Sultan et al. (1992 presente) d an impressiv compilatioe onf re-mote-sensing, geochemical an, d geochronologica datl a that support a variant of the McKenzie et al. (1970) mode l for the opening of the Red Sea rift Th. e Sulta ent al restoratio. findsn a best matc foh r preexisting Africa ann d Arabia geologin featurec bsy juxtaposing present-day Red Sea coastlines I.f correct thi, demonstrates thas t virtually the entire Re d Sea basin is floored by oceani crustc . The trans-Red Sea correlations presented by Sultan et al. have been addresse byd severa authorsl wit, varyinh interpretationsg . Girdler (1991) fo,r example use, thd e sam satellite imagere any d found that the coastline onls y need to be restore withid n 2 5 km of each other However. regardles, ofs one's impressio onf the Sultan et al. restoration othe, datr a are availabl whice h sugges that t theirs is not a geologically reasonabl solutione . The origina criticisl omf th e McKenzi eet al (1970. model) , which is equally applicabl teo Sultan et al., stemme d from the pres-ence of continenta basemenl itn the southernmos Ret d Sea and the Gulf of Suez (Freund 1970, Joff; e and Garfunkel 1987), Th. e 60-km-wide Danakil horst negates the possibility of completely flooring the Afar with new oceanic lithosphere. In the north, 105 ±2 km of offset has occurred along the Dead Sea transform since circa 19 Ma (Quen-nell, 1958) Allowin. onlg y this amoun ot f relativ motioe between n Sinai and Arabi necessitatea 60-9s k0m of extensio acrosn thse southern Gulf o f Suez to rejoin Red Sea coastlines. The present Gulf of Suez rift is about 90 km wide (Fig. 1), giving a Gulf of Suez 0 factor for the McKenzie et al. and Sultan et al. models of from 3 to infinity. This is completely a t odds with the subsurfac geologe y of the gulf (Angelier, 1985) whic, h is known from boreholes to be completely floored by continental crust Th. e only way to circumvent this prob-lem is to allow additional slip between Sina ani d Arabia, beyond the documented 10 km5 . The geologi evidencc againse thist however, , is very strong (Freun ed t al., 1970) . The case against coast-to-coast closure gains additional support from exploratoiy wells drille idn the Red Sea itself Man. y of these wells reached total dept h in continental basement roc k (Table 1) . I n northern Egyp att th e latitude osf Safag ana d Quseir continenta, l crust extends at least 20 km offshore (Fig. 1). In this same area, fault blocks tha wert e activ durine Mioceng Ree d Sea rifting extend an additional 25 km inland from the coast. On the matching Saudi Ara-bian margin a, discontinuou bels t o f Miocen faule t block s of about the same wi4th exists along the coastal plain from the Midyan region to south of El Wajh. The wells offshore at Burquan show that, as in Egypt, continenta crusl must bt e presen att leas 2t0 km from the coast. The combination of well and outcrop data from Egypt and Saudi Arabia demonstrate thas Ret d Sea stretche continentad crusl not w