metamorphism and tectonics of a pan-african terrain in southeastern sinai — a reply

Precambrian Research, 24 (1984) 189--197 189 Elsevier Science Publishers B.V., Amsterdam -- Printed in The Netherlands

Reply

METAMORPHISM AND TECTONICS OF A PAN-AFRICAN TERRAIN IN SOUTHEASTERN SINAI - - A REPLY

A.P.S. REYMER

Ins t i tu te of Earth Sciences, Department of Geology, The Hebrew University, Jerusalem (Israel)

(Received and accepted August 10, 1983)

My presentation, discussion and conclusions concerning some aspects of Wadi Kid (southeast Sinai) geology (Reymer, 1983a) are no t "somewhat" , but very different from Shimron's contributions, as I will show below. Shimron's charge that I did not quote all of his works (many are abstracts and short reports) is curious because he omits a fair number of references himself (Shimron and Reymer, 1980; Reymer, 1981; Reymer, 1983b; Matthews et al., 1983). Few of Shimron's observations and none of his interpretations match mine, as he suggests, and I would especially like to stress that I carefully avoided undue speculation, unlike Shimron. To discuss his comments in an orderly and understandable fashion for an outside reader is greatly impaired by his failure to separate data and data analysis from inferences, interpretations and speculations. He frequently changes stratigraphic divisions and names, structural cross-sections and interpretations. This would be admissible if such changes were clearly indicated and explained. I will restrict myself to addressing some typical examples. I leave out any detailed discussion on southern Wadi Kid, since Reymer and Yogev (1983) is still in press at the time of writing and for the same reason Shimron (1983, 1984) is not available to me. I will start with some large-scale aspects of Sinai geology and then discuss some details and charges by Shimron.

LARGE SCALE CONSTRAINTS

Results of numerous geochemical and isotopical studies in the Arabian-- Nubian Shield indicate that around 700 Ma, or certainly around 650 Ma, the Arabian Shield was largely cratonized (see, e.g., Roobol et al., 1983, Table 1, for a recent overview). Tectonic, metamorphic and plutonic ac- tivity younger than ~700 - -650 Ma acted within or at the edges of a continental crust. Geochronologic studies in Sinai (Bielski et al., 1979; Halpern, 1980; Halpern and Tristan, 1981; Bielski, 1982; and some unpublished results) suggest that Sinai is no t very much different, at least isotopically, from the rest of the Arabian--Nubian Shield. Geochronologic data from

0301-9268/84/$03.00 © 1984 Elsevier Science Publishers B.V.

190

the sediments, volcanics and plutonic rocks in and around the Wadi Kid area all yield ages of 600 + 50 Ma. Thus, the Wadi Kid geology reflects the Pan-African event in its original definition (Kennedy, 1964; Jackson and Ramsay, 1980}. The above assessment reduces, for instance, the value of Shimron's (1980) paper precisely because he embarked (in this and other papers) on a speculative story without first critically looking at his data. He explicitly showed (Shimron, 1980, Fig. 11) the Kid Group deposited on oceanic crust, assuming, Qn the basis of unreliable age determinations (see below), that the Kid Group was of "Kibaran" (~ 900 Ma} age. I showed this to be an erroneous concept (Reymer, 1983a) on the basis of reliable age determinations (cited above) indicating ages of 600 + 50 Ma for the Kid Group and surrounding plutons, a post-Pan-African (measured and not "presumed") crustal thickness of more than 35 km, and my own observations and conclusions. I did not even use the large-scale assessment I have made above.

In fig. 11 of Shimron {1980) the hypothetical subduction zone is dipping southward and in Shimron (1981a) northward, with an accompanying change of 180 ° in the dip direction of the Madus shear zone (cf. Shimron, 1980, fig. 10, and 1984, fig. 2). I would conclude from such drastic changes, that the author does not know much about this shear zone. Such speculative games can be played endlessly, because no data constrian any of the models. Shimron quotes his own papers incorrectly: Shimron (1981a) as 1980c, Shimron (1981b) as 1980d and Shimron {1982) as 1981b.

Shimron's quotation of ages is puzzling: the Siedner et al. {1974} age has never been authoritatively published, the Feiran gneiss age is "in pre- parat ion" and he does not quote his own published contribution to the geochronology of Sinai (Shimron and Brookins, 1974). If he no longer believes in these results, why not give an explanation? The Shimron and Brookins data define an 'errorchron' of ~900 Ma with a suspiciously low initial 87Sr/S6Sr (for sediments) of 0.7007. By taking this age uncritically, large errors were introduced in Shimron (1980, 1981b)as outlined above. If two data points are taken from Shimron and Brookins {1974), corresponding to samples 709K1 and 709K2 which were collected close together, we obtain an 'age', ~640 Ma, and an initial 8TSr/S6Sr of 0.704, much closer to the results of Bielski (1982) and Halpern and Tristan (1981). The thorough isotopical study by Bielski (1982) is misquoted and her interpretation of the evolution of Sinai is never referred to at all. Bielski shows that the 800 Ma age of Elat schists is poorly constrained due to the wide scatter of data points and would, together with similar data from Haipern and Tristan (1981), fit a reference line of 650 Ma. In fact the oldest reliable age to date is the 734 + 17 Ma of the Sa'al volcanics, north of the Wadi Kid area (Bielski, 1982), whereas the only well-documen- ted age in the Feiran area (also considered "Kibaran" by Shimron, 1980, 1981b) is the 643 + 41 Ma age on the Sulaf granitic gneiss (Bielski, 1982; most of the ages of Bielski were already known long before their final

1 9 1

publication date, e.g., Bielski, 1980). However, the overall analogy of the geology of Sinai with the Arabian--Nubian Shield and the data from the isotope record make it quite probable that older rocks are present, but perhaps not at the surface, the reason for which I pointed out in my paper (Reymer, 1983a, p.236).

I continue questioning Shimron's logic, argumentation and style of writing by looking at one of the cornerstones for his tectonic schemes, the Dahab "ophiolite". I showed, I thought convincingly, that this ophiolite did not exist (Reymer, 1983a, fig. 4 and p. 236), but Shimron thinks otherwise in his discussion. Initially he agrees with my remark (Reymer, 1983a) that the Dahab section and in particular the two small serpentinite lenses "cannot be taken as an ophiolite, not even a dismembered one". However, Shimron (1981a) wrote that the Dahab section represents an ophiolite in the sense of the Penrose Conference definition! Because he agreed with my remark, one would suspect that the discussion is closed. However, the ophiolite idea returns "when we view the complete section of mafic volcanic rocks", etc. I repeat the rock types in this section and give, between brackets, the names Shimron gives to the corresponding rock types: intrusive xenolith-bearing andalusite--K-feldspar, quartzo-feldspathic gneiss (leptite); amphibole schists (probably calcareous meta- sediments), pelitic schist and marble (greenstones); hornblende gabbro-- diorite--granodiorite (all gabbro) of which Mittlefehldt and Ravina (1983) showed, on the basis of trace element chemistry, that it is n o t of ophiolite or island-arc signature, but rather of continental margin type, in agreement with my (Reymer, 1983a, p.236) conclusions and the assessment made above; two small metaserpentinites (harzburgite segments) incorporated in tonalitic gneiss, dated at 650--550 Ma (Reymer and Bielski, in Bielski, 1982); various small amounts of epidote--amphibolite; a thick unit of bimodal, but mainly acid, metavolcanics. Shimron tries to impress by using suggestive and misleading rock names. We could have buried the Dahab ophiolite at this stage for good (and with that Shimron 1980, 1981a, and probably 1981c, which is not available to me) were it not that Shimron continues on a confusing zig-zag path. He claims that he suggested a small mantle diapir in the Dahab--Shahira area (ophiolite now gone?) (Shimron, 1981c), whereas in fact I proposed the same thing (Reymer, 1981) (see Shimron's charge of not quoting). The Cabo-Ortegal complex in north- west Spain shows "many similarities", except that in Cabo--Ortegal a large ultramafic complex is exposed, but is not in Dahab. Shimron then refers to both the mantle diapir and ophiolite models for Cabo-Ortegal and leaves the reader behind in confusion.

Shimron writes that 350 Ma is sufficient time for the construction and destruction of numerous island arcs (he probably means as a way of building up the crust). How does he know? We address this very problem in a forthcoming paper (Reymer and Schubert, 1984) and show that 350 Ma is not enough time to explain the formation of the total continental crust

192

of the Arabian--Nubian Shield on the basis of modern island-arc addition rates. The word "paradoxically" can be removed from Shimron's next sentence when considering my data (Reymer, 1983a), this reply, the data of Mittlefehldt and Ravina (1983), Matthews et al. (1983), Bielski (1982) and Bentor (written communication, 1983, on a comprehensive review of the geology of Sinai and the Arabian--Nubian Shield, in press), and, last but not least, apparently his own (Forbes et al., in Shimron, 1984).

I would like to stress that I never mention a mantle diapir in my paper, as stated several times by Shimron (see his charge of misquoting). In my fig. 6 (Reymer, 1983a) it is nowhere present and it is only in my discussion (Reymer, 1983a, p.235 and 236) that I wrote "...a large diapir (mafic pluton?). . .". The brackets and question mark were printed to indicate uncertainty as it could be a granitic pluton, and I wrote mafic not ultramafic. It could also be a metamorphic core complex, such as found in the Eastern Desert of Egypt (Sturchio et al., 1983). I explicitly stated the lack of direct evidence "(e.g., gravimetric data)". In his discussion, Shimron suggests that the latter comment is his idea.

SHEAR ZONES

In the perhaps 75%, but certainly not 100% exposed Sinai, the evidence for shear zones according to Shimron is that they are "visible manifesta- tions". In the whole section on shear zones, the number of such zones is inversely proportional to the evidence presented for it. By again employ- ing forceful statements and the use of "major" and "mega-shear" (cf. Shimron, 1980; 1981b, etc.) Shimron tries to impress the reader, but in fact reduces his credibility. Although early shear zones or shallow-angle faults could be present [evidence for the presence of steep Pan-African faults is shown in Reymer and Yogev (1983) and Navon (1982), such important concepts need good evidence, e.g., displaced unique markers. Other features, such as the lineaments, were not addressed in my paper and I tend to accept them. One must further be aware of the scale effect: microscale shear fea tures may relate to any large-scale strain history and I am certainly not "aware" of any mylonites anywhere in the Wadi Kid area. A detailed study of one of the best known outcrops of "myloni te" (Reymer and Oertel, 1982), as recommended by Shimron (1981b, p.79) did not result in any clear indication for microscale extensive shear strains. On macroscale, possible translation is already restricted by the fact that the rock transformation zone lies within a rhyolite unit, and no displaced marker could be found. Perhaps I should further clarify, from our pre- liminary study, that the cleavage (varying from slaty to discrete crenulation cleavage) cuts the sharp transformation zone boundaries into the massive walls without any deflection, as would be expected for a foliation in a shear zone in an originally homogeneous rock (Ramsay and Graham, 1970). Moreover, we have mapped such zones elsewhere as highly discontinuous

1 9 3

and even patchy. Thus, the origin for this, and similar zones is not directly clear to me, and neither are a lot of the so-called mylonites of Shimron. However, they could represent early fractures or faults, later potential conduits for water, as the metamorphic reactions and fabrics in the rhyolite require H20 addition. I recommend Shimron to check the modern definition of mylonite (Bell and Etheridge, 1973; Hobbs et al., 1976) and the recent extensive literature on microstructures in mylonites and their interpretation. An important level of shear (decoUement) may very well be present at a deeper crustal level underlying the Wadi Kid area, since the large-scale upright fold style of DI (Navon, 1982; Reymer, 1983a; Reymer and Yogev, 1983) cannot continue indefinitely to depth.

A crucial point lies in the geology of the central Wadi Kid area, which wastherefore chosen for a very detailed mapping project by one of our students (Navon, 1982; Navon and Reymer, in preparation) and we can show unequivocally that; (1) D1 folds continue in the same style from southern Wadi Kid to the strongly D2 overprinted central region; and (2) the stratigraphy can be matched in very great detail with the sequence established in southern Wadi Kid (Reymer, 1983a; Reymer and Yogev, 1983). These two important points, not appreciated by Shimron in his discussion, allowed the construction of my map and cross-section (Reymer," 1983a, Figs. 2 and 3), which contrast with the various stratigraphic/tectonic divisions proposed by Shimron (compare Shimron and Arkin, 1978; Shim- ron, 1981b, 1982, 1984). Of course my cross-section can be improved upon and refined, and no doubt Shimron has data to do it, but that does not change any of the conclusions in my paper. Shimron, referring to central Wadi Kid, writes about "concordant mylonites". Concordant to what? Cleavage? Bedding? "...coupled with data such as the regional subhorizontal $2 schistose fabric". Since when is a regional cleavage, which, as Shimron should have mentioned, is axial planar to recumbent folds, evidence for mylonites? D2 deformation and associated cleavage in Wadi Kid is very interesting precisely because of a lack of evidence for bulk simple shear, as I pointed out (Reymer, 1983a,b). This second cleavage continues south- wards until if fades out in southern Wadi Kid, in contrast to the cross- section in Shimron's discussion (Fig. 1; see also Gaber, 1983; Reymer, 1983a); to him all this is "complex and still pronounced and beyond dispute". Few interpretations are beyond dispute in geological science and such statements are better omitted.

METAMORPHISM

In my paper (Reymer, 1983a) I used the aforementioned quartzo-feldspathic gneiss for a first constraint on the P--T conditions of metamorphism and for additional constraints on D2 tectonics (no-bulk simple shear). I drew attention to the presence of similar smaller occurrences of such gneiss throughout the Wadi Kid area (gneiss bodies occur in the southern, central

194

and northern Wadi Kid area and in an outlier of metamorphic rocks just north of the Wadi Kid area (Pezaro, 1973; and own mapping)), further enhancing the idea that melting of pelitic/greywacke rocks occurred at deeper levels, as could be expected from the high metamorphic gradient. The latter gradient can be determined independently by considering phase equilibria in central Wadi Kid, and is now confirmed by geothermobaro- metry (Navon, 1982; Matthews et al., 1983). All the intrusive quartzo- feldspathic gneisses with their highly recryst~llized metamorphic microstructures have one or more of the following minerals in common: andalusite, K-feldspar, garnet (spessartine-rich almandines), Fe-rich cordierite, sillimanite and biotite. However, in the intrusive bodies outlining what now seems to be called the "Lig mylonite", I have not found aluminosilicates. Moreover, all these bodies strike NE, perpendicular to the NW- trending D2 mineral lineation, which formed close to the peak of metamorphism (Reymer, 1983a). For each of these quartzo-feldspathic gneiss occurrences Shimron has a different name or interpretation:"leptite" (see discussion on Dahab "ophiolite" above), "blastomylonite" ("mylonites beyond dispute", but Shimron (1981a) refered to Lig anatectic leptite, linking these rocks, as I prefer to do, with the Dahab/Shahira occurrence) along the Madsus "shear zone" (cf. Reymer, 1983a), "quartzite" in southern Wadi Kid (Shimron and Bogoch, 1970) and, after I pointed out this error, converted to "albitite blastomylonite" (Shimron, 1984). He explicitly states that this "albitite" does not contain any aluminosilicates or K-feldspar. However, I have a microprobe analysis of one of the andalusite crys- tals in this rock. This analysis was made because of the faint pinkish ple- ochroism of the andalusite, which turned out to be caused by a high Fe- content. The rock contains abundant microcline perthite and also cordierite, some of which has been replaced by chlorite and sericite. Thus, the gneiss is an anatectic (low P), deformed microgranite, and not an "albitite blastomylonite". The porphyroblasts define a steeply dipping lineation, absent in albitites elsewhere in the region (Bogoch, 1981).

Shimron (1980) claimed stratigraphic sequence of 20 km in the Wadi Kid area, in sharp contrast with the few km I can account for on the basis of stratigraphy and tectonics (Reymer, 1983a, Fig. 3). Moreover, his estimate is inconsistent with the low-P/high-T metamorphism. A conservative estimate for a geothermal gradient is ~40°C km -I, which is not compatible with 20 km of sediments and mainly greenschist-facies metamorphism.

Shimron writes in his discussion, and in (1981a), about isograds, a word I carefully avoided in my paper. Evidence for the Madsus "shear zone" (interpreted elsewhere as a "suture") includes the "subtle but profound" parallelism of "the chlorite isograd" with this supposedly tectonic boundary. In Shimron (1981a; and reflected in his fig. 2, 1984) isograds of such bulk~composition-sensitive minerals as garnet and staurolite run all over the area, irrespective of lithology (ranging from pelites to acid metavolcanics), and parallel to lithologic or tectonic boundaries. Shimron is ap-

195

parently unaware of the need to study and specify reactions (some of which are continuous), bulk compositions, XH20, etc., let alone to discuss the problems related with their interpretation as isotherms or how he de- fined an isograd along a tectonic contact. Shimron continues in his discussion to claim "greenschist-facies overprint on amphibolite facies". How does he separate an "overprint" from retrograde reactions during cooling? And how does he separate "greenschist facies on greenschist-facies overprint"? Our geothermometry data (Matthews et al., 1983) do not indicate any greenschist-facies overprint, since they record amphibolite-facies tem- peratures. Localized retrogression is, therefore, interpreted by us as the usual effect of cooling and hydration. Shimron "wishes to point ou t " that the Umm Zariq Formation does not contain cordierites. I quote from Navon and Reymer (in preparation): "Identification of these porphyroblasts as cordierite is based on the shape of the pseudomorphs and on modal analyses of the replacing minerals. A count of 2500 points in three porphyroblasts yields 41% quartz, 30% sericite + muscovite, 22% chlorite, 3% biotite and 4% opaques. Assuming that quartz, biotite and opaques were present as inclusions, as suggested by the microfabric, an A1/Fe + Mg ratio of 1.5 is obtained, nearly similar to that of cordierite (1.7) and clearly different from staurolite (3.9) or garnet (0.5) and, of course, andalusite". Thus, Shimron's s tatement is baseless.

CONCLUDING REMARKS

Some of the data on Wadi Kid presented by Shimron in his discussion and earlier work, if they are correct, are compatible with my study. For instance, the Madsus "shear zone" (but no t the Lig mylonite) which com- prises, according to Shimron (Fig. 1, 1984), most of the northwestern corner of Wadi Kid, was not mapped by us, as truthfully indicated in my fig. 2 (Reymer, 1983a). If good evidence for this zone is to be presented, then it could be part of the D1 compressional phase. However, the statement that this shear zone is of "magnificent propor t ion" and presentation of fig. 4 (Shimron, 1984) are not sufficient. Why is fig. 4 a tectonic melange and not a conglomerate? Why a mylonite if the little-deformed looking boulders could have localized strain in the matrix? Many points raised by Shimron are irrelevant to my paper, others are inadequately argued or erroneous. The purpose of my paper was to show the mutual relationships between structures, metamorphism, plutonism and their ages, of a low- pressure metamorphic region, with the idea of comparing it at a later stage with other low-pressure metamorphic terrains, rather than embarking on ad hoc plate-tectonic modelling. Details will be published elsewhere (Reymer and Yogev, 1983; Navon and Reymer, in preparation). Shimron's poor, confusing and overly long discussion does not force me to change anything in my paper.

196

REFERENCES

Bell, T.H. and Etheridge, M.A., 1973. Microstructures of mylonites and their descriptive terminology. Lithos, 6: 337--348.

Bielski, M., 1980. Dating of major stages in the development of the Arabian--Nubian Massif in Sinai. Isr. Geol. Soc. Annu. Meeting, 23--27 March 1980, Ophira, Abstr., p.6.

Bielski, M., 1982. Stages in the evolution of the Sinai Peninsula. Ph.D. Thesis, The He- brew University of Jerusalem (Hebrew with English abstract), 155 pp.

Bielski, M., J~/ger, E. and Steinitz, G., 1979. The geochronology of Iqna Granite (Wadi Kid Pluton), southern Sinai. Contrib. Mineral. Petrol., 70: 159--165.

Bogoch, R., 1981. Genetic models for the Precambrian Tarr--Albitite Complex, southeastern Sinai. Geol. Surv. Isr., Current Res., pp. 6--8.

Gaber, L.J., 1983. The structural petrology of the Wadi Kid--Wadi Beda area (SE Sinai). M.Sc. Thesis, Ben-Gurion University of the Negev, Beersheva, 79 pp.

Halpern, M., 1980. Rb---Sr "Pan-African" isochron ages of Sinai igneous rocks. Geology, 8: 48--50.

Halpern, M. and Tristan, N., 1981. Geochronology of the Arabian--Nubian Shield in southern Israel and eastern Sinai. J. Geol., 89: 639--648.

Hobbs, B.E., Means, W.D. and Williams, P.F., 1976. An Outline of Structural Geology. Wiley, New York, 571 pp.

Jackson, N.J. and Ramsay, C.R., 1980. What is the "Pan-African"? A consensus is need- ed. Geology, 8: 210--211.

Kennedy, W.Q., 1964. The structural differentiation of Africa in the Pan-African (± 500 m.y.) tectonic episode. Univ. Leeds Res. Inst. Aft. Geol. Dep. Earth Sci., 8th Annu. Rep. Sci. Results, pp. 48--49.

Matthews, A., Reymer, A., Navon, O. and Cochin, Y., 1983. P - -T - -X~o conditions in the high-grade metamorphic rocks of central and northern Wadi Kid, Sinai. Isr. Geol. Soc. Annu. Meeting, 24--27 April 1983, Nazerat, Abstr., p. 53.

Mittlefehldt, D.W. and Ravina, A., 1983. Petrology and trace element chemistry of the Shahira Pass pluton. Isr. Geol. Soc. Annu. Meeting, 24--27 April 1983, Nazerat, Abstr., pp. 60--61.

Navon, O., 1982. Metamorphism and structural history of the central Wadi Kid area, southeastern Sinai. M.Sc. Thesis (manuscript), The Hebrew University, Jerusalem, 60 pp.

Navon, O. and Reymer, A.P.S., 1984. Stratigraphy, structures and metamorphism in central Wadi Kid, southeastern Sinai. Isr. J. Earth Sci. (in prep.).

Pezaro, P., 1973. The geology and petrology of the eastern margins of Jebel Ferani. M.Sc. Thesis, The Hebrew University, Jerusalem, 91 pp.

Ramsay, J.G. and Graham, R.M., 1970. Strain variation in shear belts. Can. J. Earth Sci., 7: 786--813.

Reymer, A.P.S., 1981. The geology of the Shahira area, SE Sinai. Proc. Isr. Geol. Soc. Annu. Meeting, 15--18 March 1981, Katzrin, p. 50.

Reymer, A.P.S., 1983a. Metamorphism and tectonics of a Pan-African terrain in southeastern Sinai. Precambrian Res., 19: 225--238.

Reymer, A.P.S., 1983b. Origin of horizontal cleavage in a low-pressure metamorphic terrain in Sinai. Isr. Geol. Soc. Annu. Meeting, 24--27 April 1983, Nazarat, Abstr., p. 66.

Reymer, A.P'.S. and Oertel, G., 1982. Progreasive rock transformation of a metarhyolite: chemical reactions, strain and micafabric development. Mitt. Geol. Inst. Eidg. Tech. Hochsch. Univ. Ziirich, Neue Folge, 239a: 237--240.

Reymer, A.P.S. and Yogev, A., 1983. Stratigraphy and tectonic history of the southern Wadi Kid metamorphic complex, southeastern Sinai. Isr. J. Earth Sci., 32: 105--116.

197

Reymer, A.P.S. and Schubert, G., 1984. Phanerozoic addition rates to the continental crust and crustal growth. Tectonophysics (in press).

Roobol, M.J., Ramsay, C.R., Jackson, N.J. and Darbyshire, D.P.F., 1983. Late Pro- terozoic lavas of the central Arabian Shield -- evolution of an ancient volcanic arc system. J. Geol. Soc. London, 140: 185--202.

Shimron, A.E., 1980. Proterozoic island arc volcanism and sedimentation in Sinai. Pre- cambrian Res., 12: 437--455.

Shimron. A.E., 1981a. The Dahab ophiolite and its thermal aureole. Geol. Surv. Isr., Current Res., pp. 3--6.

Shimron. A.E., 1981b. Late phase deformation and mylonite belts in Sinai: Pan-African thrust fault tectonics. Geol. Surv. Isr., Current Res., pp. 75--80.

Shimron, A.E., 1981c. The Dahab mafic---ultramafic complex, Southern Sinai P e n i n s u l a - a probable ophiolite of Late Proterozoic (Pan-African) age. Ofioliti, 6: 161--164.

Shimron. A.E., 1982. Geology and tectonics of the Tarr Complex, SE Sinai Peninsula. Geol. Surv. Isr., Current Res., pp. 73--82.

Shimron, A.E., 1984. Metamorphism and tectonics of a Pan-African terrain in southeastern Sinai - - a discussion. Precambrian Res., 24: 173--188.

Shimron A.E. and Bogoch, R., 1970. Geological map of Wadi Kid area, southeast Sinai. Isr. Geol. Soc. Annu. Meeting, 22--27 November 1970, Central and Southern Sinai (eneh, 1 map).

Shimron, A.E. and Brookins, D.G., 1974. Rb--Sr radiometric age of late Precambrian fossil-bearing and associated rocks from Sinai. Earth Planet. Sci. Lett., 24: 136--140.

Shimron, A.E. and Arkin, Y., 1978. Precambrian geology of Wadi Kid--Wadi Umm Adawi area, eastern Sinai. Reconnaissance map 1:25,000 and explanatory notes. Geol. Surv. Isr., Rep. MM/1/78.

Shimron, A.E. and Reymer, A.P.S., 1980. Structural evolution of the Kid Group, a multiple deformed orogenic sequence in southeast Sinai. Isr. Geol. Soc. Annu. Meet- ing, Ophira, Abstr., pp. 33--34.

Siedner, G., Shimron, A. and Pringle, J.R., 1974. Age relationship in basement rocks of the Sinai Peninsula. Int. Meet. Geochronol. Cosmochron. and Isotope Geol., Paris, Abstr.

Sturchio, N.C., Sultan, M. and Batiza, R., 1983. Geology and origin of Meatiq Dome, Egypt: a Precambrian metamorphic core complex? Geology, 11: 72--76.

metamorphism and tectonics of a pan-african terrain in southeastern sinai — a reply

Documents