 3900 ft true vertical; depth subsea and the oil is heavy (13–15°API) and viscous. The field is developed via a waterflood scheme with long horizontal production and injection wells, alternating across the field. To date, 21 development wells have been drilled, with further wells planned. Reservoir quality is extremely good with porosity around 36% and permeabilities in the range of 2–10 D. The field is produced via the Armada Kraken floating production storage and offloading vessel. Developed stock tank oil originally in place is in the region of 400 MMbbl, with further currently undeveloped resources to the west of the field.

Abstract Wintershall Noordzee BV recently discovered and appraised two Chalk oil fields (Rembrandt and Vermeer) in the Dutch North Sea with wells F17-10, F17-11, F17-12 and F17-13x. Extensive core material is available, and biostratigraphical analysis plus sedimentological evaluation results are presented here. Integration of these data with detailed 3D seismic interpretation results in interesting conclusions on the tectonic inversion of the Dutch Central Graben. It can be determined that the main inversion event is the Sub-Hercynian Phase, after which an island was formed in the Chalk sea during the Campanian and Maastrichtian. Around this island, erosion products can be found in the Chalk intervals. These sediments are time and facies comparable to the Vaals Formation in the south of The Netherlands, adjacent to the inverted Roer Valley Graben. Maastrichtian sediments are seen to onlap onto the island, decreasing it in size and influence as a sediment source. It is proposed that the Laramide inversion phase in the Dutch Central Graben is a period of non-deposition and, possibly, this is also the case for most of the other Dutch inverted basins.

Abstract This Special Report comprehensively describes the stratigraphy and correlation of the Tertiary (Paleogene-Neogene) rocks of NW Europe and the adjacent Atlantic Ocean and is the summation of fifty years of research on Tertiary sediments by Chris King. His book is essential reading for all geologists who deal with Tertiary rocks across NW Europe, including those in the petroleum industry and geotechnical services as well as academic stratigraphers and palaeontologists. Introductory sections on chronostratigraphy, biostratigraphy and other methods of dating and correlation are followed by a regional summary of Tertiary sedimentary basins and their framework and an introduction to Tertiary igneous rocks. The third and largest segment comprises the regional stratigraphic summaries. Regions covered are the North Sea Basin, on shore areas of southern England and the eastern English Channel area, the North Atlantic margins (including non-marine basins in the Irish Sea and elsewhere) and the Paleogene igneous rocks of Scotland.

The record of dinosaurs over the last 10 m.y. of the Cretaceous, as well as surrounding the Cretaceous-Paleogene boundary, helps to define extinction scenarios. Although Late Cretaceous dinosaur fossils occur on all present-day continents, only in North America do we find a terrestrial vertebrate fossil record spanning the Cretaceous-Paleogene boundary, although promising work may yield comparable records in South America, India, China, and Europe. For the present then, the North American record represents the proxy for our knowledge of dinosaur extinction. Over the last 10 m.y. of the Cretaceous (late Campanian to late Maastrichtian) in the northern part of the western interior of North America, the number of nonavian dinosaur species dropped from 49 to 25, almost a 50% reduction, even though a 16% greater extent of fossil-bearing exposures record the last dinosaurs in the latest Cretaceous in the western interior. Important, but less-well-exposed, nonavian-dinosaur–bearing units suggest this drop occurred around, or at least commenced by, the Campanian-Maastrichtian boundary. These losses began during climatic fluctuations, occurring during and possibly in part caused by the last major regressive cycle of the Cretaceous, which also reduced the expanse of the low coastal plains inhabited by nonavian dinosaurs. The pulse of Deccan Trap emplacement that began some time later in the latest Cretaceous was also likely a major driver of climatic change. As for the dinosaur record near the Cretaceous-Paleogene boundary, even the best-known records from North America remain enigmatic and open to interpretation. Newer studies suggest some decline in at least relative abundance approaching the Cretaceous-Paleogene boundary, but the cause (or causes) for the final extinction (if it was the case) of non-avian dinosaurs remains unresolved, although the Chicxulub impact undoubtedly played a major role.