García Cuevas, C.Giner Robles, J. L.2014-12-092014-12-092001http://hdl.handle.net/10272/9484The study of c-axes distribution from sparry grains that fill microveins were used to define maximum horizontal extension directions (<j3) in two zones ofiberian Chain (Cameros Basin and Alto Tajo zone, Castellana Branch). A strong similitude between the (o3 directions defined for the Cameros Basin and the Alto Tajo zone (NNO-SSE, NNE-SSO and NE-SO) supports the idea that these extension directions are defining episodes of extension with regional character. The NNO-SSE extension direction has been associated with the older episode of micro-veins opening (perhaps before the Upper Cretaceous). This episode has been associated with the extensional event responsible of Cameros Basin opening (Upper jurassic-LoweCretaceous). The others two younger directions of extension (NNE-SSO and NE-SO) could be associate with the more important deformantional events of Tertiary for the Castellana Branch: Guadarrama (Capote et a I., 1990) and Altomira episodes (Muñoz-Martín, 1998). These deformantional events also has been described in the Cameros BasinspaAtribución-NoComercial-SinDerivadas 3.0 Españahttp://creativecommons.org/licenses/by-nc-nd/3.0/es/Iberian ChainCalcite veinsC-axes, extension orientationsjournal articleopen access