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listed above is separated from the rest ones within this unit by mechanical contacts with crustal bearing, since no juxtaposition of lithologies with contrasting tecto- nothermal evolution (see below) is observed. Geochemical data obtained from the mafic lenses in equivalent lithostratigraphic series of SW Iberia were interpreted as indicative of a continental arc setting (Sánchez Lorda et al . 2014; Sánchez-Lorda et al . 2016). This, plus the dominantly granitoid versus negligible mafic lithological composition of the Upper Schist- Metagranitoid Unit (Figure 3), suggest this unit repre- sents an internally coherent tectonic slice with continen- tal (or continental arc) affinity. 3.4. Cambrian carbonate-rich series: Carija Unit This carbonate-rich, meta-sedimentary succession of variably strained rocks is exposed northwest of Merida town (Figure 3), around the Carija hill. Strain is concen- trated along its basal boundary (Figure 7(b)) and decreases progressively upwards. The basal part consists of black calc-schists that rest below a series in which fine-grained, banded grey-white marbles alternate with fine-grained dark grey-light grey dolomitic marbles and yellow-brown marbles. The lower part is dominantly calcareous and homogeneous in mineral (>95% calcite) and geochemical composition, whereas the upper part is dolomitic and shows features (Sr/Fe and Sr/Mn) that suggest dolomitization related to late diagenetic pro- cesses, likely connected to the intrusion of granitic rocks (see further description by Fernández Caliani et al . 1996). The upper and lower parts are separated by a horizon rich in banded chert. This series has been ascribed to the Early Cambrian period (Insúa Márquez et al . 2003), and is considered correlative to other carbo- nate-rich Early Cambrian successions of SW Iberia (e.g. Bandrés 2001; Sánchez-García et al . 2010). 3.5. Ordovician strata The youngest sedimentary series that is now exposed as metamorphic rocks in the study area corresponds to a succession of meta-sandstones, meta-conglomerates, quartzites, and slates (Figure 7(c)) that occurs to the north of the Mérida Massif (Figure 3). The series is cut by a major fault, so its basal section is not exposed in the study area. The lower part consists of coarse-grained meta-sandstones (quartz-rich micro-conglomerates), which are covered by quartzites and orthoquartzites that alternate with slates. Quartzite beds are thinner upwards while slates become more abundant. This part of the series has been ascribed to the Early Ordovician period (Tremadocian-Floian), and is considered a SW Iberian correlative to the (Arenig) Armorican quartzite (Gutiérrez-Marco et al . 2002; Insúa Márquez et al . 2003). The series culminates with black slates and minor layers of black quartzites exposed within, whose age has been considered to be Middle Ordovician (Llanvirn-Llandeil) (Insúa Márquez et al . 2003). 3.6. Cenozoic cover The crystalline basement of the Mérida Massif is discor- dantly covered by a wide variety of Cenozoic sedimen- tary rocks. Since Cenozoic processes are not the focus of this contribution, no distinction has been made in the geological map between sequences of different age and composition. Previous works have divided this Cenozoic cover into informal units according to their age (Miocene through to Holocene), location, and sedimentary envir- onment (Insúa Márquez et al . 2003). The oldest Cenozoic deposit is represented by Miocene conglomerates and arkosic sandstones, fol- lowed by sandstones and conglomerates, and then red silt and clay and minor sandstones. This continental series is succeeded by Miocene arkosic sandstones, which are then covered by a Pliocene-Pleistocene suc- cession of conglomerates, sandstones and silt. Other Pleistocene and Holocene deposits include carbonated deposits (caliche), carbonated crusts, glacis deposits (irregular pebbles, gravel, and minor silt), fluvial terraces (rounded conglomerates, sandstones, and silt), alluvial fans, and aeolian sands. 4 . Regiona l structure and metamorphism The youngest regional structure of the Mérida Massif is a set of NE-dipping, high-angle faults that cuts across the contacts of the Miocene sedimentary rocks (RP-1; Figure 3) and locally juxtaposes the crystalline basement against the Cenozoic cover (Figure 7(d)). Tectonic trans- port is consistent to the SW. Displacement for all these thrusts, as deduced from offsets in pre-fault lithological contacts, is limited, probably in the range of tens of metres at most. Some of the sinuous trace of the basal contact of the Cenozoic cover near these thrusts could be explained by open folds. Besides such direct evidence of Alpine tectonics, it should be noted that most of the exposure of the Mérida Massif occurs in a small pene- plain that stands 30–60 metres above the areas located to the SW, S, and SE of the Guadiana river, whose trace in the surroundings of Mérida town could be controlled by some other Alpine thrusts with similar displacement (vertical offset at 30–60 metres) and kinematics (RP-2; Figure 3) (Vegas et al . 2012). The carbonated crusts, proposed to be Pleistocene-Holocene in age (Insúa INTERNATIONAL GEOLOGY REVIEW 9 Tectonostratigraphy of the Mérida Massif