Northern Teruel Graben (Neogene), Northeastern Spain

Resumen

The Teruel graben, also named Teruel fosse (Mein etal., 1990) and Teruel basin, is located on the northeastern side of the Iberian Peninsula (Figure 1). The basin isoriented north-northeast-south-southwest and occupiesan area of approximately 100 km in length and 15 km in width. It is filled by a rather complete Neogene succession reaching 500 m in thickness (Moissenet, 1983,1989). The Teruel basin is regarded as a half-grabenbounded by several en echelon north-northeastsouth-southwest normal faults that are mainly locatedin the eastern part of the basin (Anadon and Moissenet,1996). Hanging-wall subsidence is westward of the faults, whereas footwall uplift is eastward of the faults.This structure resulted in tilting of the Neogene deposits that, in general, dip toward the east-southeast.The main tectonic lineation that controlled the formation of the basin is in contrast with the typical northwest southeast Paleogene compressional structures of the Iberian Chain (Figure 1), thus providing evidence of a gradual change in stress regime throughout the upperOligocene in this area of the northeast Iberian Peninsula(Simon, 1984). Formation of the basin is envisagedas related to the extensional movements linked to the rifting of the western Mediterranean during the Miocene (Anadon et al., 1989; Roca, 1996). In the northern part of the Teruel graben (Teruel Alfambr aregion) (Figure 1), the Neogene successionis bounded by siliciclastic and evaporate formations of Triassic age, as well as by Jurassic carbonate deposits. The oldest Neogene deposits, which un conformablyoverlie Upper Jurassic formations in the491eastern margin of the basin, have been dated as lower Aragonian (Montalvos mammal locality) (MNT, Figure2); however,