Figure 2
Distribution of “in situ” magmatics of the west Mediterranean and allochthonous volcanoclastics of the Apennines.
(A) Oligocene-Aquitanian (between ~33/32 and ~20 Ma): intrusives (red circle), volcanics (red triangle) and allochthonous volcanoclastics (elongated red triangle without rim shows presumed position; green numbers in italics; see Suppl. dataset S4). Site 13: buried andesite volcano of the early Oligocene. White arrows: 1 = pre-Oligocene (>33 Ma), SE-directed subduction beneath the orogen of Alpine Age (OAA); 2 = Post-Burdigalian (<16 Ma), WNW-directed subduction of African lithosphere; this reconstruction considers that subduction was absent in the Oligocene - Burdigalian time. (B) Burdigalian (~20–16 Ma): intrusives (black circle), volcanics (black triangle) and allochthonous volcanoclastics (elongated gray triangle); Langhian-Tortonian (between ~16 and 7.5 Ma): intrusives (yellow circle), volcanics (black rimmed yellow triangle) and allochthonous volcanoclastics (elongated yellow triangle). In the Burdigalian, tholeiitic lavas accompanied the calc-alkaline magmatism of andesitic and silicic type as the continental rifting reached the stage of oceanic spreading in the Sardinia-Provence and north Algerian basins respectively on the east and on the west of the Catalan-Tunisian fracture zone (CTFZ). The scheme shows the proposed position of the WNW subduction hinge zone at ~6.3 (Vavilov opening) and ~1.67 Ma (Marsili opening), the Apennine outcrops of the allochthonous volcanoclastic rocks and the hypothetical sites of “lost” volcanic edifices and adjacent sedimentary lows which, according to the geodynamic interpretation (see Guerrera et al., 1998 and Cibin et al., 2001 in the Suppl. info), were originally sited in the Tyrrhenian OAA (offshore Sardinia-Corsica). Dotted line: the lithosphere-asthenosphere section of Fig. 6A. The figure was created by the author with the use of plotmap software41.
