Geochronology of some Canadian dike swarms; contribution to the volcano-tectonic evolution of the archipelago

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doi: 10.1016/0377-0273(85)90003-4
Authors:Féraud, Gilbert; Giannérini, Gérard; Campredon, Robert; Stillman, Chris J.
Author Affiliations:Primary:
Facul. Sci. Nice, Lab. Geol. et Geochem., Nice, France
Other:
Trinity Coll., Dep. Geol., Ireland
Volume Title:Journal of Volcanology and Geothermal Research
Source:Journal of Volcanology and Geothermal Research, 25(1-2), p.29-52. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0377-0273
Publication Date:1985
Note:In English. 50 refs.; illus. incl. 3 tables, geol. sketch maps
Summary:K/Ar and 39Ar/40Ar age data and geometric observations on the dyke swarms which intrude three of the Canary Islands are presented. On La Gomera a second radial fissure structure superimposed dykes of 5.4-5.2 m.y. on older ones dated at 10.5-7.0 m.y. The dyke swarms of the Anaga and Teno peninsulas of Tenerife are 5.8-3.6 m.y. old; those on the Pedro Gil ridges are 0.43 m.y. old. The dykes of the basal complex of Fuerteventura give clear 39Ar/40Ar plateaux away from plutons and disturbed age spectra, probably due to thermal metamorphism near them. An important magmatic phase from 24 to 17 m.y. is indicated on the main NNE-SSW volcano-tectonic axis, followed by further activity in the NW of the Jandia peninsula from 15.4 to 14.2 m.y. Fissural volcanism is shown to be important in these islands. Brief episodes may be correlated with the migration of the lithosphere over a fixed hot-spot. The orientation of the dyke swarms may reflect the regional palaeostress which affected the lithosphere during their intrusion; these directions agree with known contemporaneous NW African tectonics. [R.E.S.]
Subjects:Absolute age; Ar/Ar; Basaltic composition; Basalts; Cenozoic; Dates; Dike swarms; Dikes; Geochronology; Igneous rocks; Intrusions; Neogene; Petrology; Tertiary; Volcanic rocks; Atlantic Ocean Islands; Canary Islands; Fuerteventura; Tenerife; K-Ar; La Gomera
Coordinates:N274500 N291500 W0180000 W0180000
Abstract Numbers:86M/0017
Record ID:1985074076
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom
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