The record of early Tertiary N Atlantic volcanism in sediments of the North Sea Basin

Knox, R. W. O’B.; Morton, Andrew

doi:10.1144/gsl.sp.1988.039.01.36

Cited by 81 publications

(115 citation statements)

References 22 publications

Supporting

Mentioning

112

Contrasting

Order By: Relevance

“…A compilation of the new radiometric ages presented here, published NAVP lava ages, and fossil ages of ash layers in sediments in the North Sea (Knox and Morton, 1988;Morton et al, 1988) indicate that the bulk of the province is the product of two distinct pulses of magmatism, one occurring prior to 60 Ma and the other beginning around 57 Ma (Fig. 7).…”

Section: North Atlantic Volcanismmentioning

confidence: 74%

“…. Compilation of new radiometric ages presented in this paper and published ages from West Greenland (Larsen et al, 1992), East Greenland (Noble et al, 1988;Hansen et al, 1993;Upton et al, 1995), northwest Britain (Dagley and Mussett, 1986;Mussett, 1986), the Vøring Plateau (Boulter and Manum, 1989), and North Sea sediments (Knox and Morton, 1988;Morton et al, 1988). We cannot discount older ages in the eastern Atlantic SDRS because the lower lavas were not sampled.…”

Section: Discussionmentioning

confidence: 92%

See 1 more Smart Citation

40 Ar- 39 Ar ages of lavas from the southeast Greenland Margin, ODP Leg 152, and the Rockall Plateau, DSDP Leg 81

Sinton¹,

Duncan²

1998

Proceedings of the Ocean Drilling Program

View full text Add to dashboard Cite

ABSTRACT40 Ar incremental heating experiments were performed on volcanic rocks recovered by drilling during Ocean Drilling Program Leg 152, southeast Greenland Margin (63°N), and Deep Sea Drilling Project Leg 81, southwest Rockall Plateau (56°N). Both of these legs drilled into thick sections of submerged lava flows, known as seaward-dipping reflector sequences, that are part of the Tertiary North Atlantic Volcanic Province (NAVP). Results show that subaerial volcanism began at the southeast Greenland Margin as early as 61−62 Ma with the eruption of continentally contaminated lavas. After an apparent hiatus, volcanism continued with the subaerial eruption of noncontaminated, mid-ocean-ridge basalt (MORB) -like lavas. A sill or flow was emplaced at 52 Ma into the sediments overlying the basement lavas at the most seaward site (918). The MORB-like lavas of the Rockall Plateau gave poor results, although the data suggest that they erupted at 57−58 Ma and may be contemporaneous with the compositionally similar oceanic lavas of Leg 152.Compiled ages from the NAVP indicate that most of the lavas were erupted in two distinct magmatic episodes. The first occurred prior to 60 Ma with volcanism at the southeast Greenland Margin, in West Greenland, and the northwest British Isles. This early stage of widespread volcanism most likely records the arrival of the Iceland mantle plume. The second phase of magmatism began about 57 Ma with voluminous basaltic eruptions centralized along the eventual line of continental separation. Magmatism at this stage was associated with continental breakup and asthenospheric upwelling with probable thermal input from the mantle plume.

show abstract

Section: North Atlantic Volcanismmentioning

confidence: 74%

Section: Discussionmentioning

confidence: 92%

40 Ar- 39 Ar ages of lavas from the southeast Greenland Margin, ODP Leg 152, and the Rockall Plateau, DSDP Leg 81

Sinton¹,

Duncan²

1998

Proceedings of the Ocean Drilling Program

View full text Add to dashboard Cite

show abstract

“…The discrepancy is related either to the uncertain lower series field behavior or to poor precision of the polarity timescale. We therefore tentatively correlate the lower series with pyroclastic subphase 2a and the Sele Formation (Knox and Morton, 1988), but note that the composition and thickness of the sediment layer between the two volcanic series might reflect a hiatus at this level (Fig. 8).…”

Section: Timingmentioning

confidence: 83%

“…Depth conversion based on velocities from Mutter et al, (1984), Eldholm and Mutter (1986), and (Berggren et al, 1985). B: Phases of pyroclastic activity in the Faeroe-Greenland province and equivalent central North Sea formations (Knox and Morton, 1988). C: Seismic horizons EE (top of the time-transgressive lower Eocene flow basalts, TP (lowermost Eocene tuff marker) and C (base Tertiary) (Skogseid and Eldholm, this volume).…”

Section: Timingmentioning

confidence: 99%

See 1 more Smart Citation

Evolution of the Vøring Volcanic Margin

Eldholm¹,

Thiede²,

Taylor³

1989

Proceedings of the Ocean Drilling Program

136

107

View full text Add to dashboard Cite

ODP Sites 642 and 643 recovered a succession of rocks which have greatly improved the understanding of how the Cenozoic volcanic Wring Margin evolved, particularly by providing important constraints on the series of events that occurred during the initial opening of the Norwegian-Greenland Sea. The more than 900 m of igneous rocks and interbedded sediments drilled at Site 642 constitute two distinct, strikingly different volcanic series. The upper series, composed of transitional mid-oceanic tholeiitic lava flows and thin interbedded volcaniclastic sediments confirmed the seaward-dipping reflectors to be a terrestrially constructed extrusive complex. The lower series, probably extending for several hundred meters below the bottom of the hole, consists of another flow complex of dacitic composition, some dikes and thicker interbedded sediments, partially continentally derived. We suggest that the margin evolved by crustal extension in the Paleocene accompanied by uplift and a progressively more intense invasion of dikes and sills in the rift zone. Just prior to breakup, magma from shallow crustal melts produced the lower series. The upper series was constructed during an intense, rapidly waning, volcanic surge of subaerial accretion of oceanic magma following breakup in middle of Chron 24.2R. The surge is characterized by a much increased rate of magma production and high spreading rate. The upper series cover both newly formed oceanic crust and large areas of the adjacent thinned continental crust. The dipping wedge was formed by subsidence due to loading and thermal contraction, possibly amplified by a tectonic force. When the surge had abated, the injection center quickly subsided and normal oceanic crust was formed. Our interpretation is that the continent/ocean boundary occurs at the seaward termination of reflector K, which separates the two volcanic series. However, a region of strongly intruded transitional crust is inferred in 30-to 50-km wide zones on either side of the Vdring Plateau Escarpment.The Wring Margin experienced crustal uplift and extension prior to breakup, restricted to a Tertiary marginal basin west of the present shelf edge. The initial volcanic surge and shallow extrusion level are related to a higher than normal temperature at the base of the lithosphere, inducing partial melting combined with opening in previously thinned crust. The commonly described non-extensional nature of this margin is only an apparent phenomenon. Except for the outer basin, extension by dike injection coupled with high strength of the thin, pre-opening crust in the Vdring Basin precluded the formation of a faulted rift unconformity. We believe these observations have relevance for volcanic margins elsewhere, but infer that seaward-dipping reflectors can form in many environments.The Wring Plateau marginal high and other similar features in the North Atlantic are an integrated part of the North Atlantic Volcanic Province, which extends 2000 km longitudinally. Compared to the central, transverse, part of ...

show abstract

Incipient mantle plume evolution: Constraints from ancient landscapes buried beneath the North Sea

Quay

Watson

Jackson

2017

Geochem Geophys Geosyst

View full text Add to dashboard Cite

Geological observations that constrain the history of mantle convection are sparse despite its importance in determining vertical and horizontal plate motions, plate rheology, and magmatism. We use a suite of geological and geophysical observations from the northern North Sea to constrain evolution of the incipient Paleocene-Eocene Icelandic plume. Well data and a three-dimensional seismic survey are used to reconstruct a 58-55 Ma landscape now buried 1.5 km beneath the seabed in the Bressay region. Geochemical analyses of cuttings from wells that intersect the landscape indicate the presence of angiosperm debris. These observations, combined with presence of coarse clastic material, interpreted beach ridges, and a large dendritic drainage network, indicate that this landscape formed subaerially. Longitudinal profiles of paleo-rivers were extracted and inverted for an uplift rate history, indicating three distinct phases of uplift and total cumulative uplift of 350 m. Dinoflagellate cysts in the surrounding marine stratigraphy indicate that this terrestrial landscape formed in <3 Ma and was rapidly drowned. This uplift history is similar to that of a slightly older buried landscape in the Faeroe-Shetland basin 400 km to the west. These records of vertical motion are consistent with pulses of anomalously hot asthenosphere spreading out from the incipient Icelandic plume. Using simple isostatic calculations, we estimate that the maximum thermal anomaly beneath Bressay was 50-1008C. Our observations suggest that a thermal anomaly departed the Icelandic plume around 57.4 6 2.2 Ma at the latest and travelled with a velocity > 150 km/Ma.

show abstract

The record of early Tertiary N Atlantic volcanism in sediments of the North Sea Basin

Cited by 81 publications

References 22 publications

40 Ar- 39 Ar ages of lavas from the southeast Greenland Margin, ODP Leg 152, and the Rockall Plateau, DSDP Leg 81

40 Ar- 39 Ar ages of lavas from the southeast Greenland Margin, ODP Leg 152, and the Rockall Plateau, DSDP Leg 81

Evolution of the Vøring Volcanic Margin

Incipient mantle plume evolution: Constraints from ancient landscapes buried beneath the North Sea

Contact Info

Product

Resources

About