Four successive episodes of Late Pan-African dikes in the central Elat area, southern Israel

Abstract

Katzir, Y., Litvinovsky, B., Eyal, M., Zanvilevich, A., and Vapnik, Y. 2006. Four successive episodes of Late Pan-African dikes in the central Elat area, southern Israel.lsr. J. Earth Sci. 55: 69-93. Four successive Late Pan-African dike suites are recognized in the central Elat area: (I) microdiorite and lamprophyre; (2) dacite porphyry with subordinate andesite and fcldspathic (Fsp) rhyolite porphyry; (3) quartz porphyry and Fsp-rhyolite porphyry with minor trachydolerite and trachyandesite; (4) trachydolerite, mostly high-Ti. Dike swarms formed over the period of -600 Ma to 530 Ma. The dike episodes alter­ nated with plutonic. volcanic. and sedimentary events. Microdiorite and lamprophyre from suite I correspond to calc-alkaline, medium- to high-K trachyandesite. Dacite porphyry is prevalent in suite 2 and forms together with augite-bearing andesite and rhyolite a high-K calc-alkaline series. In suite 3 silicic rocks are dominant; they are alkaline (NK/A >D.9) and have chemical characteristics of A-type granites. Among the trachydolerites from suites 3 and 4, high-Ti varieties are abundant (2.8-2.9 wt% and 3.3-4.5 wt% TiO:!, respectively). Trachydolerites are enriched in REE, Zr, Y, Ti, and P. Although Late Pan-African dikes are postorogenic, magmas of the first two suites were derived from mantle sources that are characteristic of a subduction-related environment of active continental margins. Trachydolerites-3 and -4 were produced, however, from sources enriched in asthenospheric components. Late Pan-African dike swarms similar to those described in southern Israel are extremely abundant through­ out the Sinai Peninsula and Eastern Desert of Egypt. Significant overlap of composi­ tions in mafic dike rocks from southern Israel and the same rock types from southern Sinai suggest similar sequence and sources of dikes over a large region.