Enigmatic Large-Scale Furrows of Miocene to Pliocene age from the Central North Sea: Current-Scoured Pockmarks?

Ben Kilhams, Adam McArthur, Mads Huuse, Eyita Ita, Adrian Hartley

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

This work presents seismic-stratigraphic, geometric and basinal descriptions for Middle and Late Miocene to Early Pliocene furrows from a deepwater intracratonic setting, based upon regional three-dimensional (3D) seismic data and supporting well information for the UK central North Sea. A range of erosional cross-sectional geometries, typically 1.5 km in width, display a continuum between V- and U-shapes with amalgamation producing complex geometries. Plan-view geometries show an evolution from circular to elongate teardrop and linked/complex structures, whilst seismic infill facies are planar, onlapping, divergent, transparent/opaque or complex. The circular structures (~1 km wide) resemble gas escape pockmarks, especially those in the Cainozoic of the adjacent Danish sector, whilst the linear furrows exhibit varying degrees of elongation and are often asymmetric in the direction of inferred bottom-current flow. A model is presented of initial pockmark crater formation, followed by bottom-current elongation and subsequent amalgamation of these structures to form furrows often over 25 km long. 3D seismic mapping of furrow asymmetry demonstrates a NW–SE trend in the west of the study area, rotating to SW–NE in the east, which supports the idea that an anticlockwise current system existed in the North Sea basin in the Neogene. Well data reveal that these structures contain a mixture of siltstone and carbonate stringers, associated with acoustic disturbance zones possibly indicative of palaeo-gas chimneys. These findings present an important update to the model governing furrow formational mechanisms in deepwater intracratonic settings with, in particular, an origin linked to down-slope pro-Skagerrak delta processes dismissed. This has implications for the velocity models used by the hydrocarbon industry and our understanding of regional pockmark activity during the Neogene in the central North Sea.
Original languageEnglish
Pages (from-to)437-449
Number of pages13
JournalGeo-Marine Letters
Volume31
Issue number5-6
Early online date26 Apr 2011
DOIs
Publication statusPublished - Dec 2011

Fingerprint

pockmark
Pliocene
bottom current
Miocene
geometry
Neogene
Geometry
Elongation
Stringers
Chimneys
infill
siltstone
Gases
gas
crater
Carbonates
asymmetry
seismic data
acoustics
Acoustics

Cite this

Enigmatic Large-Scale Furrows of Miocene to Pliocene age from the Central North Sea : Current-Scoured Pockmarks? / Kilhams, Ben; McArthur, Adam; Huuse, Mads; Ita, Eyita; Hartley, Adrian.

In: Geo-Marine Letters, Vol. 31, No. 5-6, 12.2011, p. 437-449.

Research output: Contribution to journalArticle

Kilhams, Ben ; McArthur, Adam ; Huuse, Mads ; Ita, Eyita ; Hartley, Adrian. / Enigmatic Large-Scale Furrows of Miocene to Pliocene age from the Central North Sea : Current-Scoured Pockmarks?. In: Geo-Marine Letters. 2011 ; Vol. 31, No. 5-6. pp. 437-449.
@article{f498ef9be45e4ee5a3ab3f28b45dad0a,
title = "Enigmatic Large-Scale Furrows of Miocene to Pliocene age from the Central North Sea: Current-Scoured Pockmarks?",
abstract = "This work presents seismic-stratigraphic, geometric and basinal descriptions for Middle and Late Miocene to Early Pliocene furrows from a deepwater intracratonic setting, based upon regional three-dimensional (3D) seismic data and supporting well information for the UK central North Sea. A range of erosional cross-sectional geometries, typically 1.5 km in width, display a continuum between V- and U-shapes with amalgamation producing complex geometries. Plan-view geometries show an evolution from circular to elongate teardrop and linked/complex structures, whilst seismic infill facies are planar, onlapping, divergent, transparent/opaque or complex. The circular structures (~1 km wide) resemble gas escape pockmarks, especially those in the Cainozoic of the adjacent Danish sector, whilst the linear furrows exhibit varying degrees of elongation and are often asymmetric in the direction of inferred bottom-current flow. A model is presented of initial pockmark crater formation, followed by bottom-current elongation and subsequent amalgamation of these structures to form furrows often over 25 km long. 3D seismic mapping of furrow asymmetry demonstrates a NW–SE trend in the west of the study area, rotating to SW–NE in the east, which supports the idea that an anticlockwise current system existed in the North Sea basin in the Neogene. Well data reveal that these structures contain a mixture of siltstone and carbonate stringers, associated with acoustic disturbance zones possibly indicative of palaeo-gas chimneys. These findings present an important update to the model governing furrow formational mechanisms in deepwater intracratonic settings with, in particular, an origin linked to down-slope pro-Skagerrak delta processes dismissed. This has implications for the velocity models used by the hydrocarbon industry and our understanding of regional pockmark activity during the Neogene in the central North Sea.",
author = "Ben Kilhams and Adam McArthur and Mads Huuse and Eyita Ita and Adrian Hartley",
year = "2011",
month = "12",
doi = "10.1007/s00367-011-0235-1",
language = "English",
volume = "31",
pages = "437--449",
journal = "Geo-Marine Letters",
issn = "0276-0460",
publisher = "Springer",
number = "5-6",

}

TY - JOUR

T1 - Enigmatic Large-Scale Furrows of Miocene to Pliocene age from the Central North Sea

T2 - Current-Scoured Pockmarks?

AU - Kilhams, Ben

AU - McArthur, Adam

AU - Huuse, Mads

AU - Ita, Eyita

AU - Hartley, Adrian

PY - 2011/12

Y1 - 2011/12

N2 - This work presents seismic-stratigraphic, geometric and basinal descriptions for Middle and Late Miocene to Early Pliocene furrows from a deepwater intracratonic setting, based upon regional three-dimensional (3D) seismic data and supporting well information for the UK central North Sea. A range of erosional cross-sectional geometries, typically 1.5 km in width, display a continuum between V- and U-shapes with amalgamation producing complex geometries. Plan-view geometries show an evolution from circular to elongate teardrop and linked/complex structures, whilst seismic infill facies are planar, onlapping, divergent, transparent/opaque or complex. The circular structures (~1 km wide) resemble gas escape pockmarks, especially those in the Cainozoic of the adjacent Danish sector, whilst the linear furrows exhibit varying degrees of elongation and are often asymmetric in the direction of inferred bottom-current flow. A model is presented of initial pockmark crater formation, followed by bottom-current elongation and subsequent amalgamation of these structures to form furrows often over 25 km long. 3D seismic mapping of furrow asymmetry demonstrates a NW–SE trend in the west of the study area, rotating to SW–NE in the east, which supports the idea that an anticlockwise current system existed in the North Sea basin in the Neogene. Well data reveal that these structures contain a mixture of siltstone and carbonate stringers, associated with acoustic disturbance zones possibly indicative of palaeo-gas chimneys. These findings present an important update to the model governing furrow formational mechanisms in deepwater intracratonic settings with, in particular, an origin linked to down-slope pro-Skagerrak delta processes dismissed. This has implications for the velocity models used by the hydrocarbon industry and our understanding of regional pockmark activity during the Neogene in the central North Sea.

AB - This work presents seismic-stratigraphic, geometric and basinal descriptions for Middle and Late Miocene to Early Pliocene furrows from a deepwater intracratonic setting, based upon regional three-dimensional (3D) seismic data and supporting well information for the UK central North Sea. A range of erosional cross-sectional geometries, typically 1.5 km in width, display a continuum between V- and U-shapes with amalgamation producing complex geometries. Plan-view geometries show an evolution from circular to elongate teardrop and linked/complex structures, whilst seismic infill facies are planar, onlapping, divergent, transparent/opaque or complex. The circular structures (~1 km wide) resemble gas escape pockmarks, especially those in the Cainozoic of the adjacent Danish sector, whilst the linear furrows exhibit varying degrees of elongation and are often asymmetric in the direction of inferred bottom-current flow. A model is presented of initial pockmark crater formation, followed by bottom-current elongation and subsequent amalgamation of these structures to form furrows often over 25 km long. 3D seismic mapping of furrow asymmetry demonstrates a NW–SE trend in the west of the study area, rotating to SW–NE in the east, which supports the idea that an anticlockwise current system existed in the North Sea basin in the Neogene. Well data reveal that these structures contain a mixture of siltstone and carbonate stringers, associated with acoustic disturbance zones possibly indicative of palaeo-gas chimneys. These findings present an important update to the model governing furrow formational mechanisms in deepwater intracratonic settings with, in particular, an origin linked to down-slope pro-Skagerrak delta processes dismissed. This has implications for the velocity models used by the hydrocarbon industry and our understanding of regional pockmark activity during the Neogene in the central North Sea.

U2 - 10.1007/s00367-011-0235-1

DO - 10.1007/s00367-011-0235-1

M3 - Article

VL - 31

SP - 437

EP - 449

JO - Geo-Marine Letters

JF - Geo-Marine Letters

SN - 0276-0460

IS - 5-6

ER -