1. Introduction The Jurassic succession of Gebel Maghara offers the best and most comprehensive succession of Jurassic strata in Egypt (Jenkins 1990). It represents a wide va- riety of continental, deltaic, nearshore siliciclastic and carbonate shelf environments (Al Far 1966, Picard and Hirsch 1987), which contain a rich macrobenthic fau- na characterized above all by brachiopods, bivalves, gastropods, and corals. Apart from taxonomic studies, this fauna has received no attention in the past. The succession has been investigated from a strati- graphic point of view (e. g., Al Far 1966, Picard and Hirsch 1987), and most of the benthic macrofauna has been dealt with from a taxonomic point of view (e. g., Douvillé 1916, 1925, Arkell et al. 1952, Said and Barakat 1958, Farag and Gatinaud 1960, Hirsch 1980, Parnes 1984, Parnes 1988, Hegab 1989, 1991, Feld- man et al. 1991, 2012). Attempts to establish biostratigraphic and sedimen- tologic frameworks have been made in the publica- tions just mentioned, but great uncertainties still exist, especially with respect to the stage boundaries. Al- though some ammonites were identified from the Jurassic of G. Maghara (Douvillé 1916, Arkell et al. 1952, Parnes 1984, 1988), their occurrence is patchy. Moreover, most of the benthic faunal elements such as bivalves, corals, and brachiopods are environmentally controlled and hence their stratigraphic significance is comparatively difficult to ascertain. However, quanti- Newsletters on Stratigraphy, Vol. 48/1 (2015), 23–46 Article Published online November 2014; published in print January 2015 Quantitative biostratigraphy of the Middle to Upper Jurassic strata of Gebel Maghara (Sinai, Egypt) Ahmed Awad Abdelhady 1 * and Franz Theodor Fürsich 2 With 14 figures Abstract. As age-diagnostic fossils are rare in the Middle to Upper Jurassic sedimentary succession of Gebel Maghara, North Sinai, Egypt, and in order to ensure maximal stratigraphic resolution, chronostrati- graphic boundaries were determined based on quantitative biostratigraphy. A data matrix comprising 231 macrofaunal taxa in 93 samples from four sections has been processed with the Unitary Association (UA) Method. This led to construction of a sequence of 29 UAs (maximal sets of actually or virtually coexisting taxa), which have been grouped into 14 laterally reproducible association zones. The UA method allowed an in-depth analysis of the stratigraphically conflicting taxa, enabled the biostratigraphic subdivision of the stud- ied interval, and also provided stratigraphic correlation among the measured sections and with the Tethyan ammonite zones. Key words. Quantitative biostratigraphy, Unitary Association, Macrofauna, Jurassic, Gebel Maghara, Egypt © 2014 Gebrüder Borntraeger, Stuttgart, Germany DOI: 10.1127/nos/2014/0053 www.borntraeger-cramer.de 0078-0421/2014/0053 $ 6.00 Authors’ addresses: * Corresponding author 1 Geology Department, Faculty of Science, Minia University, 61519 Minia, Egypt. E-Mail: alhady2003@yahoo.com 2 FG Paläoumwelt, Geozentrum Nordbayern der Universität Erlangen, Loewenichstrasse 28, 91054 Erlangen, Germany. E-Mail: franz.fuersich@fau.de eschweizerbart_xxx