In this contribution we present novel radiometric 40Ar/39Ar ages representing a number of basaltic sills/lavas of the Faroe Islands, which themselves form part of the North Atlantic Igneous Province. Measured ages are utilised in an attempt to assess the local igneous history, where the new ages are contrasted against those of other local rocks of known ages as well as against those of comparable/neighbouring North Atlantic igneous regions. The novel ages presented in this contribution allow us to put new constraints on the timing of late stage magmatic activity and associated crustal extension of this part of the North Atlantic area. In this research we present new ages as young as ~50.5 Ma for some of the smallest Faroese sills and demonstrate that the larger and oldest local sills, grouped into the low-TiO2 Streymoy/Kvívík sills and the high-TiO2 Eysturoy/Sundini sills respectively (~55.5 Ma), likely formed immediately subsequent to the formation of the uppermost parts of the Enni Formation, which itself represent the latest stages of local surface magmatism at ~55.8 Ma. Gradually decreasing sill volumes coupled with successively younger ages point to systematic decrease of local igneous activity with increasing distances to active contemporaneous local rifting zones. Comparable scenarios recorded for other parts of the North Atlantic Igneous Province support our inferences regarding the nature of late-stage magmatic activity at some distances from zones of active seafloor-spreading. Comparisons between ages of Faroese igneous products versus those of e. g. central E Greenland point to a somewhat diachronous evolution pattern within this part of the North Atlantic Igneous Province subsequent to ~57.5 Ma. The lithosphere-asthenosphere boundary is commonly thought to be critical for the formation of basaltic magmas. Accordingly, the close spatial and temporal associations between many high-TiO2 and low-TiO2 Faroese rock suites are interpreted in the context of a regional version of this boundary.
| Published in | Earth Sciences (Volume 12, Issue 5) |
| DOI | 10.11648/j.earth.20231205.12 |
| Page(s) | 121-139 |
| Creative Commons |
This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited. |
| Copyright |
Copyright © The Author(s), 2023. Published by Science Publishing Group |
Timing Nature Magmatism, North Atlantic Igneous Province, Faroe Islands, Flood Basalts, Sill Intrusions, 40Ar/39Ar Geochronology, Petrogenetic Interpretations
| [1] | Saunders, A. D., Fitton, J. G., Kerr, A. C., Norry, M. J. and Kent, R. W. (1997). The North Atlantic Igneous Province: Geophys. Monogr. 100, 45-93. |
| [2] | Saunders, A. D. (2016). Two LIPs and two Earth-system crises: the impact of the North Atlantic Igneous Province and the Siberian Traps on the Earth-surface carbon cycle: Geol. Mag. 153 (2), 201-222. doi: 10.1017/S0016756815000175. |
| [3] | Wilkinson, C. M., Ganerød, M., Hendriks, B. W. H. and Eide, E. A. (2016). Compilation and appraisal of geochronological data from the North Atlantic Igneous Province (NAIP): Geol. Soc. London Spec. Publ. 447. http://doi.org/10.1144/SP447.10. |
| [4] | Hansen, J., Jerram, D. A., McCaffrey, K. J. W. and Passey, S. R. (2009). The onset of the North Atlantic Igneous Province in a rifting perspective: Geol. Mag. 146 (3), 309-325. https://doi.org/10.1017/S0016756809006347. |
| [5] | Hansen J. (2011). Petrogenetic Evolution, Geometries and Intrusive Styles of the Early Cenozoic Saucer-Shaped Sills of the Faroe Islands: Doctoral thesis, Durham University, http://etheses.dur.ac.uk/3631/. |
| [6] | Á Horni, J. A., Hopper, J. R., Blischke, A., Geisler, W. H., Stewart, M., McDermott, K. H., Judge, M., Erlendsson, Ö. and Árting, U. E. (2017) Regional distribution of volcanism within the North Atlantic Igneous Province: Geol. Soc. London, Spec. Publ. 447, 105-125. http://doi.org/10.1144/SP447.18. |
| [7] | Meyer, R., Van Wijk, J. and Gernigon, L. (2007). The North Atlantic Igneous Province: A review of models for its formation: Geol. Soc. Am. Spec. Pap. 430, 525-52. |
| [8] | Millet, J. M., Hole, M. J., Jolley, D. W., Passey, S. R. and Rosetti, L. (2020). Transient mantle cooling linked to regional volcanic shut-down and early rifting in the North Atlantic Igneous Province: Bull. Volcan. 82: 61, 27. https://doi.org/10.1007/s00445-020-01401-8. |
| [9] | Storey, M., Duncan, R. A. and Tegner, C. (2007). Timing and duration of volcanism in the North Atlantic Igneous Province: implications for geodynamics and links to the Iceland hotspot: Chem. Geol. 241, 264-281. doi: 10.1016/j.chemgeo.2007.01.016. |
| [10] | Hansen, J., Jerram, D. A., McCaffrey, K. J. W. and Passey, S. R. (2011). Early Cenozoic saucer-shaped sills of the Faroe Islands: an example of intrusive styles in basaltic lava piles, J. Geol. Soc. London 168 (1), 159-178. |
| [11] | Hansen, J., Davidson, J. P., Jerram, D. A., Ottley, C. J. and Widdowson, M. (2019). Contrasting TiO2 compositions in Early Cenozoic mafic sills of the Faroe Islands: an example of basalt formation from distinct melting regimes: Earth Sci. 8 (5), 235-267. http://www.sciencepublishinggroup.com/j/earth doi: 10.11648/j.earth.20190805.11. |
| [12] | Hansen, J. (2020). Transgressive sills and lateral lava flows: on the visual observation of igneous sheets in rugged mountainous terrains and the optical illusion factor: Earth Sci. 9 (5), 164-177. doi: 10.11648/j.earth.20200905.13. |
| [13] | Passey, S. R. and Jolley, D. W. (2009). A revised lithostratigraphic nomenclature for the Palaeogene Faroe Islands Basalt group, NE Atlantic Ocean: Earth Environm. Sci. Trans. Royal Soc. Edinb. 99 (3-4), 127-158. https://doi.org/10.1017/S1755691009008044. |
| [14] | Hansen J. (2015). A numerical approach to sill emplacement in isotropic media: Do saucer-shaped sills represent ‘natural’ intrusive tendencies in the shallow crust?: Tectonophys. 664, 125–138. http://dx.doi.org/10.1016/j.tecto.2015.09.006. |
| [15] | Tarling, D. H. and Gale, N. H. (1968). Isotopic dating and palaeomagnetic polarity in the Faeroe Islands: Nature, 218, 1043-1044. |
| [16] | Waagstein, R. (1988). Structure, composition and age of the Faeroe basalt plateau: Geol. Soc. London Spec. Publ. 39, 225-238. https://doi.org/10.1144/GSL.SP.1988.039.01.21. |
| [17] | Abrahamsen, N. (2006). Palaeomagnetic results from the Lopra-1/1A re-entry well, Faroe Islands: Geol. Surv. Denm. and Greenl. Bull. 9, 51-65. |
| [18] | Waagstein, R., Guise, P. and Rex, D. (2002). K/Ar and 40Ar/39Ar whole-rock dating of zeolite facies metamorphosed flood basalts: the upper Paleocene basalts of the Faroe Islands, NE Atlantic: Geol. Soc. London Spec. Publ. 197, 219-252. https://doi.org/10.1144/GSL.SP.2002.197.01.09. |
| [19] | Hansen, J. and Ganerød, M. (2023b). Sampling and evaluation of basaltic rocks of the Faroe Islands: Details on material used in geochronological 40Ar/39Ar dating of local rocks”, Mendeley Data, V1, https://data.mendeley.com/datasets/2y29tsw7nh/1 |
| [20] | Holm, P. M., Hald, N. and Waagstein, R. (2001). Geochemical and Pb-Sr-Nd isotopic evidence for separate hot depleted and Iceland plume mantle sources for the Paleogene basalts of the Faroe Islands: Chem. Geol. 178, 95-125. https://doi.org/10.1016/S0009-2541(01)00260-1. |
| [21] | McDougall, I. and Harrison, T. M. (1999). Geochronology and Thermochronology by the 40Ar/39Ar Method: Oxford University Press, pp. 269. |
| [22] | Renne, P. R., Mundil, R., Balco, G., Min, K. and Ludwig, K. R. (2010). Joint determination of 40K decay constants and 40Ar∗/40K for the Fish Canyon sanidine standard, and improved accuracy for 40Ar/39Ar geochronology: Geochim. Cosmochim. Acta, 74 (18), 5349-5367. https://doi.org/10.1016/j.gca.2010.06.017. |
| [23] | Lee, J-Y,. Marti, K., Severinghaus, J. P, Kawamura, K., Yoo, H-S., Lee, J. B. and Kim, J. S. (2006). A redetermination of the isotopic abundances of atmospheric Ar: Geochim. Cosmochim, Acta, 70, 4507-4512. doi: 10.1016/j.gca.2006.06.1563. |
| [24] | Hansen, J. and Ganerød, M. (2023a). Geochronology of the Faroe Islands: A case study on 40Ar/39Ar dating of local basaltic sills and selected lavas: Mendeley Data, V5, https://data.mendeley.com/datasets/87gtjjh5gb/5 |
| [25] | Tegner, C., Brooks, C. K., Duncan, R. A., Heister, L. E. and Bernstein, S. (2008). 40Ar/39Ar ages of intrusions in East Greenland: Rift-to-drift transition over the Iceland hotspot: Lithos, 101, 480-500. https://doi.org/10.1016/j.lithos.2007.09.001. |
| [26] | Ganerød, M., Smethurst, M. A., Torsvik, T. H., Prestvik, T., Rousse, S., McKenna, C., Van Hinsbergen, D. J. J. and Hendriks, B. W. H. (2010). The North Atlantic Igneous Province reconstructed and its relation to the Plume Generation Zone: the Antrim Lava Group revisited: Geophys. J. Internat. 182 (1), 183-202. http://doi.org/10.1111/j.1365-246X.2010.04620.x. |
| [27] | Svensen, H., Planke, S. and Corfu, F. (2010). Zircon dating ties the NE Atlantic sill emplacement to initial Eocene global warming: J. Geol. Soc. London, 167, 433-436. doi.1144/0016-76492009-125. |
| [28] | Brooks, C. K. (2011). The East Greenland rifted volcanic margin: Geol. Surv, Greenl. Denm. Bull. 24, pp 97. |
| [29] | Larsen, L. M., Pedersen, A. K., Tegner, C., Duncan, R. A., Hald, N. and Larsen, J. G. (2016). Age of Tertiary volcanic rocks On the West Greenland Continental Margin: volcanic evolution and event correlation to other parts of the North Atlantic Igneous Province: Geol. Mag. 153, 487-511. doi.10.1017/S0016756815000515. |
| [30] | Peace, A. L., Foulger, G. R., Schiffer, C. and McCaffrey, K. J. W. (2017). Evolution of Labrador Sea–Baffin Bay: Plate or Plume Processes?: Geosci. Can. 44, 91-102. https://doi.org/10.12789/geocanj.2017.44.120. |
| [31] | Franke, D., Klitzke, P., Barckhausen, U., Berglar, K., Berndt, C., Damm, V., Dannowski, A., Ehrhart, A., Engels, M., Funck, T., Geissler, W., Schnabel, M., Thorwart, M. and Trinhammer. P. (2019). Polyphase magmatism during the formation of the northern East Greenland continental margin: Tectonics, 38 (4), 2961-3982. doi.10.1029/2019TC005552. |
| [32] | Gernigon, L., Franke, D., Geoffroy, L., Schiffer, C., Foulger, G. R. and Stoker, M. (2020). Crustal fragmentation, magmatism, and the diachronous opening of the Norwegian-Greenland Sea: Earth-Sci. Rev. 206 (102839), 1-37. https://doi.org/10.1016/j.earscirev.2019.04.011. |
| [33] | Schiffer, C., Doré, A. G., Foulger, G. R., Franke, D., Geoffroy, L., Gernigon, L., Holdsworth, B., Kuznir, N., Lundin, E., McCaffrey, K. J. W., Peace, A. L., Petersen, D., Phillips, T. B., Dtephenson, R., Stoker, M. and Welford, J. K. (2020). Structural inheritance in the North Atlantic: Earth-Sci. Rev. 206 (102975). https://doi.org/10.1016/j.earscirev.2019.102975. |
| [34] | Archer, S. G., Bergman, S. C., Iliffe, J., Murphy, C. M. and Thornton, M. (2005). Palaeogene igneous rocks reveal new insights into the geodynamic evolution and petroleum potential of the Rockall Trough, NE Atlantic Margin: Basin Res. 17, 171-201. doi: 10.1111/j.1365.2117.2005.00260.x. |
| [35] | Niu, Y. (2020). On the cause of continental breakup: A simple analysis on driving mechanisms of plate tectonics and mantle plumes: J. As. Earth Sci. 194, 104367. http://doi.org/10.1016/j.jseaes.2020.104367. |
| [36] | Niu, Y. (2021). Lithosphere thickness controls the extent of mantle melting, depth of melt extraction and basalt compositions in all tectonic settings on Earth – A review and new perspectives: Earth-Sci. Rev. 217 (103614), 25. https://doi.org/10.1016/j.earscirev.2021.103614. |
| [37] | McDonough, W. F. and Sun, S.-s., 1995, The composition of the Earth: Chem. Geol. 120, 223-253. |
| [38] | Renne, P. R., Swisher, C. C., Deino, A. L., Karner, D. B., Owens, T. L. and DePaolo, D. J. (1998). Intercalibration of standards, absolute ages and uncertainties in 40Ar/39Ar dating: Chem. Geol. 145, 117-152. |
| [39] | Kuiper, K. F., Deino, A., Hilgen, F. J., Krijgsman, W., Renne, P. R. and Wijbrans, J. R. (2008). Synchronizing rock clocks of Earth history: Science 320 (5875), 500-504. https://doi.org/10.1126/science.1154339. |
| [40] | Min, K., Mundil, R., Renne, P. R., and Ludwig, K. R. (2000). A test for systematic errors in 40Ar/39Ar geochronology through comparison with U/Pb analysis of a 1.1-Ga rhyolite: Geochim. Cosmochim. Acta, 64 (1), 73-98. https://doi.org/10.1016/S0016-7037(99)00204-5. |
| [41] | Richardson, K. R., Smallwood, J. R., White, R. S., Snyder, D. B. and Maguire, P. K. H. (1998). Crustal structure beneath the Faroe Islands and the Faroe-Iceland Ridge: Tectonophys, 300, 159-180. https://doi.org/10.1016/S0040-1951(98)00239-X. |
| [42] | Darbyshire, F. A., Dahl-Jensen, T., Larsen, T. B., Voss, P. H. and Joyal, G. (2018). Crust and uppermost-mantle structure of Greenland and the Northwest Atlantic from Rayleigh wave group velocity tomography: Geophys. J. Internat. 212, 1546-1569. doi: 10.1093/gji/ggx479. |
| [43] | Walker, F., Schofield, N., Millet, J., Jolley, D., Hole, M. and Stewart, M. (2020). Paleogene volcanic rocks in the northern Faroe–Shetland Basin and Møre Marginal High: understanding lava field stratigraphy: Geol. Soc. London Spec. Publ. 495. https://doi.org/10.1144/SP495-2019-13. |
| [44] | Søager, N. and Holm, P. M. (2009). Extended correlation of the Paleogene Faroe Islands and East Greenland plateau basalts: Lithos, 107, 205-215. https://doi.org/10.1016/j.lithos.2008.10.002. |
| [45] | Millett, J. M., Hole, M. J., Jolley, D. W. and Passey, S. R. (2017). Geochemical stratigraphy and correlation within Large Igneous Provinces: The final preserved stages of the Faroe Islands Basalt Group: Lithos, 286-287, 1-15. https://doi.org/10.1016/j.lithos.2017.05.011. |
| [46] | Wotzlaw, J-F., Bindeman, I. N., Schaltegger, U., Brooks, C. K. and Naslund, H. R. (2012). High-resolution insights into episodes of crystallization, hydrothermal alteration and remelting in the Skaergaard intrusive complex: Earth Plan. Sci. Lett. 255-256, 199-212. DOI: 10.1016/J.EPSL.2012.08.043. |
| [47] | Naumenko-Dèzes, M. O., Nägler, T. F., Mezger, K. and Villa, M. (2018). Constraining the 40K decay constant with 87Rb-87Sr – 40K-40Ca chronometer intercomparison: Geochim. Cosmochim. Acta, 220, 235-247. https://doi.org/10.1016/j.gca.2017.09.041 |
| [48] | Harrison, J. C., Mayr, U., McNeil, D. H., Sweet, A. R., McIntyre, D. J., Eberle, J. J., Harington, C. R., Chalmers, J. A., Dam, G. and Nøhr-Hansen, H. (1999). Correlation of Cenozoic sequences of the Canadian Arctic region and Greenland; implications for the tectonic history of northern North America: Bull. Can. Petrol. Geol. 47 (3), 223-254. |
| [49] | Larsen, L. M., Pedersen, A. K., Sørensen, E. V., Watt, W. S. and Duncan, R. A. (2013). Stratigraphy and age of the Eocene Igtertivâ Formation basalts, alkaline pebbles and sediments of the Kap Dalton Group in the graben at Kap Dalton, East Greenland: ©2013 by: Bull. Geol. Soc. Denm. 61, 1–18. ISSN 2245-7070. Baker, M. B. and Stolper, E. M. (1994). Determining the composition of high-pressure mantle melts using diamond aggregates: Geochim. Cocmochim. Acta, 58 (13), 2811-2827. |
| [50] | Thórarinsson, S. B., Holm, P. M., Tappe, S., Heaman, L. M. and Prægel, N-O. (2016). U–Pb geochronology of the Eocene Kærven intrusive complex, East Greenland: constraints on the Iceland hotspot track during the rift-to-drift transition: Geol. Mag. 153 (1), 128-142. DOI: https://doi.org/10.1017/S0016756815000448. |
| [51] | Walker, G. P. L. (1971). Compound and simple lava flows and flood basalts: Bull. Volcanol. 35, 579-590. https://doi.org/10.1007/BF02596829. |
| [52] | Harris, A. J. L. and Rowland, S. K. (2009) Effusion rate controls on lava flow length and the role of heat loss: A review. From: THORDARSON, T., SELF, S., LARSEN, G., ROWLAND, S. K. & HOSKULDSSON, A. (eds) Studies in Volcanology: The Legacy of George Walker: Special Publications of IAVCEI, 2, 33– 51. Geol. Soc. London, 1750-8207. https://doi.org/10.1144/IAVCEl002.3. |
| [53] | Rychert, C. A., Harmon, N., Constable, S. and Wang, S. (2020). The Nature of the Lithosphere‐Asthenosphere Boundary: Journ. Geophys. Res. Solid Earth, 125, e2018JB016462, 39. DOI: 10.1029/2018jb016463. |
| [54] | Kinzler, R. J. (1997). Melting of mantle peridotite at pressures approaching the spinel to garnet transition: Application to mid-ocean ridge basalt petrogenesis: J. Geophys. Res. 102 (B1), 853-874. https://doi.org/10.1029/96JB00988. |
| [55] | Collinet, M., Medard, E., Charlier, B., Auwera, J. V. and Grove, T. L. (2015). Melting of the primitive martian mantle at 0.5–2.2 GPa and the origin of basalts and alkaline rocks on Mars: Earth Sci. Plan. Lett. 427, 83-94. https://doi.org/10.1016/j.epsl.2015.06.056. |
| [56] | Yaxley, G. M. (2000). Experimental study of the phase and melting relations of homogeneous basalt + peridotite mixtures and implications for the petrogenesis of flood basalts: Contrib. Mineral. Petrol. 139, 326-338. |
| [57] | Kogiso, T., Hirose, K. and Takahashi, E. (1998). Melting experiments on homogeneous mixtures of peridotite and basalt: application to the genesis of ocean island basalts: Earth Plan. Sci. Lett. 162, 45-61. |
| [58] | Baker, M. B. and Stolper, E. M. (1994). determining the composition of high-pressure mantle melts using diamond aggregates. Geochim. Cocmochim. Acta, 58 (13), 2811-2827. |
| [59] | Ulmer, P. (2001). Partial melting inj the mantle wedge the role of H2O in the genesis of mantle-derived ’arc-related’ magmas: Phys. Earth Plan. Int. 127, 215-232. https://doi.org/10.1016/S0031-9201(01)00229-1. |
| [60] | Falloon, T. J., Green, D. H., Danyushevsky, L. V. and McNeill, A. W. (2008). The composition of near-solidus partial melts of fertile peridotite at 1 and 1.5 GPa: implications for the petrogenesis of MORB: J. Petrol. 49 (4), 591-613. |
| [61] | Hirose, K. and Kushiro, I. (1993). Partial melting of dry peridotites at high pressures: Determination of compositions of melts segregated from peridotite using aggregates of diamond: Earth Plan. Sci. Lett. 114, 477-489. |
| [62] | Hirose, K. and Kawamoto, T. (1995). Hydrous partial melting of lherzolite at 1 GPa: The effect of H2O on the genesis of basaltic magmas: Earth Plan. Sci. Lett. 133, 463-473. |
| [63] | Green, D. H. and Falloon, T. J. (2005). Primary magmas at mid-ocean ridges, ”hotspots,” and other intraplate settings: Constraints on mantle potential temperature. in Foulger GR, Natland JH, Presnall DC, Anderson DL, eds., Plates, plumes, and paradigms: Geol. Soc. Am. Spec. Pap. 388, 217-247. https://doi.org/10.1130/0-8137-2388-4.217. |
| [64] | Krein, S. B., Behn, M. D. and Grove, T. L. (2020). Origins of major element, trace element and isotope garnet signatures in mid-ocean ridge basalts: J. Geophys. Res. Solid Earth, 125 (12), pp. 33. https://doi.org/10.1029/2020JB019612. |
| [65] | Patkó, L., Liptai, N., Aradi, L. E., Klébesz, R., Sendula, E., Bodnar, R. J., Kovács, I. J., Hidas, K., Cesare, B., Novák, A., Trásy, B. and Szabó, C. (2020). Metasomatism-induced wehrlite formation in the upper mantlebeneath the Nógrád-Gömör Volcanic Field (Northern Pannonian Basin): Evidence from xenoliths: Geosci. Front. 11 (3), 943-964. https://doi.org/10.1016/j.gsf.2019.09.012. |
| [66] | Puziewicz, J., Matusiak-Malek, M., Ntaflos, T., Grégoire, M., Kaszmarek, M-A., Aulbach, S., Ziobro, M. and Kukula, A. (2020). Three major types of subcontinental lithospheric mantle beneath the Variscan Orogen in Europe: Lithos, 362-363, 105467. https://doi.org/10.1016/j.lithos.2020.105467. |
| [67] | Foulger, G. R., Doré, T., Emeleus, C. H., Franke, D., Geoffroy, L., Gernigon, L., Hey, R., Holdsworth, R. E., Hole, M., Höskuldsson, Á., Julian, B., Kusznir, N., Martinez, F., McCaffrey, K. J. W., Natland, J. H., Peace, A. L., Petersen, K,. Stephenson, R. and Stoker, M. (2020). The Iceland Microcontinent and a continental Greenland-Iceland-Faroe Ridge: Earth-Sci. Rev. 206, 102926. https://doi.org/10.1016/j.earscirev.2019.102926. |
| [68] | Søager, N. and Holm, P. M. (2011). Changing compositions of the Iceland plume; Isotopic and elemental constraints from the Paleogene Faroe flood basalts: Chem. Geol. 280, 297-313. https://doi.org/10.1016/j.chemgeo.2010.11.017. |
| [69] | Lesnov, F. P., Koz’menko, O. A., Nikolaeva, I. V. and Palesskii, S. V. (2009). Residence of incompatible trace elements in a large spinel lherzolite xenolith from alkali basalt of Shavaryn Tsaram-1 paleovolcano (western Mongolia), Russ. Geol. Geophys. 50 (12), 1063-1072. https://doi.org/10.1016/j.rgg.2009.11.005. |
| [70] | Rollinson, H. (1993). Using geochemical data: evaluation, presentation, interpretation, Longman, 352. https://doi.org/10.4324/9781315845548. |
APA Style
Jógvan Hansen, Morgan Ganerød. (2023). On the Timing and Nature of Magmatism in the North Atlantic Igneous Province: New Implications from Basaltic Rocks of the Faroe Islands. Earth Sciences, 12(5), 121-139. https://doi.org/10.11648/j.earth.20231205.12
ACS Style
Jógvan Hansen; Morgan Ganerød. On the Timing and Nature of Magmatism in the North Atlantic Igneous Province: New Implications from Basaltic Rocks of the Faroe Islands. Earth Sci. 2023, 12(5), 121-139. doi: 10.11648/j.earth.20231205.12
AMA Style
Jógvan Hansen, Morgan Ganerød. On the Timing and Nature of Magmatism in the North Atlantic Igneous Province: New Implications from Basaltic Rocks of the Faroe Islands. Earth Sci. 2023;12(5):121-139. doi: 10.11648/j.earth.20231205.12
Share This Article
Twitter
Linked In
Facebook
Copy
Download@article{10.11648/j.earth.20231205.12,
author = {Jógvan Hansen and Morgan Ganerød},
title = {On the Timing and Nature of Magmatism in the North Atlantic Igneous Province: New Implications from Basaltic Rocks of the Faroe Islands},
journal = {Earth Sciences},
volume = {12},
number = {5},
pages = {121-139},
doi = {10.11648/j.earth.20231205.12},
url = {https://doi.org/10.11648/j.earth.20231205.12},
eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.earth.20231205.12},
abstract = {In this contribution we present novel radiometric 40Ar/39Ar ages representing a number of basaltic sills/lavas of the Faroe Islands, which themselves form part of the North Atlantic Igneous Province. Measured ages are utilised in an attempt to assess the local igneous history, where the new ages are contrasted against those of other local rocks of known ages as well as against those of comparable/neighbouring North Atlantic igneous regions. The novel ages presented in this contribution allow us to put new constraints on the timing of late stage magmatic activity and associated crustal extension of this part of the North Atlantic area. In this research we present new ages as young as ~50.5 Ma for some of the smallest Faroese sills and demonstrate that the larger and oldest local sills, grouped into the low-TiO2 Streymoy/Kvívík sills and the high-TiO2 Eysturoy/Sundini sills respectively (~55.5 Ma), likely formed immediately subsequent to the formation of the uppermost parts of the Enni Formation, which itself represent the latest stages of local surface magmatism at ~55.8 Ma. Gradually decreasing sill volumes coupled with successively younger ages point to systematic decrease of local igneous activity with increasing distances to active contemporaneous local rifting zones. Comparable scenarios recorded for other parts of the North Atlantic Igneous Province support our inferences regarding the nature of late-stage magmatic activity at some distances from zones of active seafloor-spreading. Comparisons between ages of Faroese igneous products versus those of e. g. central E Greenland point to a somewhat diachronous evolution pattern within this part of the North Atlantic Igneous Province subsequent to ~57.5 Ma. The lithosphere-asthenosphere boundary is commonly thought to be critical for the formation of basaltic magmas. Accordingly, the close spatial and temporal associations between many high-TiO2 and low-TiO2 Faroese rock suites are interpreted in the context of a regional version of this boundary.},
year = {2023}
}
TY - JOUR T1 - On the Timing and Nature of Magmatism in the North Atlantic Igneous Province: New Implications from Basaltic Rocks of the Faroe Islands AU - Jógvan Hansen AU - Morgan Ganerød Y1 - 2023/09/27 PY - 2023 N1 - https://doi.org/10.11648/j.earth.20231205.12 DO - 10.11648/j.earth.20231205.12 T2 - Earth Sciences JF - Earth Sciences JO - Earth Sciences SP - 121 EP - 139 PB - Science Publishing Group SN - 2328-5982 UR - https://doi.org/10.11648/j.earth.20231205.12 AB - In this contribution we present novel radiometric 40Ar/39Ar ages representing a number of basaltic sills/lavas of the Faroe Islands, which themselves form part of the North Atlantic Igneous Province. Measured ages are utilised in an attempt to assess the local igneous history, where the new ages are contrasted against those of other local rocks of known ages as well as against those of comparable/neighbouring North Atlantic igneous regions. The novel ages presented in this contribution allow us to put new constraints on the timing of late stage magmatic activity and associated crustal extension of this part of the North Atlantic area. In this research we present new ages as young as ~50.5 Ma for some of the smallest Faroese sills and demonstrate that the larger and oldest local sills, grouped into the low-TiO2 Streymoy/Kvívík sills and the high-TiO2 Eysturoy/Sundini sills respectively (~55.5 Ma), likely formed immediately subsequent to the formation of the uppermost parts of the Enni Formation, which itself represent the latest stages of local surface magmatism at ~55.8 Ma. Gradually decreasing sill volumes coupled with successively younger ages point to systematic decrease of local igneous activity with increasing distances to active contemporaneous local rifting zones. Comparable scenarios recorded for other parts of the North Atlantic Igneous Province support our inferences regarding the nature of late-stage magmatic activity at some distances from zones of active seafloor-spreading. Comparisons between ages of Faroese igneous products versus those of e. g. central E Greenland point to a somewhat diachronous evolution pattern within this part of the North Atlantic Igneous Province subsequent to ~57.5 Ma. The lithosphere-asthenosphere boundary is commonly thought to be critical for the formation of basaltic magmas. Accordingly, the close spatial and temporal associations between many high-TiO2 and low-TiO2 Faroese rock suites are interpreted in the context of a regional version of this boundary. VL - 12 IS - 5 ER -
Information
Email: