@article{fdi:010049576,
  title = {{T}he {N}orth {A}tlantic {I}gneous {P}rovince reconstructed and its relation to the {P}lume {G}eneration {Z}one : the {A}ntrim {L}ava {G}roup revisited},
  author = {{G}anerod, {M}. and {S}methurst, {M}. {A}. and {T}orsvik, {T}. {H}. and {P}restvik, {T}. and {R}ousse, {S}onia and {M}c{K}enna, {C}. and van {H}insbergen, {D}. {J}. {J}. and {H}endriks, {B}. {W}. {H}.},
  editor = {},
  language = {{ENG}},
  abstract = {{P}>{L}arge igneous provinces ({LIP}s) have recently been suggested to originate at the edges of low-velocity zones on the core mantle boundary ({P}lume {G}eneration {Z}ones). {I}f true, {LIP}s can potentially be used to constrain paleolongitude in plate tectonic reconstructions. {T}o validate the hypothesis, it is essential to study {LIP}s of which the paleolongitude can be constrained by other methods, such as hotspot reference frames. {A}n ideal candidate to this end is the early {C}enozoic {N}orth {A}tlantic {I}gneous {P}rovince ({NAIP}). {D}espite being the largest volcanic unit of the {B}ritish {T}ertiary {I}gneous {P}rovince ({BTIP}, part of the {NAIP}), the age and paleoposition of the {A}ntrim {L}ava {G}roup ({ALG}) in {N}orthern {I}reland, which is key to the {NAIP} as a whole, was hitherto poorly constrained. {I}n this paper, we therefore present an integrated high-resolution paleomagnetic and geochronological study. {T}he {ALG} is divided into three formations: the {L}ower {B}asalt {F}ormation ({LBF}), {I}nterbasaltic {F}ormation ({IBF}) and the {U}pper {B}asalt {F}ormation ({UBF}). {T}he {IBF} is mostly lateritic and encloses the {T}ardree rhyolite. {W}e offer new age constraints from all three formations using the 40{A}r/39{A}r method and propose that 62.6 +/- 0.3, 61.3 +/- 0.3 and 59.6 +/- 0.3 {M}a (1 {S}igma, internal uncertainties) are sound estimates of the age of emplacement of the {LBF}, {T}ardree rhyolite ({IBF}) and {UBF}, respectively. {T}his constrains the nominal duration of emplacement of the {ALG} to 3 +/- 0.6 {M}a (1 {S}igma). {T}his reevaluation of the magnetic signature in the {ALG} revealed reverse polarity remanence in all three formations and an overall paleomagnetic north pole at latitude 78.9 degrees {N}, longitude 167 degrees {E} ({A}95 = 6.3; age similar to 61 {M}a) in the {E}uropean reference system. {T}his appears consistent with paleomagnetic poles from the rest of the {NAIP}; both in {E}urope and {G}reenland, as well as predictions from modern apparent polar wander paths. {T}he new radiometric ages span magnetochron {C}26r, {C}27n and {C}27r. {T}he normal polarity chron {C}27n most probably occurred during the {IBF} hiatus, explaining why no normal polarity remanence was detected in the paleomagnetic investigation. {E}mplacement of the {LBF} falls in magnetochron {C}27r, making this one of the oldest lava sequence in the {NAIP}; older than the {C}27n lava pile in {W}estern {G}reenland. {T}he 60 {M}a position of the {NAIP} in a paleomagnetic reference frame, puts it close to the northern edge of the {A}frican large low shear wave velocity anomaly at the core-mantle boundary and therefore in the line with the {P}lume {G}eneration {Z}one hypothesis. {H}owever, the back-projected {I}celandic hotspot, normally considered to have formed the {NAIP}, is located similar to 1500 km north of the latitude at which the {NAIP} erupted. {T}he northward motion of the north {A}tlantic lithosphere since the late {C}retaceous challenging the existing correlation of the {NAIP} to the {I}celandic hotspot, normally used to explain the observed pre- and syn-breakup {N}orth {A}tlantic magmatism (63-55 {M}a), and either an additional plume located further south in the {N}orth {A}tlantic may be invoked to create the {NAIP}, or the {I}celandic hotspot must have undergone a northward motion together with the {N}orth {A}tlantic lithosphere (which according to present mantle flow models seems unlikely).},
  keywords = {{M}agnetostratigraphy ; {P}alaeomagnetism applied to geologic processes ; {H}otspots ; {L}arge igneous provinces},
  booktitle = {},
  journal = {{G}eophysical {J}ournal {I}nternational},
  volume = {182},
  numero = {1},
  pages = {183--202},
  ISSN = {0956-540{X}},
  year = {2010},
  DOI = {10.1111/j.1365-246{X}.2010.04620.x},
  URL = {https://www.documentation.ird.fr/hor/fdi:010049576},
}