Nova Terra 52

metaperidotites and showing a main foliation (S C ) paral- lel to their boundaries (Figure 4). The traces of the contacts between tectonostrati- graphic units in the hanging wall to the San Pedro thrust are mylonitic. As a preliminary description, the contact between the Upper Schist-Metagranitoid Unit and the Mérida Ophiolite is defined by a ductile shear zone that includes mylonites (after mafic and ultramafic rocks, metasedimentary rocks and metagranites; Figure 7(e)), and a set of variably strained rocks towards more distal sections (Trujillanos detachment). Kinematic criteria (Figure 7(e)) and the NW-SE trend of stretching lineation (Figure 9(a)) indicate consistent top-to-the-SSE shear sense for the mylonites in the core of the shear zone. The deflection of the boundaries and main foliation of the metagranitoid massifs of the Upper Schist- Metagranitoid Unit towards the Trujillanos detachment is also a consistent top-to-the-SSE shear sense indicator at the macroscale (Figures 3 and 4(b)). The trend of stretching lineations in the hanging wall (Upper Schist- Metagranitoid Unit), footwall (Mafic-ultramafic Unit) and mylonites of this latter shear zone is consistently NW-SE (Figure 9(a,b)). The contact between the Mérida Ophiolite and the Lower Gneiss Unit is also mylonitic (Magdalena thrust; Figure 7(f)). A preliminary kinematic analysis of this contact provided no consistent results, but the trend of stretching lineations within the Lower Gneiss Unit is similar (NW-SE) to that of the overlying units (Figure 9(c)). The contact between the Upper Schist-Metagranitoid Unit and the Carija Unit is marked by mylonites after limestones (Figure 7(b)) and siliciclas- tic rocks (black calc-schists) (Carija detachment). Stretching lineations trend NW-SE (Figure 9(d)), whereas kinematic criteria indicate a consistent top-to-the-NNW sense of shear (Figure 7(b)). The traces of all of these contacts are sinuous and run parallel to the main Figure 9. Stereoplots showing the orientation of stretching lineations in the Mérida Massif. (a) Upper Schist-Metagranitoid Unit and Trujillanos detachment. (b) Mafic-ultramafic Unit (Mérida Ophiolite). (c) Lower Gneiss Unit (Magdalena Gneisses). (d) Carija detachment. INTERNATIONAL GEOLOGY REVIEW 11 Tectonostratigraphy of the Mérida Massif