Continental breakup between NW Europe and Greenland (~56 Ma) ago was associated with widespread magmatism. Silica undersaturated alkaline porphyritic igneous rocks of a similar age have previously been dredged near the mid-Norwegian coast. These igneous rocks of the Vestbrona Formation have previously been interpreted as either igneous plugs or volcanic flows. New 3D seismic data show that relatively small sill complexes are abundant in the same region. In total, 36 sills with a size of 0.1 to 9 km have been mapped. In addition, ten seismic horizons were interpreted and tied to nearby wells to obtain a robust stratigraphic framework. The sills mainly intrude Cretaceous and Paleocene sequences, however, one sill is also identified in the pre-Cretaceous sequences. The sills locally form erosional remnants on the seabed due to massive uplifting and erosion of the continental margin. Vintage igneous and sedimentary dredge samples have been re-analyzed, including petrography, geochemistry (XRF, XRD), biostratigraphy, and Ar-Ar geochronology. The new Ar-Ar data suggest that the sills are 1-2 Ma older than breakup (ca. 57-58 Ma). Furthermore, the biostratigraphy and petrography of two sediment samples suggest that the samples were collected from near in-situ subcrops and not of an ice rafted origin. The sediment samples are of Danian age, and are strongly metamorphosed, most likely by contact metamorphism resulting from heating during sill emplacement. The newly identified sills have implications for the petroleum prospectivity of the study area including source rock maturation within thermal aureoles and the long term alteration of fluid migration pathways. Page 2 of 50 Interpretation Manuscript, Accepted Pending: For Review Not Production

Continental breakup between northwest Europe and Greenland (approximately 56 Ma) was associated with widespread magmatism. Silica undersaturated alkaline porphyritic igneous rocks of a similar age have previously been dredged near the mid-Norwegian coast. These igneous rocks of the Vestbrona Formation have previously been interpreted as either igneous plugs or volcanic flows. New 3D seismic data indicate that relatively small sill complexes are abundant in the same region. In total, 36 sills with a size of [Formula: see text] have been mapped. In addition, 10 seismic horizons were interpreted and tied to nearby wells to obtain a robust stratigraphic framework. The sills mainly intrude Cretaceous and Paleocene sequences; however, one sill is also identified in the pre-Cretaceous sequences. The sills locally form erosional remnants on the seabed due to massive uplifting and erosion of the continental margin. Vintage igneous and sedimentary dredge samples have been reanalyzed, including petrography, geochemistry (X-ray fluorescence [XRF], X-ray diffraction [XRD]), biostratigraphy, and Ar-Ar geochronology. The new Ar-Ar data suggest that the sills are 1–2 Ma older than breakup (approximately 57–58 Ma). Furthermore, the biostratigraphy and petrography of two sediment samples suggest that the samples were collected from near in situ subcrops and not of an ice rafted origin. The sediment samples are of Danian age and are strongly metamorphosed, most likely by contact metamorphism resulting from heating during sill emplacement. The newly identified sills have implications for the petroleum prospectivity of the study area including source rock maturation within thermal aureoles and the long-term alteration of fluid migration pathways.

Abstract The Helgeland Nappe Complex (HNC), part of the Uppermost Allochthon of the north-central Norwegian Caledonides, originated near the Laurentian margin and was transferred to Baltica during the closure of Iapetus in Late Silurian–Early Devonian time. The islands of Rødøy, Bolvær and Leka, located in the Sauren–Torghatten (S–T) nappe of the HNC, are composed of ultramafic and mafic basement rocks unconformably overlain by metaconglomerates and fine-grained metasedimentary rocks. Geochemical and isotopic characteristics of the basement rocks are consistent with formation in a supra-subduction zone setting. Overlying metasedimentary rocks record an increasing proportion of continental detritus supplied to the basins through time. Precambrian cratonic source regions supplied cobbles and other detritus. This source area may have been located in modern SE Greenland/Labrador or in the Lower Nappe of the HNC. The second alternative best accounts for the short transport distances required by the coarse-grained conglomerates. The maximum age of deposition is constrained by the age of the youngest zircon grain dated at 471±8 Ma. Final sedimentation, nappe thrusting and nappe stacking occurred in rapid succession during c. 480–475 Ma. Supplementary material: Geochemical analyses and Nd isotopic data are available at http://www.geolsoc.org.uk/SUP18654.

The 465 Ma Svarthopen pluton in north-central Norway was emplaced under middle-crustal conditions (similar to 700 MPa) into metasedimentary rocks of the Helgeland Nappe Complex. The pluton is characterized by zones of mingling and mixing of gabbro/diorite with peraluminous, garnet-bearing biotite granite. Variation in bulk-rock Sr and Nd isotope ratios are consistent with simple mixing; however, nonuniform enrichment of Zr and the rare earth elements (REEs) suggests that individual magma batches underwent postmixing fractionation. Hybrid intermediate rocks are characterized by Ca-rich garnet. Such garnet is absent in possible mafic end members, and garnet in felsic end members is Ca poor. Evidently, the ferroan, peraluminous hybrid rocks promoted garnet stability, and we interpret these garnets to be igneous in origin. Garnets in the hybrids have low Zr contents, positive light REE slopes, and flat to negative heavy REE slopes with lower REE abundances than in typical igneous garnet. These trace-element data combined with textural evidence suggest that garnet formed near the solidus, after fractionation of zircon, allanite, and possibly xenotime. The Svarthopen pluton is not unique: similar intermediate rocks with Ca-rich garnets crop out adjacent to three other plutons in the region.Formation of garnet-bearing hybrid rocks in the Svarthopen pluton provides an analog for mixing of peraluminous and ferroan end-member magmas in the deep crust, where such mixing should be widespread, particularly in continental arcs and zones of continental collision. Postmixing fractionation of hybrid magmas could greatly increase the diversity of major-and trace-element abundances yet retain an isotopic signature of mixing. More-over, formation of garnet-rich hybrids could result in lower-crustal rocks dense enough to delaminate from the arc crust.

The British–Irish Palaeogene Igneous Province (BIPIP) is part of the larger North Atlantic Igneous Province and includes the lava fields of Antrim, Mull, and Skye. The Tardree Rhyolite Complex (TRC) in Northern Ireland forms an important stratigraphic unit between the Lower and Upper Basalt Formations of the Antrim Lava Group (ALG). Previous zircon age determinations obtained from the TRC have been used as a standard in zircon fission track studies, but contradict several 40Ar/39Ar sanidine and U–Pb zircon results. We provide new 40Ar/39Ar sanidine and U–Pb CA-TIMS zircon ages which resolve this discrepancy. Two sanidine samples from the Sandy Braes vent and the columnar-jointed dome-forming rhyolites of Tardree Forest yield a weighted mean 40Ar/39Ar age of 61.13±0.42Ma (2σ, internal error). Ten U–Pb CA-TIMS zircon analyses were undertaken, eight of which employed the CA-TIMS approach on both multi-grain fractions and single grains. Six of the CA-TIMS data yield a disequilibrium-corrected weighted mean 206Pb–238U age of 61.32±0.09Ma (2σ). The consistency of the 40Ar/39Ar ages with the CA-TIMS U–Pb zircon age, points to a closed system of both K and Ar since eruption. We propose that the crystallization age of the TRC be taken as 61.32±0.09Ma and that the currently used age of the zircon fission track standard (58.4±0.7Ma) be changed accordingly. This also places the eruption of the TRC in magnetochron C26r, which is consistent with the reversed polarity magnetic remanence observed in the ALG, and supports the conclusion of Ganerød et al. (2010) that the Lower Basalt Formation is older than the Vaigat Formation in Western Greenland. No resolvable zircon inheritance has been detected by the TIMS analyses, consistent with the fact that the temporal and geographic extent of rhyolitic magmatism within this sector of the BIPIP was very limited, and hence was unlikely to provide inherited magmatic zircons from slightly older magmas (antecrysts). Potentially older zircon xenocrysts would be derived from the underlying Caledonian basement (>400Ma) or yet older rocks. These should be easily detectable if the Tardree zircon was to be employed as a U–Pb zircon standard. The paired 40Ar/39Ar and 206Pb–238U results from this study indicate an age of 28.393±0.194Ma for the widely used Fish Canyon sanidine standard and gives further support to the recent calibrations of Kuiper et al. (2008) and Renne et al. (2010).

data indicate a much deeper source than that for the Coastal Batholith, which is considered to be newly accreted lower crust beneath the batholith. Thus, the tectonic environment during the Andean in Peru was dominantly extensional, the magmatism younging to the E. All extensional systems are orthogonal to the Andean trend and relate to rifting associated with spreading systems opening up in the same direction. The relation to subduction is unclear. Tin-tungsten-rare-earth-element mineralisation at Zaaiplaats is hosted by the Bobbejaankop and Lease granites: miarolitic, brick-red alkali feldspar granites which form at high levels within the Lebowa Granite Suite of the Bushveld Complex. Hydrothermal minerals occur as pervasive alteration and within miarolitic cavities. Cassiterite occurs as a cavity filling, as a replacement mineral in tabular, subhorizontal zones and in shallowly-plunging and branching pipes, and as disseminated mineralisation unrelated to fracture systems. The age of mineralisation at Zaaiplaats has been determined by U-Pb dating of cassiterites. Bulk fractions of cassiterite have 206 Pb/ 204 Pb ratios from 30-3,500. Uranium-Pb data for five cassiterites with the highest 206 Pb/ 204 Pb ratios lie on a chord with intersections at 2,099 ±3 Ma and =300 ±20 Ma (MSWD = 0-44). Four samples are from pipe systems and one from cavity fill, suggesting a common age within 6 Ma. The 2,099 ± 3 Ma age is at the upper limit of published 87 Rb/ 86 Sr estimates for emplacement of both the Lebowa Granite Suite (2,046 ± 55 Ma) and the Rustenberg Layered Suite (2,061 ± 27 Ma) and identical within error of an "°Ar/ 39 Ar age of 2,096 ± 12 Ma for the Upper Zone of the Rustenburg Layered Suite. The precise U/Pb dating of cassiterites at Zaaiplaats suggests that mineralisation occurred early in the cooling history of the Bobbejaankop and Lease granites. This is consistent with fluid inclusion and stable isotope data which show that cassiterite and the related brick-red alkali feldspar alteration result from high temperature (>250°C) interaction of magmatic fluids with the cooling granite. The Late Jurassic Grayback Pluton was emplaced in a back-arc environment (Mesozoic remnant arc) behind a contemporaneous Late Jurassic arc. The main stage of the pluton consists of an early unit of reversely zoned tonalite to gabbro that was subsequently intruded by synplutonic noritic and gabbroic magmas. Late-stage tonalitic and granitic dykes typically contain mafic enclaves and zones of hybrid tonalite and quartz diorite. The mafic rocks in the pluton are predominantly calc-alkaline, with magnesian clinopyro-xene, calcic cores in plagioclase, and elemental abundances similar to H 2 O-rich arc basalts. Some mafic samples contain relatively Fe-rich clinopyroxene, lack calcic plagioclase and are composition- ally similar to evolved high-alumina tholeiite. Both groups of mafic rocks lack depletions of HFSE that are typical of arc magmas. Intermediate rocks span a wide range of elemental compositions that can be explained by mixing of calc-alkaline or tholeiitic mafic magmas with tonalitic or granitic magmas, combined with variable degrees of crystal fractionation. Initial "'Sr/^Sr, e Nd , and d'*O range from 0-7028-0-7045, 4-9, and 7-8-14%o, respectively. Late-stage felsic rocks have the highest 87 Sr/ 86 Sr and 6 18 O and display arc-like depletions of HFSE. These data suggest depleted mantle sources for the mafic magmas but a heterogeneous (young remnant arc) crustal source for both the tonalitic and granitic magmas. Mixing of mantle-derived basaltic magmas with isotopi- cally variable crustal melts gave rise to the observed range of compositions. The heterogeneity and compositional range of the Grayback Pluton suggest a complex crustal plumbing system that allowed for injection of batches of mafic magma (derived from at least two types of mantle source rocks), High-temperature foliations are well-developed in all units, and define steeply inward-dipping concentric trajectories defined by the planar alignment of plagioclase, amphibole and biotite, and flattened (oblate) mafic inclusions. Lineations are rare and unsystematic. Foliation is deflected around a large rigid body of mafic/ultramafic country rock, but passes continuously into warm precursor granites, consistent with radial expansion against wall rocks of variable rheology. Thin aplite dykes and small-scale shear zones also have orientations consistent with radial expansion. Mafic inclusions used as strain markers indicate a general trend of decreasing strain toward the centre of the suite. In detail, the strain distribution is very heterogeneous, with decametre wide zones of high strain (9£A r /Zsl2), within broader zones of lower strain (X/Z < 3). The high-strain zones are concentric, laterally discontinuous and characterised by fine-grained dioritic rocks. Compositionally, these rocks resemble undeformed synplutonic mafic dykes. Amphibole-plagioclase thermometry constrains the temperature of deformation to 850-750°C. There is no evidence of a low temperature component, despite evidence of grain-size reduction and recrystallisation in the most deformed diorites. Amphibole in these rocks is characterised by high K contents and low mg# relative to amphibole in undeformed rocks of comparable composition, suggesting interaction of the deforming rocks with evolved interstitial melts. We conclude that the syn-intrusive deformation of the LVS occurred at magmatic temperatures, and propose that strain partitioning reflects local variations in temperature. A-type characterised (comendite) syenites, peraluminous to peralkaline, A-type granites. Sources and conditions of differentiation of A-type granite magmatism changed of Variscan orogenesis, a new replaced of mixed oceanic-continental crust-mantle sources. Primary mantle- derived melts were probably trapped at the crust-mantle boundary where they through high-pressure fractionation to intermediate compositions. Intermediate melts collected in shallow magma chambers, placed at the ductile-brittle transition in the crust, where they evolved through low-pressure fractionation to granitic residual melts. Felsic melts were subsequently less and less contaminated by crustal host rocks. Strong correlations between hydrothermal events, mineralisations and crustal isotope signatures suggest that crustal contribution relates essentially to percolating fluids. complexes, granite centres, carbonatites and kimberlites. The Damaraland zone of anorogenic complexes in northern extends more than 400 km as a well-defined series of NE-oriented lineaments between the Ugab and Khan rivers. The lineament zone coincides with the axis of the Damaran (Pan-African) orogen. Twenty Mesozoic granitic centres have been identified along this zone. Based on evidence from these centres, the marginal zones of granite intrusions are the best places where hydrothermal overprinting of an original magmatic assemblage can be observed. The fluids of magmatic origin causing endogenetic hydrothermal metasomatism by intergranular exchange are derived from the consanguineous crystallisation residua of the host pluton. in multicentred anorogenic granites, that are from later adjacent intrusions whose fluid chemistry may be out of equilibrium with the bulk chemistry of the earlier crystallised pluton. This involves mass transfer of components to form new subsolidus assemblages. amalgamated with inboard terranes, interpreted to represent elements of a behind-arc basin sedimentary sequence, during sinistral transpression. In the outboard terranes, post-kinematic plutonic complexes comprise diorite-to-granite with evidence for local co-mingling of magmas. More extensive mixing between depleted and enriched components is evidenced by the geochemistry and in the isotopic signature of the granitic rocks. By contrast, in the inboard terranes, thickening of the Brioveriari succession during transpressional terrane accretion has resulted in fluid-present anatexis in the St Malo migmatite belt. The St Malo migmatite belt is imbricated by steep, sinistral strike-slip shear zones which contain syn-kinematic granites, suggesting that shear zone deformation and anatexis were broadly coeval. Further inboard, the high-level Mancellian granites are intruded into Brioverian rocks. By analogy with the shear zone system to the W, these granites may have been emplaced into pull-apart structures along a jog in the E-W-trending zone of sinistral shear at the S margin of the belt of transpression. The St Malo migmatites/anatectic granites and the Mancellian granites have like petrographical features, statistically indistinguish- able chemical compositions, and similar Nd isotopic characteristics. These features suggest a common origin for the St Malo migmatites/anatectic granites and the Mancellian granites, which is interpreted to be by anatexis of the immature arc-derived turbidites of the Brioverian succession. Microscopic geometrical and textural characteristics of crystal- lisation sequences, and inferences regarding the rheological properties of crystallising granites, cannot be properly quantified without three-dimensional textural analysis. Three-dimensional analysis utilising serial sectioning and image digitisation has been used to interpret textural development in two granodiorites from the Linga superunit of the Coastal Batholith, Peru. The high level of emplacement of these granodiorites (Atherton 1984) and limited deformation allows excellent preservation of the primary textures. Despite their very similar modal and normative compositions, the two rocks' different textures reflect the variation in nucleation density, growth rate and timing of crystallisation of individual phases. Serial geometries produced for all the major phases identify the individual role that each phase plays during the three main stages of crystallisation, namely: (i) early crystallisation from a melt contai

Large igneous provinces (LIPs) have recently been suggested to originate at the edges of low-velocity zones on the core mantle boundary (Plume Generation Zones). If true, LIPs can potentially be used to constrain paleolongitude in plate tectonic reconstructions. To validate the hypothesis, it is essential to study LIPs of which the paleolongitude can be constrained by other methods, such as hotspot reference frames. An ideal candidate to this end is the early Cenozoic North Atlantic Igneous Province (NAIP). Despite being the largest volcanic unit of the British Tertiary Igneous Province (BTIP, part of the NAIP), the age and paleoposition of the Antrim Lava Group (ALG) in Northern Ireland, which is key to the NAIP as a whole, was hitherto poorly constrained. In this paper, we therefore present an integrated high-resolution paleomagnetic and geochronological study. The ALG is divided into three formations: the Lower Basalt Formation (LBF), Interbasaltic Formation (IBF) and the Upper Basalt Formation (UBF). The IBF is mostly lateritic and encloses the Tardree rhyolite. We offer new age constraints from all three formations using the 40Ar/39Ar method and propose that 62.6 ± 0.3, 61.3 ± 0.3 and 59.6 ± 0.3 Ma (1σ, internal uncertainties) are sound estimates of the age of emplacement of the LBF, Tardree rhyolite (IBF) and UBF, respectively. This constrains the nominal duration of emplacement of the ALG to 3 ± 0.6 Ma (1σ). This 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°N, longitude 167°E (A95 = 6.3; age ∼61 Ma) in the European reference system. This appears consistent with paleomagnetic poles from the rest of the NAIP; both in Europe and Greenland, as well as predictions from modern apparent polar wander paths. The new radiometric ages span magnetochron C26r, C27n and C27r. The normal polarity chron C27n most probably occurred during the IBF hiatus, explaining why no normal polarity remanence was detected in the paleomagnetic investigation. Emplacement of the LBF falls in magnetochron C27r, making this one of the oldest lava sequence in the NAIP; older than the C27n lava pile in Western Greenland. The 60 Ma position of the NAIP in a paleomagnetic reference frame, puts it close to the northern edge of the African large low shear wave velocity anomaly at the core–mantle boundary and therefore in the line with the Plume Generation Zone hypothesis. However, the back-projected Icelandic hotspot, normally considered to have formed the NAIP, is located ∼1500 km north of the latitude at which the NAIP erupted. The northward motion of the north Atlantic lithosphere since the late Cretaceous challenging the existing correlation of the NAIP to the Icelandic hotspot, normally used to explain the observed pre- and syn-breakup North Atlantic magmatism (63–55 Ma), and either an additional plume located further south in the North Atlantic may be invoked to create the NAIP, or the Icelandic hotspot must have undergone a northward motion together with the North Atlantic lithosphere (which according to present mantle flow models seems unlikely).

The Hortavaer intrusive complex, Norway, is a layered igneous complex that was assembled by multiple injections of magmas that ranged from gabbroic through granitic in composition. Layering is defined by intrusive sheets that range from 10 cm to 2 m in thickness. Geopetal structures associated with these sheets indicate that the complex underwent 90 degrees-120 degrees of postsolidification tilting, and subsequent exhumation and erosion have exposed an oblique, 6-km-thick section through the complex. The complex is heterogeneous: at the outcrop scale a range of igneous rock types is exposed and host-rock xenoliths and screens are common. The overall zonation is, from the base upward (west to east), syenite zone (sheets of fine- to coarse-grained syenite), sheeted zone (interlayered syenitic and dioritic sheets), diorite zone (dioritic sheets with thin syenitic intercalations, massive to banded, clinopyroxene-rich cumulate rocks, scant olivine gabbro), eastern zone (dioritic sheets in predominant quartz-bearing monzonite and syenite), and the stratigraphically highest Kvingra alkaline granite. Although magmatic evolution was in batches, individual domains of the pluton and the overall magma evolution of the system display the pervasive influence of assimilation of carbonate-rich rocks, which resulted in the alkaline nature of the evolved magmas. Assimilative reaction between dioritic magmas and calc-silicate rocks resulted in partial melting of the calc-silicates and mixing of the Ca-rich melt into the host magma. Addition of Ca stabilized clinopyroxene (+ plagioclase) at the expense of olivine, which led to precipitation of clinopyroxene-rich cumulates and formation of syenitic residual magmas. Invasion of the calc-silicate rocks by silicate melts resulted in melanocratic garnet + clinopyroxene monzonitic and syenitic endoskarn and magmatic skarn.Because magmatic evolution involved assimilation of calc-silicate rocks and because melt-bearing skarns and clinopyroxene-rich cumulates formed within the complex, magmatic processes responsible for forming the range of rock types in the complex are interpreted to have operated in situ. This interpretation implies that the core of the complex is a zone in which intense reaction of mafic magmas with calc-silicate rocks occurred. Successive emplacement and loading of additional mafic magma onto these zones squeezed the syenitic magmas laterally into tabular intrusions, one zone of which crops out at the exposed base of the complex. Magma loading is also demonstrated by the presence of magmatic foliation parallel to sheet margins in some sheets but the absence of foliation in adjacent sheets.Waning stages of magma evolution were less influenced by assimilation of carbonate-rich rocks. Thus, late-stage magmas displayed silica enrichment and the presence of quartz in the uppermost syenites and monzonites. Ultimately, evolved magmas reached granitic compositions and accumulated in the highest level of the complex. Some granitic (feeder?) dikes extend into the center of the pluton, which indicates that formation of the granitic magmas was piecemeal and occurred in numerous parts of the complex, just as evolution of the less evolved part of the system occurred in batches.

Ophiolite complexes in mountain chains may give supplementary information on the hydration of the oceanic lithosphere to that obtained from dredged and drilled samples from the ocean floor. The ultramafic (mantle) and the layered ultramafic to anorthositic (crustal) sequences of the Cambrian (497 Ma) Leka ophiolite are variably serpentinized and chloritized. Grossular-rodingite (rodingite s.s.) has been found over a c.500 ill long and tens of meters wide zone in the layered, crustal section of the complex and is developed in both pyroxenites and gabbro/anorthosite layers. Shear zones and meter wide fracture zones, where the rock has developed a fracture cleavage, are oriented at high angel to the layering and these zones were the main conduits for transport of fluid and solute between the various lithologies. Some 5-15 cm thick layers of anorthosite (or leucogabbro) have been rodingitized around such a fractures zone, with the development of three distinct metasomatic zones along the plagioclase layer. A central grossular-dominated zone with clinopyroxene, clinozoisite, prehnite, chlorite and minor titanite (rodingite zone) extends for up to 3 in along strike and gives way to a clinozoisite-dominated zone (typically 0.5 m wide) with additional grossular, clinopyroxene and chlorite which is followed outward by a LILE-enriched zone (LILE-zone) with clinozoisite, phlogopite, K-feldspar, plagioclase and preiswerkite. The LILE-zone extends more than 3 m out from the clinozoisite-dominated zone (Clz-zone). Assuming constant volume, the rodingite formed from the plagioclase layer by addition of 20 g of CaO per 100 g of rock. All Na(2)O (c. 2 g) was removed from both rodingite- and Clz-zones. Ti and V increase almost 10x in the rodingite compared to its protolith. K, Ba, Rb and Cs are strongly enriched in the LILE-zone compared to the protolith and Suggest interaction with sea water. The lithologies alternating with the plagioclase layers (clinopyroxenite, wehrlite, websterite and dunite) display textures indicating a number of Ca-releasing (Cpx-->Chl, Cpx-->Srp, Cpx-->Amph) and Ca-consuming (Opx-->Cpx2, Ol-->Cpx2, Cpx1-->Cpx2) reactions. The replacement textures are distributed around fracture and shear zones, with the Ca-releasing reactions in the core and the Ca-consuming reactions in distal parts, forming a metasomatic column out from the fluid pathways. Serpentinization and chloritization of clinopyroxene was the main Ca-source for the rodingitization process. This first description of rodingite in a layered sequence of an ophiolite complex indicates that the hydration of the oceanic lithosphere occurred at various structural levels and was associated with Ca-metasomatism also in places where rodingite s.s. is lacking. The different lithologies exchanged elements through transport on shear and fracture zones. (C) 2007 Elsevier B.V. All rights reserved.

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The paleomagnetic data sets from the British Tertiary Igneous Province (BTIP) have recently been criticized as being unreliable and discordant with data from elsewhere in the North Atlantic Igneous Province (NAIP) [Riisager et al. Earth Planet. Sci. Lett. 201 (2002) 261-276: Riisager et al. Earth Planet. Sci. Lett. 214 (2003) 409-4251. We offer new paleomagnetic data for the extensive lava flow sequence on the Isle of Mull, Scotland, and can confirm the paleomagnetic pole positions emanating from important earlier studies. Our new north paleomagnetic pole position for Eurasia at 59 +/- 0.2 Ma has latitude 73.3 degrees N, longitude 166.2 degrees E (dp/dm=5.2/7.0). A re-evaluation and an inter-comparison of the paleomagnetic database emanating from the NAIP were carried out to test for sub-province consistency. We find a general agreement between the Eurasian part of NAIP (BTIP and Faeroes) and East Greenland data. However a compilation of West Greenland data displays a large and unexplained dispersion. We speculate on if this is related to different sense of block rotation of the Tertiary West Greenland constituents. Combining all data from the NAIP constituents, give a pole position at 75.0 degrees N, 169.9 degrees E (N=25, K=84.3, Ag-95=3.2) in Eurasian reference frame. (C) 2008 Elsevier B.V. All rights reserved.