Abstract
A clear model of structures and associated stress fields of a volcano can provide a framework in which to study and monitor activity. We propose a volcano-tectonic model for the dynamics of the summit of Piton de la Fournaise (La Reunion Island, Indian Ocean). The summit contains two main pit crater structures (Dolomieu and Bory), two active rift zones, and a slumping eastern sector, all of which contribute to the actual fracture system. Dolomieu has developed over 100 years by sudden large collapse events and subsequent smaller drops that include terrace formation. Small intra-pit collapse scars and eruptive fissures are located along the southern floor of Dolomieu. The western pit wall of Dolomieu has a superficial inward dipping normal fault boundary connected to a deeper ring fault system. Outside Dolomieu, an oval extension zone containing sub-parallel pit-related fractures extends to a maximum distance of 225 m from the pit. At the summit the main trend for eruptive fissures is N80°, normal to the north–south rift zone. The terraced structure of Dolomieu has been reproduced by analogue models with a roof to width ratio of approximately 1, suggesting an original magma chamber depth of about 1 km. Such a chamber may continue to act as a storage location today. The east flank has a convex–concave profile and is bounded by strike-slip fractures that define a gravity slump. This zone is bound to the north by strike-slip fractures that may delineate a shear zone. The southern reciprocal shear zone is probably marked by an alignment of large scoria cones and is hidden by recent aa lavas. The slump head intersects Dolomieu pit and may slide on a hydrothermally altered layer known to be located at a depth of around 300 m. Our model has the summit activity controlled by the pit crater collapse structure, not the rifts. The rifts become important on the mid-flanks of the cone, away from pit-related fractures. On the east flank the superficial structures are controlled by the slump. We suggest that during pit subsidence intra-pit eruptions may occur. During tumescence, however, the pit system may become blocked and a flank eruption is more likely. Intrusions along the rift may cause deformation that subsequently increases the slump’s potential to deform. Conversely, slumping may influence the east flank stress distribution and locally control intrusion direction. These predictions can be tested with monitoring data to validate the model and, eventually, improve monitoring.
Similar content being viewed by others
References
Accocella V, Korme T, Salvini F (2003) Mechanism of fault formation along the axial zone of the Ethiopian Rift. J Struct Geol 25:503–513
Bachèlery P (1981) Le Piton de la Fournaise: Etude Volcanologique, Structurale et Pétrologique. PhD thesis, University of Clermont Ferrand, France:1–257
Bachèlery P, Chevallier P, Gratier JP (1983) Volcanologie: Caractères structuraux des éruptions historiques du Piton de la Fournaise (Ile de la Réunion). C R Acad Sci Paris 296:1345–1350
Battaglia J, Bachèlery P (2003) Dynamic dyke propagation deduced from tilt variations preceding the March 9, 1998, eruption of the Piton de la Fournaise volcano. J Volcanol Geotherm Res 120:289–310
Bory de St. Vincent (1804) Voyages dans les quatre principales iles des mers d’Afrique, Paris
Cecchi E, van Wyk de Vries B, Lavest JM, Harris A, Davies M (2003) N-view reconstruction: a new method for morphological modelling and deformation measurement in volcanology. J Volcanol Geotherm Res 123:181–201
Cecchi E, van Wyk de Vries B, Lavest J-M (2004) Flank spreading and collapse of weak-cored volcanoes. Bull Volcanol 67:72–91
Delorme H, Bachèlery P, Blum PA, Cheminée JL, Delarue JF, Delmond JC, Hirn A, Lepine JC, Vincent PM, Zlotnicki J (1989) March 1986 eruptive episodes at Piton de la Fournaise volcano (Reunion Island). J Volcanol Geotherm Res 36:199–208
Donnadieu F (2000) Déstabilisation des édifices volcaniques par les cyptodômes: Modélisation analogique et approche numérique. PhD thesis, University of Clermont-Ferrand, France:1–256
Freund R (1974) Kinematics of transform and transcurrent faults. Tectonophysics 21:93–134
Froger J-L, Fukushima Y, Briole P, Staudacher T, Souriot T, Villeneuve N (2004) The deformation field of the August 2003 eruption at Piton de la Fournaise, Reunion Island, mapped by ASAR interferometry. Geophys Res Lett 31:L14601, DOI 10.1029/2004GL020479
Fukushima Y, Cayol V, Durand P (2005) Finding realistic dike models from interferometric synthetic aperture radar data: the February 2000 eruption at Piton de la Fournaise. J Geophys Res 110:B03206, DOI 10.1029/2004JB003268
Gillot P-Y, Nativel P, Condomines M (1990) Geochronologie du Piton de la Fournaise. In: Lénat J-F (ed) Le Volcanisme de La Réunion. Centre de Recherches Volcanologiques, Clermont Ferrand, France: 243–256
Kelfoun K (1999) Processus de croissance et de déstabilisation des dômes de lave du volcan Merapi (Java centrale, Indonésie). PhD thesis, University of Clermont-Ferrand, France:1–261
Kornprobst J, Boivin P, Lénat J-F, Bachèlery P, Bonneville A, Dupont P, Lecointre J, Seidel J-L, Thomas P, Vincent P (1984) Le Piton de la Fournaise, ile de la Reunion. In: Prévision et Surveillance des Eruptions Volcaniques. Proceedings, Clermont Ferrand, France:75–82
Labazuy P, Charbonnier S, Staudacher T, Oehler J-F (2004a) New insights on the December 2002 pit crater at Piton de la Fournaise from self potential and GPS surveys. EGU 1st General Assembly, Nice, France, 25–30 April 2004, EGU04-03226
Labazuy P, Saracco G, Lénat J-F, Charbonnier S, Mauri G (2004b) EM Tomography and modeling of the hydrothermal system of Piton de la Fournaise, Reunion Island. IAVCEI General Assembly, Pucon, Chile, 15–19 November 2004
Lacroix A (1936) Le Volcan actif de l’ile de La Réunion et ses produits. Gauthier Villars (ed) Paris, pp 1–297
Lénat J-F, Bachèlery P (1990) Structure et fonctionnement de la zone centrale du Piton de la Fournaise. In: Lénat J-F (ed) Le Volcanisme de La Réunion. Centre de Recherches Volcanologiques, Clermont Ferrand, France:257–296
Lénat J-F, Fitterman D, Jackson DB, Labazuy P (2000) Geoelectrical structure of the central zone of Piton de la Fournaise volcano (Réunion). Bull Volcanol 62:75–89
Lénat J-F, Bachèlery P, Desmulier F (2001) Genese du champ de lave de l’Enclos Fouqué: une éruption d’envergure exceptionnel du Piton de la Fournaise (Réunion au 18ieme siècle). Bulletin de la Société Géologique de France 172:177–188
Murray JB (1988) The influence of loading by lavas on the siting of volcanic eruption vents on Mt Etna. J Volcanol Geotherm Res 35:121–139
Okubo CH, Martel SJ (1998) Pit crater formation on Kilauea volcano, Hawaii. J Volcanol Geotherm Res 86:1–18
Reid ME, Sisson TW, Brien DL (2001) Volcano collapse promoted by hydrothermal alteration and edifice shape, Mount Rainier, Washington. Geology 29:779–782
Roche O, van Wyk de Vries B, Druitt TH (2001) Sub-surface structures and collapse mechanisms of summit pit craters. J Volcanol Geotherm Res 105:1–18
Rowland SK, Garbeil H (2000) Slopes of oceanic basalt volcanoes. Geophys Monogr 116:223–247
Rymer H, van Wyk de Vries B, Stix J, Williams-Jones G (1998) Pit crater structure and processes governing persistent activity at Masaya volcano, Nicaragua. Bull Volcanol 59:345–355
Stieltjes L (1985) Carte des coulées historiques du volcan de la Fournaise (Ile de la Réunion, Ocean Indien). Bureau de Recherches Géologiques et Minières
van Wyk de Vries B, Matela R (1998) Styles of volcano-induced deformation: numerical models of substratum flexure, spreading and extrusion. J Volcanol Geotherm Res 81:1–18
van Wyk de Vries B, Kerle N, Petrey D (2000) A sector collapse forming at Casita, Nicaragua. Geology 28:167–170
Walker GPL (1988) Three Hawaiian calderas: an origin through loading by shallow intrusions? J Geophys Res 93:14773–14784
Walter TR, Troll VR (2001) Formation of caldera periphery faults, an experimental study. Bull Volcanol 63:191–203
Walter TR, Troll VR, Cailleau B, Belousov AB, Schmincke H-U, Amelung F, Bogaard Pvd (2005) Rift zone reorganization through flank instability in ocean island volcanoes: an example from Tenerife, Canary Islands. Bull Volcanol 67:281–291
Acknowledgements
This work was funded by a PNRN and ACI grant to van Wyk de Vries from the CNRS. Ample assistance was given by the Observatory on Piton de La Fournaise, especially from Dr. Thomas Staudacher. This paper was significantly improved by the helpful reviews of Dr. Francesco Mazzarini and Prof. Stephen Self, and edits from Dr. Andrew Harris. Fruitful conversations with JF Lénat and P Labazuy improved the manuscript. Thanks also to Dr. Luke Wooller for his suggestions and to Nerissa Lindenfelser for helpful comments.
Author information
Authors and Affiliations
Corresponding author
Additional information
Editorial resposibility: A Harris
Rights and permissions
About this article
Cite this article
Carter, A., van Wyk de Vries, B., Kelfoun, K. et al. Pits, rifts and slumps: the summit structure of Piton de la Fournaise. Bull Volcanol 69, 741–756 (2007). https://doi.org/10.1007/s00445-006-0103-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00445-006-0103-4