Micrographs of some BBMs samples. For location of the corresponding outcrops, see Figure 4 (JN) and Figure 5 (other samples). Crossed nicols except (C), plane-polarized light, and (G), backscattered-electron image. S_m: main foliation. A: Metadetrital, pebbly marble from the Amter road (outcrop 1a), ∼1 m above the unconformity (Fig. 6C). B: Magnesian marble from the same road-cut, ∼50 m above (A) (marble lens 1b). C: Metadetrital banded marbles of Oued Jnane Nich lens (JN, Fig. 4); the dashed line marks the limit between two elementary layers, calcite-rich and clastic-free, respectively, interpreted as S₀. D: Same outcrop, calc-mylonite facies. E: Calc-silicate bed, likely clastic and including minute pebbles (left area); same location as (B). F: Meta-argillite layer interbedded with banded marbles (lens 1c). G: Dolomite-rich calc-silicate bed (Oued Ljouj lens). The aggregates of calcite + serpentinized forsterite in dolomite matrix are interpreted as calcite + forsterite pseudomorphs after diopside. H: Banded phyllitic marble, same outcrop as (F); talc and muscovite are retrograde.