This paper provides the first results of a structural study in a cross-section in the Central Pyrenees
(South Pyrenean Zone, North of Biescas), bordered on the north by Palaeozoic rocks of the Axial Zone.
The geometric features of the folds, their orientations and relationships with the foliation are detailed from
the structural analysis. Asymmetric south-verging chevron folds, with an E-W axis gently plunging or
subhorizontal, are predominant. They admit the regional foliation as the axial plane foliation, with an E-W
of medium strike and dips of 50º northwards. Advanced structural studies will allow a more detailed
knowledge of the processes originating the described structures and may specify the alpine deformation in
the palaeozoic rocks within this region