scholarly journals Eocene tarpons from the North Sea region, Denmark and UK

2015 ◽  
Author(s):  
Maria E. C. Leal ◽  
Bo P. Schultz ◽  
Henrik Madsen ◽  
Chiara Villa ◽  
Niels Lynnerup ◽  
...  
Keyword(s):  
North Sea ◽  
Late Jurassic ◽  
Late Eocene ◽  
Biological Anthropology ◽  
Early Eocene ◽  
The North ◽  
Lower Jaw ◽  
The North Sea ◽  
London Clay ◽  
Cretaceous Period

There are very few tarpons (family Megalopidae) and other elopiforms (fam. Elopidae) recorded in the Tertiary. The records are mainly from the Eocene, and more abundant in the ‘North Sea Region’ in Early Eocene, as for instance the large Danish forms. They are also found in late Early Eocene in London Clay, in Late Eocene in Caucasia, and in Miocene of SE-Asia, although none were described from the famous Bolca fauna (early Mid Eocene). However, there is a large, still undescribed ‘tarpon-like’ fish in the Bolca Museum (obs. MECL & NB 2014). There are even fewer described from the long Cretaceous period, 4-5? genera, including the large Paraelops from Romualdo Formation, Araripe Basin, NE-Brazil, and a large undescribed megalopid from Tlayua, Pueblo, Mexico, both ‘Mid Cretaceous’. The oldest elopiforms are from Late Jurassic Solnhofen Limestone. The large Danish ‘tarpons’ come from ‘cementstones’ in Fur Formation (earliest Eocene, ca. 55 m.y.), and here we report an almost complete specimen which is ca. 110 cm long; however, big isolated scales found in this formation indicate fishes at least twice as big (comparable in size with the living Tarpon atlanticus - over 2½ m). This specimen has a heavy skull lacking the lower jaw, and is preserved in 3-D. It was split in the midline and acid prepared, being then CT-scanned in Aarhus and reconstructed in the Laboratory of Biological Anthropology, Copenhagen University to attempt precise, detailed comparisons with modern skulls and with the 3-D skulls preserved in concretions from the London Clay.

scholarly journals Eocene tarpons from the North Sea region, Denmark and UK

2015 ◽  
Author(s):  
Maria E. C. Leal ◽  
Bo P. Schultz ◽  
Henrik Madsen ◽  
Chiara Villa ◽  
Niels Lynnerup ◽  
...  
Keyword(s):  
North Sea ◽  
Late Jurassic ◽  
Late Eocene ◽  
Biological Anthropology ◽  
Early Eocene ◽  
The North ◽  
Lower Jaw ◽  
The North Sea ◽  
London Clay ◽  
Cretaceous Period

There are very few tarpons (family Megalopidae) and other elopiforms (fam. Elopidae) recorded in the Tertiary. The records are mainly from the Eocene, and more abundant in the ‘North Sea Region’ in Early Eocene, as for instance the large Danish forms. They are also found in late Early Eocene in London Clay, in Late Eocene in Caucasia, and in Miocene of SE-Asia, although none were described from the famous Bolca fauna (early Mid Eocene). However, there is a large, still undescribed ‘tarpon-like’ fish in the Bolca Museum (obs. MECL & NB 2014). There are even fewer described from the long Cretaceous period, 4-5? genera, including the large Paraelops from Romualdo Formation, Araripe Basin, NE-Brazil, and a large undescribed megalopid from Tlayua, Pueblo, Mexico, both ‘Mid Cretaceous’. The oldest elopiforms are from Late Jurassic Solnhofen Limestone. The large Danish ‘tarpons’ come from ‘cementstones’ in Fur Formation (earliest Eocene, ca. 55 m.y.), and here we report an almost complete specimen which is ca. 110 cm long; however, big isolated scales found in this formation indicate fishes at least twice as big (comparable in size with the living Tarpon atlanticus - over 2½ m). This specimen has a heavy skull lacking the lower jaw, and is preserved in 3-D. It was split in the midline and acid prepared, being then CT-scanned in Aarhus and reconstructed in the Laboratory of Biological Anthropology, Copenhagen University to attempt precise, detailed comparisons with modern skulls and with the 3-D skulls preserved in concretions from the London Clay.

Late Palaeozoic to Early Cenozoic geological evolution of the northwestern German North Sea (Entenschnabel): New results and insights

2014 ◽  
Vol 93 (4) ◽  
pp. 147-174 ◽  
Author(s):  
Jashar Arfai ◽  
Fabian Jähne ◽  
Rüdiger Lutz ◽  
Dieter Franke ◽  
Christoph Gaedicke ◽  
...  
Keyword(s):  
North Sea ◽  
Lower Cretaceous ◽  
Late Jurassic ◽  
Structural Element ◽  
The North ◽  
Sedimentary Evolution ◽  
Basin Subsidence ◽  
The North Sea ◽  
Thickness Variations ◽  
Zechstein Salt

AbstractThe results of a detailed seismic mapping campaign of 13 horizons in the northwestern German North Sea, covering Late Permian to Palaeogene sedimentary successions, are presented. Based on the interpretation of four 3D and two 2D seismic surveys, thickness and depth maps of prominent stratigraphic units were constructed. These maps provide an overview of key structural elements, the sedimentation and erosion, and give insights into the evolution of the German Central Graben. The base of the Zechstein Group reaches a maximum depth of 7800 m within the German Central Graben. Lateral thickness variations in the Zechstein reflect the extensive mobilisation of Zechstein salt. Complex rift-related structures, with the Central Graben as the main structural element, were found not later than the Early Triassic. Up to 3000-m thick Triassic sediments are preserved in the eastern German Central Graben of which 1800 m consist of Keuper sediments. The Lower Buntsandstein unit shows increasing thicknesses towards the southeastern study area, likely related to distinct lateral subsidence. As a consequence of uplift of the North Sea Dome, Middle Jurassic sediments were eroded in large parts of the northwestern German North Sea and are only preserved in the German Central Graben. The NNW–SSE oriented John Basin is another important structural element, which shows maximum subsidence during the Late Jurassic. In most parts of the study area Lower Cretaceous sediments are absent due to either erosion or non-deposition. Lower Cretaceous deposits are preserved in the Outer Rough Basin in the northwest and within the German Central Graben. Upper Cretaceous sediments are found at depths between 1500 and 3600 m, reaching a maximum thickness of approximately 1600 m on the Schillgrund High. Contraction and inversion of pre-existing Mesozoic faults during the Late Cretaceous is distinct at the Schillgrund Fault, i.e. the eastern border fault of the Central Graben. The Palaeogene is predominantly a period of strong basin subsidence. Within 37 Myrs, up to 1400 m of Palaeogene sediments were deposited in the northwesternmost part of the study area. Detailed mapping of salt structures enables a reconstruction of halokinetic movements over time and a deciphering of the influence of the Zechstein salt on the sedimentary evolution during the Mesozoic and Cenozoic. Increasing sediment thicknesses in rim-synclines indicate that most of the salt structures in the German Central Graben had their main growth phase during the Late Jurassic.

scholarly journals III.—On the Structure of the Valleys of the Blackwater and the Crough, and of the East Essex Gravel, and on the Relation of this Gravel to the Denudation of the Weald

1866 ◽  
Vol 3 (26) ◽  
pp. 348-354 ◽  
Author(s):  
Searles V. Wood
Keyword(s):  
North Sea ◽  
Glacial Period ◽  
The South ◽  
Northern Boundary ◽  
The North ◽  
Complete Order ◽  
The North Sea ◽  
Boulder Clay ◽  
London Clay

In a paper in this Magazine, upon the structure of the Thames Valley, I endeavoured to show that instead of being, as had been asserted, a valley of similar structure to those of the Somme and Seine, and containing deposits of nearly similar order and age, the valley in which the Thames gravel was deposited possessed no outlet to what is now the North Sea, being divided from it by a range of high gravelless country; and that, in lieu of such an outlet, the valley opened, in more than one part, over what is now the bare Chalk country forming the northern boundary of the Valley of the Weald. I also endeavoured to show that all the deposits of the Thames Valley, except the peat and marsh clay, belonged to several successive stages, marking the gradual denudation of the Boulderclay, the lower Bagshot, the London Clay, and the subjacent Tertiaries, which had, at the end of the Glacial period, spread over the south-east of England in a complete order of succession: the sea into which this valley discharged occupying, what is now, the Chalk country of the Counties of Kent, Surrey, Sussex, and Hampshire, inclusive of the interval subsequently scooped out to form the Valley of the Weald: so that, not only was the latter valley newer than that of the Thames, and of the most recent of the Thames Valley deposits, except the peat and marsh clay, but that these deposits in themselves marked a long descent in time from that comparatively remote period of the Boulder-clay.

Lithology and subsidence in the North Sea

1982 ◽  
Vol 305 (1489) ◽  
pp. 85-99 ◽  
Keyword(s):  
North Sea ◽  
Late Jurassic ◽  
Late Carboniferous ◽  
Delta Front ◽  
Submarine Fans ◽  
The North ◽  
Late Tertiary ◽  
Moray Firth ◽  
Deltaic Sedimentation ◽  
The North Sea

The North Sea sedimentary basin has developed on the northwestern margin of the European tectonic plate and contains an almost continuous record of epeirogenic marine and deltaic sedimentation from Carboniferous to Recent times. The subsidence required to accommodate the pile of sediment deposited, which in places exceeds 12 km, has been brought about at various times and in various places by differing geodynamical processes. As a result the types of sedimentary rocks deposited vary widely both in time and space, but the nature of the mechanism is reflected in the sedimentary type deposited. The following broad generalizations can be made. The late Carboniferous was a period of deltaic sedimentation during which eustatic changes in sea level or local variations in subsidence rates are reflected in the typical Coal Measures swamp deposits. Late Carboniferous - early Permian times saw the silting up of this basin, and in an arid climate aeolian sands were deposited grading laterally to sabkha shales and evaporites. The Permian culminated in a series of widespread marine incursions during which repetitive evaporites were deposited. Triassic times were marked by a period of major rifting and the deposition of thick sequences of continental elastics in the north, while widespread marine sedimentation persisted in southern areas. Jurassic times saw the re-establishment of marine to deltaic deposition in a series of basins possibly controlled in their distribution by the Triassic fault systems. Late Jurassic deposits were laid down in a sea whose bathymetry reflected the structure of the underlying horsts and grabens inherited from Triassic times, and towards the close of the Jurassic the bottom waters at least of this sea become increasingly stagnant. Sands deposited during the late Jurassic were deposited as near-shore marine bars, beach sands, and proximal and distal submarine fans. Triassic to early Cretaceous deposition was concentrated in the areas now occupied by the main grabens of the North Sea, i.e. the Viking, Central and Moray - Witch Ground grabens. Subsequent deposition in late Cretaceous to Tertiary times took place in a more widely subsiding area, resulting in progressive onlap onto the surrounding basin margins. Deposition within this broadly subsiding and relatively unfaulted basin is characterized by chalky limestones in southern areas, giving way laterally to shales and minor sands to the north. During early Tertiary times a large delta was formed in the area beneath the present Moray Firth, and from this delta a supply of sand was fed into submarine fans to the northeast and southeast of the delta front. Late Tertiary deposition is largely represented by a monotonous sequence of marine shales.

scholarly journals New Paleocene bird fossils from the North Sea Basin in Belgium and France

2019 ◽  
Vol 22 (1-2) ◽  
pp. 35-46 ◽  
Author(s):  
Gerald MAYR ◽  
Thierry SMITH
Keyword(s):  
North America ◽  
North Sea ◽  
Early Eocene ◽  
Fossil Assemblage ◽  
The North ◽  
The North Sea ◽  
Dispersal Events ◽  
Early Cenozoic

We describe new avian remains from Paleocene localities of Belgium and France. Four bones from the early to middle Selandian of Maret (Belgium) are among the earliest Cenozoic avian remains known from Europe and include the oldest temporally well constrained European records of the Gastornithidae, as well as tentative records of the palaeognathous Lithornithidae and the Ralloidea. A more comprehensive fossil assemblage from the middle Thanetian of Templeuve (France) contains multiple bones of the Lithornithidae as well as a record of the Pelagornithidae. Specimens from the latest Thanetian of Rivecourt-Petit Pâtis (France) are tentatively assigned to the Ralloidea and Leptosomiformes (cf. Plesiocathartes). Because of the fragmentary nature of the fossils, the taxonomic identity of a number of other specimens remains uncertain. We note, however, that Paleocene avifaunas of Europe and North America appear to have had different compositions and only a few taxa, such as the palaeognathous Lithornithidae, are known from both continents. This suggests that the very similar early Eocene avifaunas of Europe and North America are the result of early Cenozoic dispersal events.

Stable isotope and biotic evolution in the North Sea during the early Eocene: the Albæk Hoved section, Denmark

1996 ◽  
Vol 101 (1) ◽  
pp. 275-306 ◽  
Author(s):  
B. Schmitz ◽  
C. Heilmann-Clausen ◽  
C. King ◽  
E. Steurbaut ◽  
F. P. Andreasson ◽  
...  
Keyword(s):  
Stable Isotope ◽  
North Sea ◽  
Early Eocene ◽  
The North ◽  
The North Sea

scholarly journals Early Cretaceous

1982 ◽  
Vol 8 ◽  
pp. 45-49
Author(s):  
Jens Morgen Hansen ◽  
Arne Buch
Keyword(s):  
North Sea ◽  
Early Cretaceous ◽  
Late Cretaceous ◽  
Late Jurassic ◽  
Significant Feature ◽  
Marine Clay ◽  
The North ◽  
Marine Sand ◽  
The North Sea ◽  
Early Late

The Early Cretaceous sea primarily covered the same basinal regions as the Late Jurassic sea but, late in the Early Cretaceous the sea also covered Late Jurassic land masses. During Early Cretaceous time the topography of the North Sea region became gradually buried. The following major transgression comprises the transition Early/Late Cretaceous. At the Jurassic/ Cretaceous transition, the Late Cimmerian unconformity is a significant feature (fig. 24), known from large parts of the North Sea region. The subsequent transgression and sedimentation of marine clay (the Valhall Formation), and marine sand (the LC-1 Unit), started late in Late Jurassic. Therefore, the formations described in the present chapter also comprise sediments of Late Jurassic age. Thicknesses of the Lower Cretaceous sediments are given in fig. 15.

Quantitative analysis of net-transgressive shoreline trajectories and stratigraphic architectures: mid-to-late Jurassic of the North Sea rift basin

2009 ◽  
Vol 21 (5) ◽  
pp. 528-558 ◽  
Author(s):  
Gary J. Hampson ◽  
Peter J. Sixsmith ◽  
Rachel L. Kieft ◽  
Christopher A. -L. Jackson ◽  
Howard D. Johnson
Keyword(s):  
Quantitative Analysis ◽  
North Sea ◽  
Late Jurassic ◽  
Rift Basin ◽  
The North ◽  
The North Sea

The Balmoral, Glamis and Stirling Fields, Block 16/21, UK Central North Sea

2003 ◽  
Vol 20 (1) ◽  
pp. 395-413 ◽  
Author(s):  
M. Gambaro ◽  
M. Currie
Keyword(s):  
North Sea ◽  
Oil Recovery ◽  
Late Jurassic ◽  
Horizontal Well ◽  
Water Injection ◽  
Final Phase ◽  
The North ◽  
The North Sea ◽  
Central North Sea ◽  
Regional Aquifer

AbstractThe Balmoral Oilfield is a mature asset in its final phase of production. Associated with the Balmoral development have been the less significant Glamis and Stirling Fields. Each field is different from the perspective of geology and many other issues. Balmoral is a typical Paleocene oilfield with good water drive from a large regional aquifer. Interestingly this was not recognized at the start of the development when water injection facilities were commissioned. Glamis is a smaller field of Late Jurassic age containing somewhat lighter oil than Balmoral. Water injection has been necessary to maximize recovery in this field. Stirling is one of the few fields in the North Sea to produce commercially from the naturally fractured Devonian Sandstone. This field is developed by a single horizontal well.Balmoral oil recovery has significantly exceeded original expectations, whilst Glamis and Stirling have produced as much as expected.

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