Bulletin of Volcanology

, 81:11 | Cite as

Understanding the origin of magmatic necks: insights from Mt. Etna volcano (Italy) and analogue models

  • M. FittipaldiEmail author
  • S. Urbani
  • M. Neri
  • D. Trippanera
  • V. Acocella
Research Article


Magmatic necks are commonly found in volcanic areas, and they often exhibit a homogeneous structure with a cylindrical shape and a diameter of up to several hundreds of metres. Their massive and uniform structure poses a space problem for their emplacement in the brittle crust. Here, we use field data and analogue models to investigate how necks may emplace at shallow levels. Field analysis focuses on characterising the geometric, structural and magmatic features of two necks outcropping in the eroded portions of Mt. Etna, Italy. These are homogeneous and massive intrusive bodies, related to a single episode of emplacement at 400–600 m below the paleosurface. We further investigated their possible emplacement mechanism through analogue models, injecting vegetable oil within (a) a flat sand pack and (b) a sand cone. Dikes form with both configurations, erupting to the surface through vents. However, dikes injected within the cone are characterised by a larger thickening at shallow levels, in correspondence with the vent, where a neck-like structure forms. This suggests that the gravitational load imposed by a volcanic edifice provides the most suitable conditions for the development of magmatic neck, as the downslope shear stresses enhance the deformation of the cone slope during shallow dike emplacement promoting shallow dilation and thickening of the dike. Therefore, topography should be a further factor enhancing the development of necks, in addition to those mechanisms previously proposed. Our results are consistent with natural examples of feeder dikes thickening towards the surface and dikes transitioning to necks, supporting the reliability of the proposed conceptual model.


Intrusion Dike-to-neck transition Topography Volcanic edifice 

Supplementary material

445_2019_1273_MOESM1_ESM.doc (47 kb)
ESM 1 (DOC 47 kb)
445_2019_1273_Fig12_ESM.jpg (364 kb)
Fig. S1

Field view of Neck 2. (JPG 364 kb)

445_2019_1273_Fig13_ESM.jpg (332 kb)
Fig. S2

Detailed picture showing the homogeneous texture and several mm to cm-sized phenocrysts of pyroxene. (JPG 332 kb)

445_2019_1273_Fig14_ESM.jpg (484 kb)
Fig. S3

Band of thermal alteration along the contact between Neck 2 and Py deposit. (JPG 484 kb)

445_2019_1273_Fig15_ESM.jpg (246 kb)
Fig. S4

a) figure showing the mean strike direction of the dikes (yellow line) that is radial to the Ellittico caldera paleosummit; b) main faults affecting the eastern flank of Mt. Etna. (JPG 245 kb)

445_2019_1273_MOESM2_ESM.doc (30 kb)
Table S1 (DOC 30 kb)
445_2019_1273_MOESM3_ESM.doc (32 kb)
Table S2 (DOC 32 kb)


  1. Acocella V, Neri M (2003) What makes flank eruptions? The 2001 Etna eruption and its possible triggering mechanisms. Bull Volcanol 65:517–529. CrossRefGoogle Scholar
  2. Acocella V, Neri M (2009) Dike propagation in volcanic edifices: overview and possible developments. Tectonophysics 471:67–77. CrossRefGoogle Scholar
  3. Acocella V, Neri N, Behncke B, Bonforte A, Del Negro C, Ganci G (2016) Why does a mature volcano need new vents? The case of the new southeast crater at Etna. Front Earth Sci 4:67. CrossRefGoogle Scholar
  4. Azzaro R, Bonforte A, Branca S, Guglielmino F (2013) Geometry and kinematics of the fault systems controlling the unstable flank of Etna volcano (Sicily). J of Volcanol Geotherm Res 251:5–15CrossRefGoogle Scholar
  5. Billi A, Acocella V, Funiciello R, Giordano G, Lanzafame G, Neri M (2003) Mechanisms for ground-surface fracturing and incipient slope failure associated with the 2001 eruption of Mt. Etna, Italy: analysis of ephemeral field data. J Volcanol Geotherm Res 122:281–294. CrossRefGoogle Scholar
  6. Branca S, Coltelli M, De Beni E, Wijbrans J (2008) Geological evolution of Mount Etna volcano (Italy) from earliest products until the first central volcanism (between 500 and 100 ka ago) inferred from geochronological and stratigraphic data. Intern J Earth Sci 97:135–152. CrossRefGoogle Scholar
  7. Branca S, Coltelli M, Groppelli G (2011a) Geological evolution of a complex basaltic startovolcano: Mount Etna, Italy. Ital J Geosci (Boll Soc Geol It) 130(3):306–317. CrossRefGoogle Scholar
  8. Branca S, Coltelli M, Groppelli G, Lentini F (2011b) Geological map of Etna volcano, 1:50.000 scale. It J Geosci (Boll Soc Geol It) 130(3):00–00. CrossRefGoogle Scholar
  9. Brown RJ, Kavanagh J, Sparks RSJ, Tait M, Field M (2007) Mechanically disrupted and chemically weakened zones in segmented dike systems cause vent localization: evidence from kimberlite volcanic systems. Geology 35(9):815–818CrossRefGoogle Scholar
  10. Bruce PM, Huppert HE (1990) Solidification and melting along dikes by the laminar flow of basaltic magma. In: Ryan MP (ed) Magma transport and storage. Wiley, London, pp 87–101Google Scholar
  11. Calvari S, Groppelli GL, Pasquarè G (1994) Preliminary geological data on the south-western walls of Valle del Bove, Mt. Etna (Sicily). Acta Vulcanol 5:15–30Google Scholar
  12. Calvari S, Tanner LH, Groppelli GL, Norini G (2004) A comprehensive model for the opening of the Valle del Bove depression and hazard evaluation for the eastern flank of Etna volcano. In: “Etna volcano laboratory”, Bonaccorso, Calvari Coltelli, Del Negro, Falsaperla (Eds.), AGU (Geophysical monograph), 143 65–75Google Scholar
  13. Carey RJ, Houghton B, Sable J, Wilson C (2007) Contrasting grain size and componentry in complex proximal deposits of the 1886 Tarawera basaltic Plinian eruption. Bull Volcanol 69(8):903–926CrossRefGoogle Scholar
  14. Corsaro RA, Neri M, Pompilio M (2002) Paleo-environmental and volcano-tectonic evolution of the south-eastern flank of Mt. Etna during the last 225 ka inferred from volcanic succession of the «Timpe», Acireale, Sicily. J Volcanol Geotherm Res 113:289–306. CrossRefGoogle Scholar
  15. De Beni E, Branca S, Coltelli M, Groppelli G, Wijbrans J (2011) 40Ar/39Ar isotopic dating of Etna volcanic succession. It J Geosci (Boll Soc Geol It) 130(3):00–00. CrossRefGoogle Scholar
  16. Delaney PT, Pollard DD (1981) Deformation of host rocks and flow of magma during growth of minette dikes and breccia bearing intrusions near Ship Rock, New Mexico. USGS Prof Pap 1202:61Google Scholar
  17. Dieterich JH (1988) Growth and persistence of Hawaiian volcanic rift zones. J Geophys Res Solid Earth 93(B5):4258–4270. CrossRefGoogle Scholar
  18. Ferlito C, Cristofolini R (1989) Geologia dell’area sommitale dell’Etna. Boll Acc Gioenia Sci Nat 22:357–380Google Scholar
  19. Ferrari L, Garduno VH, Neri M (1991) I dicchi della Valle del Bove, Etna: un metodo per stimare le dilatazioni di un apparato vulcanico. Mem Soc Geol It 47:495–508Google Scholar
  20. Francalanci L, Lucchi F, Keller J, De Astis G, Tranne CA (2013) Eruptive, volcano-tectonic and magmatic history of the Stromboli volcano (north-eastern Aeolian archipelago). Geol Soc Lond Mem 37(1):397–471. CrossRefGoogle Scholar
  21. Galindo I, Gudmundsson A (2012) Basaltic feeder dykes in rift zones: geometry, emplacement, and effusion rates. Nat Hazards Earth Syst Sci 12:3683–3700. CrossRefGoogle Scholar
  22. Galland O, Holohan E, De Vries BVW, Burchardt S (2015) Laboratory modelling of volcano plumbing systems: a review. In: Nemeth K (ed) Advances in volcanology. Springer, Berlin, Heidelberg, pp 1–68Google Scholar
  23. Geshi N, Kusmoto S, Gudmundsson A (2010) Geometric difference between non-feeder and feeder dikes. Geology 38:195–198. CrossRefGoogle Scholar
  24. Giammanco S, Melián G, Neri M, Hernández PA, Sortino F, Barrancos J, López M, Pecoraino G, Perez NM (2016) Active tectonic features and structural dynamics of the summit area of Mt. Etna (Italy) revealed by soil CO2 and soil temperature surveying. J Volcanol Geotherm Res 311:79–98. CrossRefGoogle Scholar
  25. Gray TGF (1992) Handbook of crack opening data: Cambridge, UK, Abington Publishing, 96 pGoogle Scholar
  26. Hallett RB (1992) Volcanic geology of the Rio Puerco necks: New Mexico Geological Society. Guidebook 43:135–144Google Scholar
  27. Hooten JA, Ort MH (2002) Peperite as a record of early-stage phreatomagmatic fragmentation processes: an example from the Hopi Buttes volcanic field, Navajo Nation, Arizona, USA. J Volcanol Geotherm Res 114(1–2):95–106CrossRefGoogle Scholar
  28. Keating GN, Valentine GA, Kier DJ, Perry FV (2008) Shallow plumbing systems for small-volume basaltic volcanoes. Bull Volcanol 70:563–582. CrossRefGoogle Scholar
  29. Kieffer G (1985) Evolution structural et dynamique d’un grand volcan poligénique: Stades d’edification et activitè actuelle de l’Etna (Sicile). Univ Clermont-Ferrand II Clermont-Ferrand France, DissertationGoogle Scholar
  30. Kiyosugi K, Connor CB, Wetmore PH, Ferwerda BP, Germa AM, Connor LJ, Hintz AR (2012) Relationship between dike and volcanic conduit distribution in a highly eroded monogenetic volcanic field: San Rafael, Utah, USA. Geology 40:695–698CrossRefGoogle Scholar
  31. Kwon CW, Sohn YK (2008) Tephra-filled volcanic neck (diatreme) of a mafic tuff ring at Maegok, Miocene Eoil Basin, SE Korea. Geosci J 12:317–329CrossRefGoogle Scholar
  32. Lanzafame G, Leonardi A, Neri M, Rust D (1997) Late overthrust of the Appenine-Maghrebian Chain at the NE periphery of Mt. Etna, Italy. C R Acad Sci Paris 324:325–332Google Scholar
  33. Lefebvre NS, White JDL, Kjarsgaard BA (2012) Spatter-dike reveals subterranean magma diversions: consequences for small multivent basaltic eruptions. Geology 40(5):423–426CrossRefGoogle Scholar
  34. Lentini F, Carbone S, Guarnieri P (2006) Collisional and postcollisional tectonics of the Apenninic-Maghrebian orogen (southern Italy). Geol Soc Am Spec Pap 409:57–81Google Scholar
  35. Lucchi F, Santo AP, Tranne CA, Peccerillo A, Keller J (2013) Volcanism, magmatism, volcano-tectonics and sea-level fluctuations in the geological history of Filicudi (western Aeolian archipelago). Geol Soc Lond Mem 37(1):113–153. CrossRefGoogle Scholar
  36. Marsh BD (1996) Solidification fronts and magmatic evolution. Min Mag 60:5–40CrossRefGoogle Scholar
  37. Marsh BD (2013) On some fundamentals of igneous petrology. Contrib Mineral Petrol 166:665e690CrossRefGoogle Scholar
  38. Marsh BD (2015) Magma chambers. In: The encyclopedia of volcanoes, second edn, pp 185–201Google Scholar
  39. McGuire WJ (1983) Prehistoric dyke trends on Mount Etna: implications for magma transport and storage. Bull Volcanol 46:9–22. CrossRefGoogle Scholar
  40. McGuire WJ, Pullen AD (1989) Location and orientation of eruptive fissures and feeder dykes at Mount Etna; influence of gravitational and regional stress regimes. J Volcanol Geotherm Res 38:325–244. CrossRefGoogle Scholar
  41. Motoki A, Campos TF, Fonseca VP, Motoki KF (2012) Subvolcanic neck of Cabugi Peak, state of Rio Grande do Norte, Brazil, and origin of its landform. Rem: Revista Escola de Minas 65(2)Google Scholar
  42. Neri M, Acocella V, Behncke B, Giammanco S, Mazzarini F, Rust D (2011) Structural analysis of the eruptive fissures at Mount Etna (Italy). Ann Geophys 54(5):464–479. CrossRefGoogle Scholar
  43. Norini G, Acocella V (2011) Analogue modeling of flank instability at Mount Etna: understanding the driving factors. J Geophys Res Solid Earth 116:B07206. CrossRefGoogle Scholar
  44. Patané G, Agostino I, La Delfa S, Leonardi R (2009) Evolution of volcanism around the eastern sector of Mt. Etna, inland and offshore, in the structural framework of eastern Sicily. Phys Earth Planet Inter 173(3–4):306–316CrossRefGoogle Scholar
  45. Re G, White JD, Muirhead JD, Ort MH (2016) Subterranean fragmentation of magma during conduit initiation and evolution in the shallow plumbing system of the small-volume jagged rocks volcanoes (Hopi Buttes Volcanic Field, Arizona, USA). Bull of Volcanol 78(8):55CrossRefGoogle Scholar
  46. Rubin AM (1995) Propagation of magma-filled cracks. Annu Rev Earth Planet Sci 23(1):287–336. CrossRefGoogle Scholar
  47. Ruch J, Pepe S, Casu F, Solaro G, Pepe A, Acocella V, Neri M, Sansosti E (2013) Seismo-tectonic behavior of the Pernicana Fault System (Mt Etna): a gauge for volcano flank instability? J Geophys Res Solid Earth 118:4398–4409. CrossRefGoogle Scholar
  48. Siniscalchi A, Tripaldi S, Neri M, Balasco M, Romano G, Ruch J (2012) Schiavone D (2012) flank instability structure of Mt Etna inferred by a magnetotelluric survey. J Geophys Res 117:B03216. CrossRefGoogle Scholar
  49. Solaro G, Acocella V, Pepe S, Ruch J, Neri M, Sansosti E (2010) Anatomy of an unstable volcano through InSAR data: multiple processes affecting flank instability at Mt. Etna in 1994-2008. J Geophys Res 115:B10405. CrossRefGoogle Scholar
  50. Sparks RSJ, Baker L, Brown RJ, Field M, Schumacher J, Stripp G, Walters A (2006) Dynamical constraints on kimberlite volcanism. J Volcanol Geotherm Res 155:18–48CrossRefGoogle Scholar
  51. Thielicke W, Stamhuis EJ (2014) PIVlab-towards user-friendly, affordable and accurate digital particle image velocimetry in MATLAB. J Open Res Soft 2(1).
  52. Townsend M, Pollard DD, Jhonson K, Culha C (2015) Jointing around magmatic dikes as a precursor to the development of volcanic plugs. Bull Volcanol 77:92. CrossRefGoogle Scholar
  53. Vigneresse JL, Tikoff B, Améglio L (1999) Modification of the regional stress field by magma intrusions and formation of tabular granitic plutons. Tectonophysics 302:203–224. CrossRefGoogle Scholar
  54. White JDL, Ross PS (2011) Maar-diatreme volcanoes: a review. J Volcanol Geotherm Res 201(1–4):1–29CrossRefGoogle Scholar
  55. Wright TL, Klein FW (2014) Two hundred years of magma transport and storage at Kilauea Volcano, Hawaii. 1790e2008. U.S. Geological Survey Professional Paper, Washington, D.C,

Copyright information

© International Association of Volcanology & Chemistry of the Earth's Interior 2019

Authors and Affiliations

  1. 1.Dipartimento ScienzeUniversità Roma TreRomeItaly
  2. 2.Osservatorio Etneo, Sezione di CataniaIstituto Nazionale di Geofisica e VulcanologiaCataniaItaly
  3. 3.Physical Sciences and Engineering DivisionKing Abdullah University of Science and TechnologyThuwalSaudi Arabia

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