The rarity of lithic
fragments implies either that the source rocks were severely
weathered or that the grains were recycled. The matrix and/or cement (2–13%) are composed mainly of clays, silica or iron oxides.
All samples examined contain iron oxides either as dark brownblack grains or as coatings on some of the detrital grains. The relative proportions of the detrital mineral are given inTable 1.
From the modal composition analysis, the detrital grains modes
are recast inTable 1to include the derived QFL indices. Note the
dominance of monocrystalline over polycrystalline quartz, K-feldspar over plagioclase and the low content of lithic clasts, to yield
an average QFL composition of 87:11:2. In thePettijohn (1975)
scheme, these rocks are classified as quartz arenites and arkosic
arenites; a conclusion shared bySalem et al. (2001) and Salem
(2001)for similar rocks from other areas in Sinai. The slight enrichment of K-feldspar over plagioclase and the rarity of rock fragments are attributed either to prolonged weathering,
transportation or recycling