The carbonatite-marble dykes of Abyan Province, Yemen Republic: the mixing of mantle and crustal carbonate materials revealed by isotope and trace element analysis |
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| Authors: | M J Le Bas M A O Ba-bttat R N Taylor J A Milton B F Windley P M Evins |
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| Institution: | (1) School of Ocean and Earth Science, University of Southampton, United Kingdom;(2) Department of Earth and Environmental Sciences, University of Kuwait, Kuwait;(3) Department of Geology, University of Leicester, United Kingdom;(4) School of Earth Sciences, James Cook University, Townsville, Australia |
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| Abstract: | Summary Dykes of carbonate rocks, that cut gneisses in the Lowder-Mudiah area of southern Yemen, consist of dolomite and/or calcite with or without apatite, barite and monazite. Petrographic observations, mineralogical, XRF and ICP-MS analyses reveal that some of the carbonate rocks are derived from sedimentary protoliths, whereas others are magmatic calcio- and magnesio-carbonatites some of which are mineralized with barite-monazite. The interbanded occurrence and apparent contemporary emplacement of these different rock types within individual dykes, backed by Sr–Nd isotope evidence, are interpreted to show that intrusion of mantle-derived carbonatite magma was accompanied by mobilization of crustal marbles. That took place some 840 Ma ago but the REE-mineralization is dated at ca. 400Ma.Supplementary material to this paper is available in electronic form at http://dx.doi.org/10.1007/s00710-004-0056-2 |
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