The Oceanic Islands: Azores

  • W. I. Ridley
  • N. D. Watkins
  • D. J. MacFarlane


An island or archipelago is a geologically anomalous feature of any ocean basin. An understanding of the origin and features of any island or archipelago is, therefore, ideally obtained by the process of recognizing the associated anomalous features, formulating models to explain the features, and testing the model so produced, preferably by use of several independent approaches.


Magnetic Anomaly Spreading Rate Oceanic Island Bouguer Anomaly Azores Island 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Abdel-Monem, A., Fernandez, L. A., and Boon, G. A., 1968, Pliocene-Pleistocene minimum K-Ar ages of older eruptive centers, Eastern Azores (abstract): Trans. Am. Geophys. Union, v. 49, n. 1, p. 363.Google Scholar
  2. Archambeau, C. B., Flinn, A. E., and Lambert, D. G., 1969, Fine structure of the upper mantle: Jour. Geophys. Res., v. 74, p. 5825–5866.CrossRefGoogle Scholar
  3. Assunçao, C. F. Torre de, 1961, Estudo petrographico da ilha de S. Miguel (Acores): Commun. Serv. Geol. Port., v. 45, p. 81–176.Google Scholar
  4. Assunçao, C. F. Torre de and Canilho, M. H., 1970. Notas sobre petrografia comparada das ilhas Atlanticas: Lisbon Univ. Fac. Ciênc. Mus. e Lab. Mineral., e Geol. Bol., v. 11, p. 305–342.Google Scholar
  5. Baker, I., 1969, Petrology of the volcanic rocks of St. Helena Island, South Atlantic: Bull. Geol. Soc. Am., v. 80, p. 1283–1310.CrossRefGoogle Scholar
  6. Ball, M. M. and Harrison, C. G. H., 1969, Origin of the Gulf and Caribbean and implications regarding ocean ridge extension, migration, and shear: Gulf Coast Assoe. Geol. Soc. Trans. 19th Annual Meeting, p. 287-294.Google Scholar
  7. Banerjee, S. K., 1971, Decay of marine magnetic anomalies by ferrous ion diffusion: Nature, v. 229, p. 181–183.Google Scholar
  8. Bangher, A. R. and Sykes, L. R., 1969, Focal mechanisms of earthquakes in the Indian Ocean and adjacent regions: J. Geophys. Res., v. 74, n. 2, p. 632–649.CrossRefGoogle Scholar
  9. Barazangi, M. and Dorman, J., 1969, World seismicity maps compiled from ESSA, Coast and Geodetic Survey, epicenter data, 1961–1967: Bull. Seism. Soc. Am., v. 59, n. 1, p. 369–381.Google Scholar
  10. Barrett, D. L. and Aumento, F., 1970, The Mid-Atlantic Ridge 45°N, XL Seismic velocity, density, and layering of the crust: Can. Jour. Earth Science, v. 7, p. 1117–1124.CrossRefGoogle Scholar
  11. Bass, M. N., 1971, Variable abyssal basalt populations and their relation to sea-floor spreading rates: Earth Plan. Sci. Letters. Bath, M., 1960, Crustal structure of Iceland: J. Geophys. Res., v. 65, p. 1793–1807.Google Scholar
  12. Berthois, L., 1953, Contribution à l’étude lithologique de archipel des Azores: Commun. Serv. Geol. Port., v. 34.Google Scholar
  13. Boone, G. M. and Fernandez, L. A., 1971, Phenocrystic olivines from the eastern Azores: Mineral. Mag., v. 38, p. 165–178.CrossRefGoogle Scholar
  14. Bott, M. H. P. and Smith, R. A., 1958, The estimation of the limiting depth of gravitating bodies: Geophys. Pros., v. 6, p. 1–10.CrossRefGoogle Scholar
  15. Burke, K., Kidd, W. S. F., and Wilson, J. T., 1973, Plumes and concentric plume traces of the Eurasian Plate: Nature Physical Sciences, v. 241, p. 128–129.Google Scholar
  16. Cann. J. R., 1968, Bimodal distribution of rocks from volcanic islands: Earth Plan. Sci. Letters, v. 4, p. 479–480.CrossRefGoogle Scholar
  17. de Veiga, Ferreira, O., 1961, Afloramentos de calcario miocenico da Ilha de Santa Maria, Azores: Commun. Serv. Geol. Port., v. 45, p. 493–501.Google Scholar
  18. Drake, C. L. and Woodward, H. O., 1963, Appalachian curvature, wrench faulting and offshore structures: Trans. New York Acad. Sci., v. 26, n. 2, p. 48–63.CrossRefGoogle Scholar
  19. Drew, W., 1965, Paleomagnetic measurements in Quaternary lavas from the Azores Islands: Unpublished, Ph. D. Thesis, University of Newcastle-upon-Tyne.Google Scholar
  20. Einarrson, T., 1954, A survey of gravity in Iceland: Soc. Sci. Ist. Reykjavic, 22 p.Google Scholar
  21. Ellwood, B. B., Watkins, N. D., Amerigian, C., and Self, S., 1973, Brunhes epoch geomagnetic secular variation in the Azores: EOS (Trans. American Geophysical Union), v. 54, p. 254 (abstract).Google Scholar
  22. Esenwein, P., 1929, Zur Petrographie der Azoren: Zeitschr. für Vulkanol, v. 12, p. 108–227.Google Scholar
  23. Ewing, J. and Ewing, M., 1959, Seismic refraction measurements in the Atlantic Ocean basins, in the Mediterranean Sea, on the Mid-Atlantic Ridge, and in the Norwegian Sea: Geol Soc. Am. Bull., v. 70, p. 291–318.CrossRefGoogle Scholar
  24. Ewing, J., and Ewing, M., 1967, Sediment distribution on the mid-oceanic ridges with respect to spreading of the sea-floor: Science, v. 156, p. 1590–1591.CrossRefGoogle Scholar
  25. Fernandez, L. A., 1973, Petrology of the Nordeste Volcanic Complex, São Miguel Island, Azores: Geol. Soc. Amer. (abstracts with Programs) p. 618.Google Scholar
  26. Gaposchkin, E. M. and Lambeck, K., 1970, 1969 Smithsonian Standard Earth II: Smithsonian Astrophys. Obs. Spec. Rep. 315, 93 pp.Google Scholar
  27. Gast, P. W., 1968a, Upper mantle chemistry and evolution of the earth’s crust, in: The History of the Earth’s Crust, R. A. Phinney ed.: Princeton University Press, p. 15-27.Google Scholar
  28. Gast, P. W., 1968b, Trace element fractionation and the origin of tholeiitic and alkaline magma types: Geochim. Cosmochim. Acta, v. 32, p. 1057–1086.CrossRefGoogle Scholar
  29. Girdler, R. W., 1963, Geophysical evidence on the nature of magmas and intrusions associated with rift valleys: Bull. Volcan., v. 26, p. 34–47.CrossRefGoogle Scholar
  30. Girod, M. and Lefeure, C., 1972, The so-called andesites of the Azores: Contrib. Mineral. and Petrol., v. 35, p. 159–167.CrossRefGoogle Scholar
  31. Green, D. H., 1971, Composition of basaltic magmas as indicators of conditions of origin: Application to oceanic volcanism: Phil Trans. Roy. Soc. London, v. 268A, p. 707-725.Google Scholar
  32. Green, D. H. and Ringwood, A. E., 1967, The genesis of basaltic magmas: Contrib. Mineral, and Petrol, v. 15, p. 103–190.CrossRefGoogle Scholar
  33. Hadwen, P. and Walker, G. P. L., A geological review of the Azores, in press.Google Scholar
  34. Hanks, T. C., 1971, Model relating heat-flow values near, and vertical velocities of mass transport beneath the Oceanic Rise: J. Geophys. Res., v. 76, p. 537–544.CrossRefGoogle Scholar
  35. Heezen, B. C., Tharp, M., and Ewing, M., 1959, The floors of the oceans, 1. The North Atlantic: Geol. Soc. Am. Spec. Paper, v. 65.Google Scholar
  36. Heirtzler, J. F., Dickson, G. O., Herron, E. M., Pitman, W. C., and LePichon, X., 1968, Marine magnetic anomalies, geomagnetic field reversals and motions of the ocean floor and continents: J. Geophys. Res., v. 73, p. 2119–2136.CrossRefGoogle Scholar
  37. Isacks, B., Oliver, Jr., and Sykes, L., 1968, Seismology and the new global tectonics: J. Geophys. Res., v. 73, p. 5855–5899.CrossRefGoogle Scholar
  38. Jeremine, E., 1957, Etude microscopique des roches de la region de Furmas (S. Miguel, Acores): Commun. Serv. Geol Port., v. 38, p. 65–90.Google Scholar
  39. Kaula, W., 1970, Earth’s gravity field: relation to global tectonics: Science, v. 169, p. 982–985.CrossRefGoogle Scholar
  40. Kay, R., Hubbard, N. J., Gast, P. W., 1970, Chemical characteristics and origin of Oceanic Ridge Volcanic rocks: J. Geophys. Res., v. 75, p. 1585–1613.CrossRefGoogle Scholar
  41. Keen, M. J., 1970, Fracture zones on the Mid-Atlantic Ridge between 43°N and 44°N: Canadian Jour. Earth Sci., v. 7, p. 1352–1355.CrossRefGoogle Scholar
  42. Krause, D. C., 1965, East and West Azores fracture zones in the North Atlantic: Submarine Geology and Geophysics (17th Colston Symposium, Bristol, 1965), p. 163-173.Google Scholar
  43. Krause, D. C., 1966, Relation of the Mid-Atlantic Rift to the Azores Platform: Second Int. Ocean. Cong. (Moscow), p. 207 (abstract).Google Scholar
  44. Krause, D. C. and Watkins, N. D., 1970, North Atlantic crustal genesis in the vicinity of the Azores: Geophys. Journ. Roy. Astron. Soc., v. 19, p. 261–283.CrossRefGoogle Scholar
  45. Laughton, A. S., Whitmarsh, R. B., Rusby, J. S. M., Somers, M. L., Revie, J., McCartney, B. S., and Nafe, J. C., 1972, A continuous east-west fault on the Azores-Gibralter ridge: Nature, v. 237, p. 217–220.CrossRefGoogle Scholar
  46. Lee, W. H. K., and Taylor, P. T., 1966, Global analysis of seismic refraction measurement: Geophys. Journ. Roy. Astron. Soc., v. 11, p. 389–413.CrossRefGoogle Scholar
  47. Lee, W. H. K., and Uyeda, S., 1965, Review of heat flow data, in: Terrestrial Heat Flow (Geophysical Monograph, American Geophysical Union), v. 8, p. 87–190.CrossRefGoogle Scholar
  48. Le Pichon, X., Houtz, R., Drake, C. L., and Nafe, J. E., 1965, Crustal structure of midoceanic ridges, 1 Seismic refraction measurements: J. Geophys. Res., v. 70, p. 319–339.CrossRefGoogle Scholar
  49. Loncarevic, B. D., Mason, C. S., and Mathews, D. H., 1966, Mid-Atlantic Ridge near 45°N, 1. The median valley: Canadian Journ. Earth Sci., v. 3, p. 327–349.CrossRefGoogle Scholar
  50. Lopez Arroyo, A., and Udias, A., 1972, After shock sequence and focal parameters of the February 28, 1964 earthquake of the Azores-Gibralter Fracture Zone: Bull. Seis. Soc. America, v. 62, p. 699–720.Google Scholar
  51. Lui-Kai, M., 1966, Unpublished M. Sc. Thesis (University of Newcastle-upon-Tyne), Department of Physics.Google Scholar
  52. MacFarlane, D. J., 1968, The structure of some Atlantic Islands as deduced from gravity and other geophysical data: Ph. D. Thesis, University of London.Google Scholar
  53. MacFarlane, D. J. and Ridley, W.I., 1968, An interpretation of gravity data for Lanzarote, Canary Islands: Earth Plan. Sci. Letters, v. 6, p. 431–436.CrossRefGoogle Scholar
  54. Machado, F., 1954, Earthquake intensity, anomalies and magma chambers of Azorean Volcanoes: Trans. Am. Geophys. Union, v. 35, p. 833–837.CrossRefGoogle Scholar
  55. Machado, F., 1959, Submarine pits of the Azores plateau: Bull. Volcan., v. 11, n. 21,p. 109–116.CrossRefGoogle Scholar
  56. Machado, F., 1962, Sobre o mechismo du erupcao dos Capelinhos: Geol. Serv. Port. Memoir, n. 9, 19 p.Google Scholar
  57. Machado, F., 1965, Volcanismo das Ilhas de Cabo Verde e das Outras Ilhas Atlantidas: Junta Invest, do Ultramar (Lisbon), v. 117, 83 p.Google Scholar
  58. Machado, F. and Forjaz, V. H., 1965, Seismic swarm in the Azores Feb. 1964. Preliminary Report: Bol. Soc. Geol. Port., v. 15, p. 201–206.Google Scholar
  59. Machado, F., Quintino, J., and Monteiro, J. H., 1972, Geology of the Azores and the Mid-Atlantic Rift: Proc. XXIV Int. Geol. Cong., Sec. 3, p. 134–142.Google Scholar
  60. McBirney, A. R. and Gass, I. G., 1967, Relations of oceanic volcanic rocks of mid-ocean rises and heat flow: Earth Planet Sci. Letters, v. 2, p. 265–276.CrossRefGoogle Scholar
  61. McKenzie, D., 1972, Active tectonics of the Mediterranean region: Geophys. Jour. Roy. Astron. Soc., v. 30, p. 109–186.CrossRefGoogle Scholar
  62. McKenzie, D. P. and Morgan, W. J., 1969, Evolution of triple junctions: Nature, v. 224, p. 125–133.CrossRefGoogle Scholar
  63. Menard, H. W., 1965, Sea floor relief and mantle convection: Phys. Chem. Earth, v. 6, p. 315–364.CrossRefGoogle Scholar
  64. Miyashiro, A., Shido, F., and Ewing, M., 1969, Diversity and origin of abyssal tholeiite from the Mid-Atlantic Ridge near 24° and 30° North latitude: Contrib. Mineral. and Petrol., v. 23, p. 38–52.CrossRefGoogle Scholar
  65. Morgan, W. J., 1968, Rises, trenches, great faluts, and crustal blocks: J. Geophys. Res., v. 73, p. 1959–1982.CrossRefGoogle Scholar
  66. Morgan, W. J., 1971, Convection plumes in the lower mantle: Nature, v. 230, p. 42–43.CrossRefGoogle Scholar
  67. Muir, I. D. and Tilley, C. E., 1964, Basalts from the northern part of the rift zone of the Mid-Atlantic Ridge: J. Petrol., v. 5, p. 409–434.CrossRefGoogle Scholar
  68. Muir, I. D. and Tilley, C. E., 1966, Basalts from the northern part of the Mid-Atlantic Ridge: 11. The Atlantis collections from 30°N: J. Petrol., v. 7, p. 193–201.CrossRefGoogle Scholar
  69. Nafe, J. E. and Drake, C. L., 1969, Floor of the Atlantic—Summary of Geophysical Data, in: North Atlantic—Geology and Continental Drift (Memoir 12, Amer. Assoc. Petrol. Geol.), p. 59-87.Google Scholar
  70. Nicholls, G. D., 1965, Basalts from the deep ocean floor: Mineral Mag., v. 34, p. 373–388.CrossRefGoogle Scholar
  71. O’Hara, M. J., 1968, The bearing of phase equilibria studies in synthetic and natural systems on the origin and evolution of basic and ultrabasic rocks: Earth Sci. Rev., v. 4, p. 69–133.CrossRefGoogle Scholar
  72. Oversby, V. M., 1971, Lead in oceanic islands: Faial, Azores and Trindade: Earth Planet. Sci., Letters, v. 11, p. 401–406.CrossRefGoogle Scholar
  73. Peterson, M. N. A., Edgar, N. T., Cita, M., Gartner, S., Goll, R., Nigrini, C., and von der Borch, C., 1970, Initial reports on the deep-sea drilling project (U. S. Government printing office, Washington, D. C), v. 2, p. 424–426.Google Scholar
  74. Phillips, J. D. and Luyendyk, B. P., 1970, Central North Atlantic plate motions over the last 40 million years: Science, v. 170, p. 727–729.CrossRefGoogle Scholar
  75. Phillips, J. D., Thompson, G., Von Herzen, R. P., and Bowen, V. T., 1969, Mid-Atlantic Ridge near 43°N latitude: J. Geophys. Res., v. 74, p. 3069–3081.CrossRefGoogle Scholar
  76. Pitman, W. C. and Talwani, M., 1972, Sea floor spreading in the North Atlantic: Geol. Soc. Amer. Bull., v. 83, p. 619–646.CrossRefGoogle Scholar
  77. Pitman, W. C., Talwani, M., Heirtzler, J. R., 1971, Ages of the Atlantic Ocean from magnetic anomalies: Earth Planet. Sci. Letters, v. 11, p. 195–200.CrossRefGoogle Scholar
  78. Ridley, W. I., 1970, The petrology of the Las Canadas volcanoes, Tenerife, Canary Islands: Contrib. Mineral, and Petrol., v. 26, p. 124–160.CrossRefGoogle Scholar
  79. Ritsema, A. R., 1969, Seismic data of the West Mediterranean and the problem of oceanization: Verhand. Kon. Ned. Geol. Mijn Gen., v. 26, p. 105–120.Google Scholar
  80. Roberts, D. C., 1970, The Rif-Betic orogen in the Gulf of Cadiz: Marine Geology, v. 9, p. M31-M37.Google Scholar
  81. Saucier, H. and Roche, A., 1964, Etude paleomagnetique de laves de Faial et de Graciosa: Commun. Geol. Serv. Port., v. 48, p. 5–13.Google Scholar
  82. Schmincke, H. U., 1973, Magmatic evolution and tectonic regime in the Canary Madeira and Azores Island Groups: Geol. Soc. Amer. Bull., v. 84, p. 633–648.CrossRefGoogle Scholar
  83. Schmincke, H. U. and Weibel, M., 1972, Chemical study of rocks from Madeira, Porto Santo, and Sao Miguel, Terceira (Azores): Neuss. Jb. Miner. Abh., v. 117, p. 253–281.Google Scholar
  84. Schneider, E. D., and Vogt, P. R., 1968, Discontinuities in the history of sea-floor spreading: Nature, v. 217, p. 1212–1222.CrossRefGoogle Scholar
  85. Self, S., 1971, The Lajes ignimbrite, Iiha Terceira, Azores: Comm. Geol. Serv. Portugal, v. 55, p. 165–180.Google Scholar
  86. Serughetti, J. and Roche, A., 1968, Etude paleomagnetique de laves de l’Ile de Flores: Computes Rendus Acad. Sci. Paris, v. 267, p. 1185–1188.Google Scholar
  87. Shand, S. J., 1949, Serpentinite from oceanic rocks near the Azores: J. Geology, v. 57, p. 89–92.CrossRefGoogle Scholar
  88. Sigurdsson, H., 1970, Structural origin and Plate tectonics of the Snaefellsnes volcanic zone, Western Iceland: Earth Planet. Sci. Letters, v. 10, p. 129–135.CrossRefGoogle Scholar
  89. Skeels, D. C., 1963, An approximate solution of the problem of maximum depth in gravity interpretation: Geophysics, v. 28, p. 724–735.CrossRefGoogle Scholar
  90. Talwani, M., Le Pichon X., and Ewing, M., 1965, Crustal structure of the Mid-Ocean Ridges. 2) Computed model from gravity and seismic refraction data: J. Geophys. Res., v. 70, p. 341–352.CrossRefGoogle Scholar
  91. Tolstoy, I., 1951, Submarine topography in the North Atlantic: Bull. Geol. Soc. Am., v. 62, p. 441–450.CrossRefGoogle Scholar
  92. Torrance, K. E. and D. L. Turcotte, 1971, Structure of convection cells in mantle: J. Geophys. Res., v. 76, p. 1154–1161.CrossRefGoogle Scholar
  93. Udias, A., and Lopez Arroyo, A. 1972, Plate tectonics and the Azores-Gibralter Ridge: Nature, v. 237, p. 67–69.Google Scholar
  94. Vine, F., 1966, Spreading of the ocean floor: new evidence: Science, v. 154, p. 1405–1415.CrossRefGoogle Scholar
  95. Vogt, P. R. and Ostenso, N. A., 1966, Magnetic survey over the Mid-Atlantic Ridge between 42° and 46°N: J. Geophys. Res., v. 71, p. 4389–4412.CrossRefGoogle Scholar
  96. Walker, G. P. H. and Croasdale, R., 1971, Two Plinian-type eruptions in the Azores: J. Geol. Soc. London, v. 127, p. 17–55.CrossRefGoogle Scholar
  97. Watkins, N. D., 1968, Comments on the interpretation of linear magnetic anomalies: Pure and Applied Geophys., v. 69, p. 179–192.CrossRefGoogle Scholar
  98. Watkins, N. D. and Paster, T., 1971, Magnetic properties of igneous rocks from the ocean floor: Phil. Trans. Roy. Soc. Lond., v. A-268, p. 507–550.Google Scholar
  99. Watkins, N. D. and Richardson, A., 1971, Intrusives, extrusives, and linear magnetic anomalies: Geophys. Jour. Roy. Astron. Soc., v. 23, p. 1–13.CrossRefGoogle Scholar
  100. Weston, F. S., 1964, List of recorded volcanic eruptions in the Azores with brief reports: Boletim. do Musen e Lab. Mineral, e. Geol. Lisboa, v. 10, p. 3–18.Google Scholar
  101. Williams, C. A. and McKenzie, D., 1971, The volution of the north-east Atlantic: Nature, v. 232, p. 168–173.CrossRefGoogle Scholar
  102. Yoder, H. S. and Tilley, C. E., 1962, Origin of basalt magmas: An experimental study of natural and synthetic rock systems: J. Petrol., v. 3, p. 342–529.CrossRefGoogle Scholar
  103. Zbyszewski, G., 1963, Les phenomenes volcaniques modernes dans l’Archipel des Azores: Comm. Geol. Serv. Portugal, v. 47, 277 p.Google Scholar
  104. Zbyszewski, G. and da Veiga Ferreira, O., 1962, La Faune Miocene de l’ile de Santa Maria: Communic, de Servicos Geologicos de Portugal, v. 46, p. 247–290.Google Scholar

Copyright information

© Plenum Press, New York 1974

Authors and Affiliations

  • W. I. Ridley
    • 1
  • N. D. Watkins
    • 2
  • D. J. MacFarlane
    • 3
  1. 1.Lunar Science InstituteHoustonUSA
  2. 2.Graduate School of OceanographyUniversity of Rhode IslandKingstonUSA
  3. 3.Shell-BPLagosNigeria

Personalised recommendations