El anticlinal de Manzanedanuevas aportaciones al análisis estructural del sinclinorio de Truchas (Cabrera Alta, León)

Résumé

The Manzaneda anticline (Cabrera Alta, León) represents a N110ºE trending tectonic structure plunging towards the NW along the closure of the Truchas Synclinorium. It is cored on quartzites (Lower Ordovician) and affected by a complex joint network associated with quartz veins. The anticline is strongly tectonised and eroded, showing a narrow quartz-dike several meters long. Although, the dike disrupts thin beds of slates, in some cases, thick quartzite banks are also involved. So far, the anticline is affected by a reverse fault that uplifts the southern flank and slightly tilts it towards the NW. This fault is segmented along strike and cut by subsequent faults that displace the thrust front. In addition, major structures in the area (reverse and strike-slip faults) are covered by Tertiary sediments, indicating their Pre-Miocene age. In general, the slaty-cleavage developed in the overlying pelitic rocks is penetrative and it has a relative constant NW-SE striking axial-plane pattern. Such cleavage is deformed by kinkbands and crenulation, indicating a complex deformational history. Furthermore, the overall structure of the Manzaneda anticline can be interpreted as being related to the Hercynian deformation with little evidence of Alpine tectonics.