Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

Geological Magazine

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (9) Citing Articles via Google Scholar Google Scholar Articles by LAPIERRE, H. Articles by DEMANT, A. Search for Related Content GeoRef GeoRef Citation

The Mamonia Complex (SW Cyprus) revisited: remnant of Late Triassic intra-oceanic volcanism along the Tethyan southwestern passive margin

H. LAPIERRE^*, D. BOSCH, A. NARROS^*, G. H. MASCLE^*,, M. TARDY^¶ and A. DEMANT^||

^* Laboratoire Géodynamique des Chaînes Alpines, UMR-CNRS 5025, Université J. Fourier, Maison des Géosciences, B. P. 53, F. 38041 Grenoble Cedex, France
Laboratoire de Tectonophysique, UMR-CNRS 5568, Institut des Sciences de la Terre, de l’Eau et de l’Espace de Montpellier, CC049, Université de Montpellier II, Place Eugène Bataillon, F. 34095 Montpellier Cedex 05, France
^¶ Laboratoire Géodynamique des Chaînes Alpines, UMR-CNRS 5025, Université de Savoie, F. 73376 Le Bourget du Lac, France
^|| Laboratoire de Pétrologie magmatique, Université Paul Cézanne (Aix-Marseille), case courrier 441, F. 13397 Marseille Cedex 20, France

Author for correspondence: Georges.Mascle{at}ujf-grenoble.fr

Upper Triassic volcanic and sedimentary rocks of the Mamonia Complex in southwestern Cyprus are exposed in erosional windows through the post-Cretaceous cover, where the Mamonia Complex is tectonically imbricated with the Troodos and Akamas ophiolitic suites. Most of these Upper Triassic volcanic rocks have been considered to represent remnants of Triassic oceanic crust and its associated seamounts. New Nd and Pb isotopic data show that the whole Mamonia volcanic suite exhibits features of oceanic island basalts (OIB). Four rock types have been distinguished on the basis of the petrology and chemistry of the rocks. Volcanism began with the eruption of depleted olivine tholeiites (Type 1) and oceanic island tholeiites (Type 2) associated with deep basin siliceous and/or calcareous sediments. The tholeiites were followed by highly phyric alkali basalts (Type 3) interbedded with pelagic Halobia-bearing limestones or white reefal limestones. Strongly LREE-enriched trachytes (Type 4) were emplaced during the final stage of volcanic activity. Nd and Pb isotopic ratios suggest that tholeiites and mildly alkali basalts derived from partial melting of heterogeneous enriched mantle sources. Fractional crystallization alone cannot account for the derivation of trachytes from alkaline basalts. The trachytes could have been derived from the partial melting at depth of mafic material which shares with the alkali basalts similar trace element and isotopic compositions. This is corroborated by the rather similar isotopic compositions of the alkali basalts and trachytes. The correlations observed between incompatible elements (Nb, Th) and Nd and Pb isotopic initial ratios suggest that the Mamonia suite was derived from the mixing of a depleted mantle (DMM) and an enriched component of High µ (µ = ²³⁸U/²⁰⁴Pb, HIMU) type. Models using both Nd and Pb isotopic initial ratios suggest that the depleted tholeiites (Type 1) derived from a DMM source contaminated by an Enriched Mantle Type 2 component (EM2), and that the oceanic tholeiites (Type 2), alkali basalts (Type 3) and trachytes (Type 4) were derived from the mixing of the enriched mantle source of the depleted tholeiites with a HIMU component. None of the Mamonia volcanic rocks show evidence of crustal contamination. The Upper Triassic within-plate volcanism likely erupted in a small southerly Neotethyan basin, located north of the Eratosthenes seamount and likely floored by oceanic crust.

Key Words: Late Triassic volcanism • SW Cyprus • Pb–Nd • oceanic island basalts • Neotethys opening

This article has been cited by other articles:

				R. Martini, B. Peybernes, and P. Moix LATE TRIASSIC FORAMINIFERA IN REEFAL LIMESTONES OF SW CYPRUS Journal of Foraminiferal Research, July 1, 2009; 39(3): 218 - 230. [Abstract] [Full Text] [PDF]

				R. C. Maury, H. Lapierre, D. Bosch, J. Marcoux, L. Krystyn, J. Cotten, F. Bussy, P. Brunet, and F. Senebier The alkaline intraplate volcanism of the Antalya nappes (Turkey): a Late Triassic remnant of the Neotethys Bulletin de la Societe Geologique de France, July 1, 2008; 179(4): 397 - 410. [Abstract] [Full Text] [PDF]

				P. Monjoie, H. Lapierre, A. Tashko, G. H. Mascle, A. Dechamp, B. Muceku, and P. Brunet Nature and origin of the Triassic volcanism in Albania and Othrys: a key to understanding the Neotethys opening? Bulletin de la Societe Geologique de France, July 1, 2008; 179(4): 411 - 425. [Abstract] [Full Text] [PDF]

				G.H.-N. CHAN, J. MALPAS, C. XENOPHONTOS, and C.-H. LO Magmatism associated with Gondwanaland rifting and Neo-Tethyan oceanic basin development: evidence from the Mamonia Complex, SW Cyprus Journal of the Geological Society, May 1, 2008; 165(3): 699 - 709. [Abstract] [Full Text] [PDF]

				G.I. Christodoulou, G.C. Sander, and A.D. Wheatley Characterization of the Ezousas aquifer of SW Cyprus for storage recovery purposes using treated sewage effluent Quarterly Journal of Engineering Geology and Hydrogeology, August 1, 2007; 40(3): 229 - 240. [Abstract] [Full Text] [PDF]